os/persistentdata/persistentstorage/sqlite3api/TEST/TCL/tcldistribution/generic/tclIO.c
changeset 0 bde4ae8d615e
     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/os/persistentdata/persistentstorage/sqlite3api/TEST/TCL/tcldistribution/generic/tclIO.c	Fri Jun 15 03:10:57 2012 +0200
     1.3 @@ -0,0 +1,9474 @@
     1.4 +/* 
     1.5 + * tclIO.c --
     1.6 + *
     1.7 + *	This file provides the generic portions (those that are the same on
     1.8 + *	all platforms and for all channel types) of Tcl's IO facilities.
     1.9 + *
    1.10 + * Copyright (c) 1998-2000 Ajuba Solutions
    1.11 + * Copyright (c) 1995-1997 Sun Microsystems, Inc.
    1.12 + * Portions Copyright (c) 2007-2008 Nokia Corporation and/or its subsidiaries. All rights reserved.  
    1.13 + *
    1.14 + * See the file "license.terms" for information on usage and redistribution
    1.15 + * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
    1.16 + *
    1.17 + * RCS: @(#) $Id: tclIO.c,v 1.61.2.23 2007/05/24 19:31:55 dgp Exp $
    1.18 + */
    1.19 +
    1.20 +#include "tclInt.h"
    1.21 +#include "tclPort.h"
    1.22 +#include "tclIO.h"
    1.23 +#include <assert.h>
    1.24 +#if defined(__SYMBIAN32__) && defined(__WINSCW__)
    1.25 +#include "tclSymbianGlobals.h"
    1.26 +#define dataKey getdataKey(3)
    1.27 +#endif 
    1.28 +
    1.29 +#ifndef TCL_INHERIT_STD_CHANNELS
    1.30 +#define TCL_INHERIT_STD_CHANNELS 1
    1.31 +#endif
    1.32 +
    1.33 +
    1.34 +/*
    1.35 + * All static variables used in this file are collected into a single
    1.36 + * instance of the following structure.  For multi-threaded implementations,
    1.37 + * there is one instance of this structure for each thread.
    1.38 + *
    1.39 + * Notice that different structures with the same name appear in other
    1.40 + * files.  The structure defined below is used in this file only.
    1.41 + */
    1.42 +
    1.43 +typedef struct ThreadSpecificData {
    1.44 +
    1.45 +    /*
    1.46 +     * This variable holds the list of nested ChannelHandlerEventProc 
    1.47 +     * invocations.
    1.48 +     */
    1.49 +    NextChannelHandler *nestedHandlerPtr;
    1.50 +
    1.51 +    /*
    1.52 +     * List of all channels currently open, indexed by ChannelState,
    1.53 +     * as only one ChannelState exists per set of stacked channels.
    1.54 +     */
    1.55 +    ChannelState *firstCSPtr;
    1.56 +#ifdef oldcode
    1.57 +    /*
    1.58 +     * Has a channel exit handler been created yet?
    1.59 +     */
    1.60 +    int channelExitHandlerCreated;
    1.61 +
    1.62 +    /*
    1.63 +     * Has the channel event source been created and registered with the
    1.64 +     * notifier?
    1.65 +     */
    1.66 +    int channelEventSourceCreated;
    1.67 +#endif
    1.68 +    /*
    1.69 +     * Static variables to hold channels for stdin, stdout and stderr.
    1.70 +     */
    1.71 +    Tcl_Channel stdinChannel;
    1.72 +    int stdinInitialized;
    1.73 +    Tcl_Channel stdoutChannel;
    1.74 +    int stdoutInitialized;
    1.75 +    Tcl_Channel stderrChannel;
    1.76 +    int stderrInitialized;
    1.77 +
    1.78 +} ThreadSpecificData;
    1.79 +
    1.80 +#if !defined(__SYMBIAN32__) || !defined(__WINSCW__)
    1.81 +static Tcl_ThreadDataKey dataKey;
    1.82 +#endif
    1.83 +
    1.84 +/*
    1.85 + * Static functions in this file:
    1.86 + */
    1.87 +
    1.88 +static ChannelBuffer *	AllocChannelBuffer _ANSI_ARGS_((int length));
    1.89 +static void		ChannelTimerProc _ANSI_ARGS_((
    1.90 +				ClientData clientData));
    1.91 +static int		CheckChannelErrors _ANSI_ARGS_((ChannelState *statePtr,
    1.92 +				int direction));
    1.93 +static int		CheckFlush _ANSI_ARGS_((Channel *chanPtr,
    1.94 +				ChannelBuffer *bufPtr, int newlineFlag));
    1.95 +static int		CheckForDeadChannel _ANSI_ARGS_((Tcl_Interp *interp,
    1.96 +				ChannelState *statePtr));
    1.97 +static void		CheckForStdChannelsBeingClosed _ANSI_ARGS_((
    1.98 +				Tcl_Channel chan));
    1.99 +static void		CleanupChannelHandlers _ANSI_ARGS_((
   1.100 +				Tcl_Interp *interp, Channel *chanPtr));
   1.101 +static int		CloseChannel _ANSI_ARGS_((Tcl_Interp *interp,
   1.102 +				Channel *chanPtr, int errorCode));
   1.103 +static void		CommonGetsCleanup _ANSI_ARGS_((Channel *chanPtr,
   1.104 +				Tcl_Encoding encoding));
   1.105 +static int		CopyAndTranslateBuffer _ANSI_ARGS_((
   1.106 +				ChannelState *statePtr, char *result,
   1.107 +				int space));
   1.108 +static int		CopyBuffer _ANSI_ARGS_((
   1.109 +				Channel *chanPtr, char *result, int space));
   1.110 +static int		CopyData _ANSI_ARGS_((CopyState *csPtr, int mask));
   1.111 +static void		CopyEventProc _ANSI_ARGS_((ClientData clientData,
   1.112 +				int mask));
   1.113 +static void		CreateScriptRecord _ANSI_ARGS_((
   1.114 +				Tcl_Interp *interp, Channel *chanPtr,
   1.115 +				int mask, Tcl_Obj *scriptPtr));
   1.116 +static void		DeleteChannelTable _ANSI_ARGS_((
   1.117 +				ClientData clientData, Tcl_Interp *interp));
   1.118 +static void		DeleteScriptRecord _ANSI_ARGS_((Tcl_Interp *interp,
   1.119 +				Channel *chanPtr, int mask));
   1.120 +static int              DetachChannel _ANSI_ARGS_((Tcl_Interp *interp,
   1.121 +				Tcl_Channel chan));
   1.122 +static void		DiscardInputQueued _ANSI_ARGS_((ChannelState *statePtr,
   1.123 +				int discardSavedBuffers));
   1.124 +static void		DiscardOutputQueued _ANSI_ARGS_((
   1.125 +				ChannelState *chanPtr));
   1.126 +static int		DoRead _ANSI_ARGS_((Channel *chanPtr, char *srcPtr,
   1.127 +				int slen));
   1.128 +static int		DoWrite _ANSI_ARGS_((Channel *chanPtr, CONST char *src,
   1.129 +				int srcLen));
   1.130 +static int		DoReadChars _ANSI_ARGS_ ((Channel* chan,
   1.131 +				Tcl_Obj* objPtr, int toRead, int appendFlag));
   1.132 +static int		DoWriteChars _ANSI_ARGS_ ((Channel* chan,
   1.133 +				CONST char* src, int len));
   1.134 +static int		FilterInputBytes _ANSI_ARGS_((Channel *chanPtr,
   1.135 +				GetsState *statePtr));
   1.136 +static int		FlushChannel _ANSI_ARGS_((Tcl_Interp *interp,
   1.137 +				Channel *chanPtr, int calledFromAsyncFlush));
   1.138 +static Tcl_HashTable *	GetChannelTable _ANSI_ARGS_((Tcl_Interp *interp));
   1.139 +static int		GetInput _ANSI_ARGS_((Channel *chanPtr));
   1.140 +static int		HaveVersion _ANSI_ARGS_((Tcl_ChannelType *typePtr,
   1.141 +				Tcl_ChannelTypeVersion minimumVersion));
   1.142 +static void		PeekAhead _ANSI_ARGS_((Channel *chanPtr,
   1.143 +				char **dstEndPtr, GetsState *gsPtr));
   1.144 +static int		ReadBytes _ANSI_ARGS_((ChannelState *statePtr,
   1.145 +				Tcl_Obj *objPtr, int charsLeft,
   1.146 +				int *offsetPtr));
   1.147 +static int		ReadChars _ANSI_ARGS_((ChannelState *statePtr,
   1.148 +				Tcl_Obj *objPtr, int charsLeft,
   1.149 +				int *offsetPtr, int *factorPtr));
   1.150 +static void		RecycleBuffer _ANSI_ARGS_((ChannelState *statePtr,
   1.151 +				ChannelBuffer *bufPtr, int mustDiscard));
   1.152 +static int		StackSetBlockMode _ANSI_ARGS_((Channel *chanPtr,
   1.153 +				int mode));
   1.154 +static int		SetBlockMode _ANSI_ARGS_((Tcl_Interp *interp,
   1.155 +				Channel *chanPtr, int mode));
   1.156 +static void		StopCopy _ANSI_ARGS_((CopyState *csPtr));
   1.157 +static int		TranslateInputEOL _ANSI_ARGS_((ChannelState *statePtr,
   1.158 +				char *dst, CONST char *src,
   1.159 +				int *dstLenPtr, int *srcLenPtr));
   1.160 +static int		TranslateOutputEOL _ANSI_ARGS_((ChannelState *statePtr,
   1.161 +				char *dst, CONST char *src,
   1.162 +				int *dstLenPtr, int *srcLenPtr));
   1.163 +static void		UpdateInterest _ANSI_ARGS_((Channel *chanPtr));
   1.164 +static int		WriteBytes _ANSI_ARGS_((Channel *chanPtr,
   1.165 +				CONST char *src, int srcLen));
   1.166 +static int		WriteChars _ANSI_ARGS_((Channel *chanPtr,
   1.167 +				CONST char *src, int srcLen));
   1.168 +
   1.169 +
   1.170 +/*
   1.171 + *---------------------------------------------------------------------------
   1.172 + *
   1.173 + * TclInitIOSubsystem --
   1.174 + *
   1.175 + *	Initialize all resources used by this subsystem on a per-process
   1.176 + *	basis.  
   1.177 + *
   1.178 + * Results:
   1.179 + *	None.
   1.180 + *
   1.181 + * Side effects:
   1.182 + *	Depends on the memory subsystems.
   1.183 + *
   1.184 + *---------------------------------------------------------------------------
   1.185 + */
   1.186 +
   1.187 +void
   1.188 +TclInitIOSubsystem()
   1.189 +{
   1.190 +    /*
   1.191 +     * By fetching thread local storage we take care of
   1.192 +     * allocating it for each thread.
   1.193 +     */
   1.194 +    (void) TCL_TSD_INIT(&dataKey);
   1.195 +}   
   1.196 +
   1.197 +/*
   1.198 + *-------------------------------------------------------------------------
   1.199 + *
   1.200 + * TclFinalizeIOSubsystem --
   1.201 + *
   1.202 + *	Releases all resources used by this subsystem on a per-thread
   1.203 + *	basis.  Closes all extant channels that have not already been 
   1.204 + *	closed because they were not owned by any interp.  
   1.205 + *
   1.206 + * Results:
   1.207 + *	None.
   1.208 + *
   1.209 + * Side effects:
   1.210 + *	Depends on encoding and memory subsystems.
   1.211 + *
   1.212 + *-------------------------------------------------------------------------
   1.213 + */
   1.214 +
   1.215 +	/* ARGSUSED */
   1.216 +void
   1.217 +TclFinalizeIOSubsystem(void)
   1.218 +{
   1.219 +    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
   1.220 +    Channel *chanPtr = NULL;	/* Iterates over open channels. */
   1.221 +    ChannelState *statePtr;	/* State of channel stack */
   1.222 +    int active = 1;		/* Flag == 1 while there's still work to do */
   1.223 +
   1.224 +    /*
   1.225 +     * Walk all channel state structures known to this thread and
   1.226 +     * close corresponding channels.
   1.227 +     */
   1.228 +
   1.229 +    while (active) {
   1.230 +
   1.231 +	/*
   1.232 +	 * Iterate through the open channel list, and find the first
   1.233 +	 * channel that isn't dead. We start from the head of the list
   1.234 +	 * each time, because the close action on one channel can close
   1.235 +	 * others.
   1.236 +	 */
   1.237 +
   1.238 +	active = 0;
   1.239 +	for (statePtr = tsdPtr->firstCSPtr;
   1.240 +	     statePtr != NULL;
   1.241 +	     statePtr = statePtr->nextCSPtr) {
   1.242 +	    chanPtr = statePtr->topChanPtr;
   1.243 +	    if (!(statePtr->flags & CHANNEL_DEAD)) {
   1.244 +		active = 1;
   1.245 +		break;
   1.246 +	    }
   1.247 +	}
   1.248 +
   1.249 +	/*
   1.250 +	 * We've found a live channel.  Close it.
   1.251 +	 */
   1.252 +
   1.253 +	if (active) {
   1.254 +
   1.255 +	    /*
   1.256 +	     * Set the channel back into blocking mode to ensure that we 
   1.257 +	     * wait for all data to flush out.
   1.258 +	     */
   1.259 +	    
   1.260 +	    (void) Tcl_SetChannelOption(NULL, (Tcl_Channel) chanPtr,
   1.261 +					"-blocking", "on");
   1.262 +	    
   1.263 +	    if ((chanPtr == (Channel *) tsdPtr->stdinChannel) ||
   1.264 +		(chanPtr == (Channel *) tsdPtr->stdoutChannel) ||
   1.265 +		(chanPtr == (Channel *) tsdPtr->stderrChannel)) {
   1.266 +		/*
   1.267 +		 * Decrement the refcount which was earlier artificially 
   1.268 +		 * bumped up to keep the channel from being closed.
   1.269 +		 */
   1.270 +		
   1.271 +		statePtr->refCount--;
   1.272 +	    }
   1.273 +	    
   1.274 +	    if (statePtr->refCount <= 0) {
   1.275 +		/*
   1.276 +		 * Close it only if the refcount indicates that the channel 
   1.277 +		 * is not referenced from any interpreter. If it is, that
   1.278 +		 * interpreter will close the channel when it gets destroyed.
   1.279 +		 */
   1.280 +		
   1.281 +		(void) Tcl_Close(NULL, (Tcl_Channel) chanPtr);
   1.282 +	    } else {
   1.283 +		/*
   1.284 +		 * The refcount is greater than zero, so flush the channel.
   1.285 +		 */
   1.286 +		
   1.287 +		Tcl_Flush((Tcl_Channel) chanPtr);
   1.288 +		
   1.289 +		/*
   1.290 +		 * Call the device driver to actually close the underlying 
   1.291 +		 * device for this channel.
   1.292 +		 */
   1.293 +		
   1.294 +		if (chanPtr->typePtr->closeProc != TCL_CLOSE2PROC) {
   1.295 +		    (chanPtr->typePtr->closeProc)(chanPtr->instanceData, NULL);
   1.296 +		} else {
   1.297 +		    (chanPtr->typePtr->close2Proc)(chanPtr->instanceData,
   1.298 +						   NULL, 0);
   1.299 +		}
   1.300 +		
   1.301 +		/*
   1.302 +		 * Finally, we clean up the fields in the channel data 
   1.303 +		 * structure since all of them have been deleted already. 
   1.304 +		 * We mark the channel with CHANNEL_DEAD to prevent any 
   1.305 +		 * further IO operations
   1.306 +		 * on it.
   1.307 +		 */
   1.308 +		
   1.309 +		chanPtr->instanceData = NULL;
   1.310 +		statePtr->flags |= CHANNEL_DEAD;
   1.311 +	    }
   1.312 +	}
   1.313 +    }
   1.314 +
   1.315 +    TclpFinalizeSockets();
   1.316 +    TclpFinalizePipes();
   1.317 +}
   1.318 +
   1.319 +
   1.320 +/*
   1.321 + *----------------------------------------------------------------------
   1.322 + *
   1.323 + * Tcl_SetStdChannel --
   1.324 + *
   1.325 + *	This function is used to change the channels that are used
   1.326 + *	for stdin/stdout/stderr in new interpreters.
   1.327 + *
   1.328 + * Results:
   1.329 + *	None
   1.330 + *
   1.331 + * Side effects:
   1.332 + *	None.
   1.333 + *
   1.334 + *----------------------------------------------------------------------
   1.335 + */
   1.336 +
   1.337 +EXPORT_C void
   1.338 +Tcl_SetStdChannel(channel, type)
   1.339 +    Tcl_Channel channel;
   1.340 +    int type;			/* One of TCL_STDIN, TCL_STDOUT, TCL_STDERR. */
   1.341 +{
   1.342 +    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
   1.343 +    switch (type) {
   1.344 +	case TCL_STDIN:
   1.345 +	    tsdPtr->stdinInitialized = 1;
   1.346 +	    tsdPtr->stdinChannel = channel;
   1.347 +	    break;
   1.348 +	case TCL_STDOUT:
   1.349 +	    tsdPtr->stdoutInitialized = 1;
   1.350 +	    tsdPtr->stdoutChannel = channel;
   1.351 +	    break;
   1.352 +	case TCL_STDERR:
   1.353 +	    tsdPtr->stderrInitialized = 1;
   1.354 +	    tsdPtr->stderrChannel = channel;
   1.355 +	    break;
   1.356 +    }
   1.357 +}
   1.358 +
   1.359 +/*
   1.360 + *----------------------------------------------------------------------
   1.361 + *
   1.362 + * Tcl_GetStdChannel --
   1.363 + *
   1.364 + *	Returns the specified standard channel.
   1.365 + *
   1.366 + * Results:
   1.367 + *	Returns the specified standard channel, or NULL.
   1.368 + *
   1.369 + * Side effects:
   1.370 + *	May cause the creation of a standard channel and the underlying
   1.371 + *	file.
   1.372 + *
   1.373 + *----------------------------------------------------------------------
   1.374 + */
   1.375 +EXPORT_C Tcl_Channel
   1.376 +Tcl_GetStdChannel(type)
   1.377 +    int type;			/* One of TCL_STDIN, TCL_STDOUT, TCL_STDERR. */
   1.378 +{
   1.379 +    Tcl_Channel channel = NULL;
   1.380 +    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
   1.381 +
   1.382 +    /*
   1.383 +     * If the channels were not created yet, create them now and
   1.384 +     * store them in the static variables. 
   1.385 +     */
   1.386 +
   1.387 +    switch (type) {
   1.388 +	case TCL_STDIN:
   1.389 +	    if (!tsdPtr->stdinInitialized) {
   1.390 +		tsdPtr->stdinChannel = TclpGetDefaultStdChannel(TCL_STDIN);
   1.391 +		tsdPtr->stdinInitialized = 1;
   1.392 +
   1.393 +		/*
   1.394 +                 * Artificially bump the refcount to ensure that the channel
   1.395 +                 * is only closed on exit.
   1.396 +                 *
   1.397 +                 * NOTE: Must only do this if stdinChannel is not NULL. It
   1.398 +                 * can be NULL in situations where Tcl is unable to connect
   1.399 +                 * to the standard input.
   1.400 +                 */
   1.401 +
   1.402 +                if (tsdPtr->stdinChannel != (Tcl_Channel) NULL) {
   1.403 +                    (void) Tcl_RegisterChannel((Tcl_Interp *) NULL,
   1.404 +                            tsdPtr->stdinChannel);
   1.405 +                }
   1.406 +	    }
   1.407 +	    channel = tsdPtr->stdinChannel;
   1.408 +	    break;
   1.409 +	case TCL_STDOUT:
   1.410 +	    if (!tsdPtr->stdoutInitialized) {
   1.411 +		tsdPtr->stdoutChannel = TclpGetDefaultStdChannel(TCL_STDOUT);
   1.412 +		tsdPtr->stdoutInitialized = 1;
   1.413 +                if (tsdPtr->stdoutChannel != (Tcl_Channel) NULL) {
   1.414 +                    (void) Tcl_RegisterChannel((Tcl_Interp *) NULL,
   1.415 +                            tsdPtr->stdoutChannel);
   1.416 +                }
   1.417 +	    }
   1.418 +	    channel = tsdPtr->stdoutChannel;
   1.419 +	    break;
   1.420 +	case TCL_STDERR:
   1.421 +	    if (!tsdPtr->stderrInitialized) {
   1.422 +		tsdPtr->stderrChannel = TclpGetDefaultStdChannel(TCL_STDERR);
   1.423 +		tsdPtr->stderrInitialized = 1;
   1.424 +                if (tsdPtr->stderrChannel != (Tcl_Channel) NULL) {
   1.425 +                    (void) Tcl_RegisterChannel((Tcl_Interp *) NULL,
   1.426 +                            tsdPtr->stderrChannel);
   1.427 +                }
   1.428 +	    }
   1.429 +	    channel = tsdPtr->stderrChannel;
   1.430 +	    break;
   1.431 +    }
   1.432 +    return channel;
   1.433 +}
   1.434 +
   1.435 +
   1.436 +/*
   1.437 + *----------------------------------------------------------------------
   1.438 + *
   1.439 + * Tcl_CreateCloseHandler
   1.440 + *
   1.441 + *	Creates a close callback which will be called when the channel is
   1.442 + *	closed.
   1.443 + *
   1.444 + * Results:
   1.445 + *	None.
   1.446 + *
   1.447 + * Side effects:
   1.448 + *	Causes the callback to be called in the future when the channel
   1.449 + *	will be closed.
   1.450 + *
   1.451 + *----------------------------------------------------------------------
   1.452 + */
   1.453 +
   1.454 +EXPORT_C void
   1.455 +Tcl_CreateCloseHandler(chan, proc, clientData)
   1.456 +    Tcl_Channel chan;		/* The channel for which to create the
   1.457 +                                 * close callback. */
   1.458 +    Tcl_CloseProc *proc;	/* The callback routine to call when the
   1.459 +                                 * channel will be closed. */
   1.460 +    ClientData clientData;	/* Arbitrary data to pass to the
   1.461 +                                 * close callback. */
   1.462 +{
   1.463 +    ChannelState *statePtr;
   1.464 +    CloseCallback *cbPtr;
   1.465 +
   1.466 +    statePtr = ((Channel *) chan)->state;
   1.467 +
   1.468 +    cbPtr = (CloseCallback *) ckalloc((unsigned) sizeof(CloseCallback));
   1.469 +    cbPtr->proc = proc;
   1.470 +    cbPtr->clientData = clientData;
   1.471 +
   1.472 +    cbPtr->nextPtr = statePtr->closeCbPtr;
   1.473 +    statePtr->closeCbPtr = cbPtr;
   1.474 +}
   1.475 +
   1.476 +/*
   1.477 + *----------------------------------------------------------------------
   1.478 + *
   1.479 + * Tcl_DeleteCloseHandler --
   1.480 + *
   1.481 + *	Removes a callback that would have been called on closing
   1.482 + *	the channel. If there is no matching callback then this
   1.483 + *	function has no effect.
   1.484 + *
   1.485 + * Results:
   1.486 + *	None.
   1.487 + *
   1.488 + * Side effects:
   1.489 + *	The callback will not be called in the future when the channel
   1.490 + *	is eventually closed.
   1.491 + *
   1.492 + *----------------------------------------------------------------------
   1.493 + */
   1.494 +
   1.495 +EXPORT_C void
   1.496 +Tcl_DeleteCloseHandler(chan, proc, clientData)
   1.497 +    Tcl_Channel chan;		/* The channel for which to cancel the
   1.498 +                                 * close callback. */
   1.499 +    Tcl_CloseProc *proc;	/* The procedure for the callback to
   1.500 +                                 * remove. */
   1.501 +    ClientData clientData;	/* The callback data for the callback
   1.502 +                                 * to remove. */
   1.503 +{
   1.504 +    ChannelState *statePtr;
   1.505 +    CloseCallback *cbPtr, *cbPrevPtr;
   1.506 +
   1.507 +    statePtr = ((Channel *) chan)->state;
   1.508 +    for (cbPtr = statePtr->closeCbPtr, cbPrevPtr = (CloseCallback *) NULL;
   1.509 +	 cbPtr != (CloseCallback *) NULL;
   1.510 +	 cbPtr = cbPtr->nextPtr) {
   1.511 +        if ((cbPtr->proc == proc) && (cbPtr->clientData == clientData)) {
   1.512 +            if (cbPrevPtr == (CloseCallback *) NULL) {
   1.513 +                statePtr->closeCbPtr = cbPtr->nextPtr;
   1.514 +            }
   1.515 +            ckfree((char *) cbPtr);
   1.516 +            break;
   1.517 +        } else {
   1.518 +            cbPrevPtr = cbPtr;
   1.519 +        }
   1.520 +    }
   1.521 +}
   1.522 +
   1.523 +/*
   1.524 + *----------------------------------------------------------------------
   1.525 + *
   1.526 + * GetChannelTable --
   1.527 + *
   1.528 + *	Gets and potentially initializes the channel table for an
   1.529 + *	interpreter. If it is initializing the table it also inserts
   1.530 + *	channels for stdin, stdout and stderr if the interpreter is
   1.531 + *	trusted.
   1.532 + *
   1.533 + * Results:
   1.534 + *	A pointer to the hash table created, for use by the caller.
   1.535 + *
   1.536 + * Side effects:
   1.537 + *	Initializes the channel table for an interpreter. May create
   1.538 + *	channels for stdin, stdout and stderr.
   1.539 + *
   1.540 + *----------------------------------------------------------------------
   1.541 + */
   1.542 +
   1.543 +static Tcl_HashTable *
   1.544 +GetChannelTable(interp)
   1.545 +    Tcl_Interp *interp;
   1.546 +{
   1.547 +    Tcl_HashTable *hTblPtr;	/* Hash table of channels. */
   1.548 +    Tcl_Channel stdinChan, stdoutChan, stderrChan;
   1.549 +
   1.550 +    hTblPtr = (Tcl_HashTable *) Tcl_GetAssocData(interp, "tclIO", NULL);
   1.551 +    if (hTblPtr == (Tcl_HashTable *) NULL) {
   1.552 +        hTblPtr = (Tcl_HashTable *) ckalloc((unsigned) sizeof(Tcl_HashTable));
   1.553 +        Tcl_InitHashTable(hTblPtr, TCL_STRING_KEYS);
   1.554 +
   1.555 +        (void) Tcl_SetAssocData(interp, "tclIO",
   1.556 +                (Tcl_InterpDeleteProc *) DeleteChannelTable,
   1.557 +                (ClientData) hTblPtr);
   1.558 +
   1.559 +        /*
   1.560 +         * If the interpreter is trusted (not "safe"), insert channels
   1.561 +         * for stdin, stdout and stderr (possibly creating them in the
   1.562 +         * process).
   1.563 +         */
   1.564 +
   1.565 +        if (Tcl_IsSafe(interp) == 0) {
   1.566 +            stdinChan = Tcl_GetStdChannel(TCL_STDIN);
   1.567 +            if (stdinChan != NULL) {
   1.568 +                Tcl_RegisterChannel(interp, stdinChan);
   1.569 +            }
   1.570 +            stdoutChan = Tcl_GetStdChannel(TCL_STDOUT);
   1.571 +            if (stdoutChan != NULL) {
   1.572 +                Tcl_RegisterChannel(interp, stdoutChan);
   1.573 +            }
   1.574 +            stderrChan = Tcl_GetStdChannel(TCL_STDERR);
   1.575 +            if (stderrChan != NULL) {
   1.576 +                Tcl_RegisterChannel(interp, stderrChan);
   1.577 +            }
   1.578 +        }
   1.579 +
   1.580 +    }
   1.581 +    return hTblPtr;
   1.582 +}
   1.583 +
   1.584 +/*
   1.585 + *----------------------------------------------------------------------
   1.586 + *
   1.587 + * DeleteChannelTable --
   1.588 + *
   1.589 + *	Deletes the channel table for an interpreter, closing any open
   1.590 + *	channels whose refcount reaches zero. This procedure is invoked
   1.591 + *	when an interpreter is deleted, via the AssocData cleanup
   1.592 + *	mechanism.
   1.593 + *
   1.594 + * Results:
   1.595 + *	None.
   1.596 + *
   1.597 + * Side effects:
   1.598 + *	Deletes the hash table of channels. May close channels. May flush
   1.599 + *	output on closed channels. Removes any channeEvent handlers that were
   1.600 + *	registered in this interpreter.
   1.601 + *
   1.602 + *----------------------------------------------------------------------
   1.603 + */
   1.604 +
   1.605 +static void
   1.606 +DeleteChannelTable(clientData, interp)
   1.607 +    ClientData clientData;	/* The per-interpreter data structure. */
   1.608 +    Tcl_Interp *interp;		/* The interpreter being deleted. */
   1.609 +{
   1.610 +    Tcl_HashTable *hTblPtr;	/* The hash table. */
   1.611 +    Tcl_HashSearch hSearch;	/* Search variable. */
   1.612 +    Tcl_HashEntry *hPtr;	/* Search variable. */
   1.613 +    Channel *chanPtr;		/* Channel being deleted. */
   1.614 +    ChannelState *statePtr;	/* State of Channel being deleted. */
   1.615 +    EventScriptRecord *sPtr, *prevPtr, *nextPtr;
   1.616 +    				/* Variables to loop over all channel events
   1.617 +                                 * registered, to delete the ones that refer
   1.618 +                                 * to the interpreter being deleted. */
   1.619 +
   1.620 +    /*
   1.621 +     * Delete all the registered channels - this will close channels whose
   1.622 +     * refcount reaches zero.
   1.623 +     */
   1.624 +    
   1.625 +    hTblPtr = (Tcl_HashTable *) clientData;
   1.626 +    for (hPtr = Tcl_FirstHashEntry(hTblPtr, &hSearch);
   1.627 +	 hPtr != (Tcl_HashEntry *) NULL;
   1.628 +	 hPtr = Tcl_FirstHashEntry(hTblPtr, &hSearch)) {
   1.629 +
   1.630 +        chanPtr = (Channel *) Tcl_GetHashValue(hPtr);
   1.631 +	statePtr = chanPtr->state;
   1.632 +
   1.633 +        /*
   1.634 +         * Remove any fileevents registered in this interpreter.
   1.635 +         */
   1.636 +        
   1.637 +        for (sPtr = statePtr->scriptRecordPtr,
   1.638 +                 prevPtr = (EventScriptRecord *) NULL;
   1.639 +	     sPtr != (EventScriptRecord *) NULL;
   1.640 +	     sPtr = nextPtr) {
   1.641 +            nextPtr = sPtr->nextPtr;
   1.642 +            if (sPtr->interp == interp) {
   1.643 +                if (prevPtr == (EventScriptRecord *) NULL) {
   1.644 +                    statePtr->scriptRecordPtr = nextPtr;
   1.645 +                } else {
   1.646 +                    prevPtr->nextPtr = nextPtr;
   1.647 +                }
   1.648 +
   1.649 +                Tcl_DeleteChannelHandler((Tcl_Channel) chanPtr,
   1.650 +                        TclChannelEventScriptInvoker, (ClientData) sPtr);
   1.651 +
   1.652 +		Tcl_DecrRefCount(sPtr->scriptPtr);
   1.653 +                ckfree((char *) sPtr);
   1.654 +            } else {
   1.655 +                prevPtr = sPtr;
   1.656 +            }
   1.657 +        }
   1.658 +
   1.659 +        /*
   1.660 +         * Cannot call Tcl_UnregisterChannel because that procedure calls
   1.661 +         * Tcl_GetAssocData to get the channel table, which might already
   1.662 +         * be inaccessible from the interpreter structure. Instead, we
   1.663 +         * emulate the behavior of Tcl_UnregisterChannel directly here.
   1.664 +         */
   1.665 +
   1.666 +        Tcl_DeleteHashEntry(hPtr);
   1.667 +        statePtr->refCount--;
   1.668 +        if (statePtr->refCount <= 0) {
   1.669 +            if (!(statePtr->flags & BG_FLUSH_SCHEDULED)) {
   1.670 +                (void) Tcl_Close(interp, (Tcl_Channel) chanPtr);
   1.671 +            }
   1.672 +        }
   1.673 +    }
   1.674 +    Tcl_DeleteHashTable(hTblPtr);
   1.675 +    ckfree((char *) hTblPtr);
   1.676 +}
   1.677 +
   1.678 +/*
   1.679 + *----------------------------------------------------------------------
   1.680 + *
   1.681 + * CheckForStdChannelsBeingClosed --
   1.682 + *
   1.683 + *	Perform special handling for standard channels being closed. When
   1.684 + *	given a standard channel, if the refcount is now 1, it means that
   1.685 + *	the last reference to the standard channel is being explicitly
   1.686 + *	closed. Now bump the refcount artificially down to 0, to ensure the
   1.687 + *	normal handling of channels being closed will occur. Also reset the
   1.688 + *	static pointer to the channel to NULL, to avoid dangling references.
   1.689 + *
   1.690 + * Results:
   1.691 + *	None.
   1.692 + *
   1.693 + * Side effects:
   1.694 + *	Manipulates the refcount on standard channels. May smash the global
   1.695 + *	static pointer to a standard channel.
   1.696 + *
   1.697 + *----------------------------------------------------------------------
   1.698 + */
   1.699 +
   1.700 +static void
   1.701 +CheckForStdChannelsBeingClosed(chan)
   1.702 +    Tcl_Channel chan;
   1.703 +{
   1.704 +    ChannelState *statePtr = ((Channel *) chan)->state;
   1.705 +    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
   1.706 +
   1.707 +    if ((chan == tsdPtr->stdinChannel) && (tsdPtr->stdinInitialized)) {
   1.708 +        if (statePtr->refCount < 2) {
   1.709 +            statePtr->refCount = 0;
   1.710 +            tsdPtr->stdinChannel = NULL;
   1.711 +            return;
   1.712 +        }
   1.713 +    } else if ((chan == tsdPtr->stdoutChannel)
   1.714 +	    && (tsdPtr->stdoutInitialized)) {
   1.715 +        if (statePtr->refCount < 2) {
   1.716 +            statePtr->refCount = 0;
   1.717 +            tsdPtr->stdoutChannel = NULL;
   1.718 +            return;
   1.719 +        }
   1.720 +    } else if ((chan == tsdPtr->stderrChannel)
   1.721 +	    && (tsdPtr->stderrInitialized)) {
   1.722 +        if (statePtr->refCount < 2) {
   1.723 +            statePtr->refCount = 0;
   1.724 +            tsdPtr->stderrChannel = NULL;
   1.725 +            return;
   1.726 +        }
   1.727 +    }
   1.728 +}
   1.729 +
   1.730 +/*
   1.731 + *----------------------------------------------------------------------
   1.732 + *
   1.733 + * Tcl_IsStandardChannel --
   1.734 + *
   1.735 + *	Test if the given channel is a standard channel.  No attempt
   1.736 + *	is made to check if the channel or the standard channels
   1.737 + *	are initialized or otherwise valid.
   1.738 + *
   1.739 + * Results:
   1.740 + *	Returns 1 if true, 0 if false.
   1.741 + *
   1.742 + * Side effects:
   1.743 + *      None.
   1.744 + *
   1.745 + *----------------------------------------------------------------------
   1.746 + */
   1.747 +EXPORT_C int 
   1.748 +Tcl_IsStandardChannel(chan)
   1.749 +    Tcl_Channel chan;		/* Channel to check. */
   1.750 +{
   1.751 +    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
   1.752 +
   1.753 +    if ((chan == tsdPtr->stdinChannel) 
   1.754 +	|| (chan == tsdPtr->stdoutChannel)
   1.755 +	|| (chan == tsdPtr->stderrChannel)) {
   1.756 +	return 1;
   1.757 +    } else {
   1.758 +	return 0;
   1.759 +    }
   1.760 +}
   1.761 +
   1.762 +/*
   1.763 + *----------------------------------------------------------------------
   1.764 + *
   1.765 + * Tcl_RegisterChannel --
   1.766 + *
   1.767 + *	Adds an already-open channel to the channel table of an interpreter.
   1.768 + *	If the interpreter passed as argument is NULL, it only increments
   1.769 + *	the channel refCount.
   1.770 + *
   1.771 + * Results:
   1.772 + *	None.
   1.773 + *
   1.774 + * Side effects:
   1.775 + *	May increment the reference count of a channel.
   1.776 + *
   1.777 + *----------------------------------------------------------------------
   1.778 + */
   1.779 +
   1.780 +EXPORT_C void
   1.781 +Tcl_RegisterChannel(interp, chan)
   1.782 +    Tcl_Interp *interp;		/* Interpreter in which to add the channel. */
   1.783 +    Tcl_Channel chan;		/* The channel to add to this interpreter
   1.784 +                                 * channel table. */
   1.785 +{
   1.786 +    Tcl_HashTable *hTblPtr;	/* Hash table of channels. */
   1.787 +    Tcl_HashEntry *hPtr;	/* Search variable. */
   1.788 +    int new;			/* Is the hash entry new or does it exist? */
   1.789 +    Channel *chanPtr;		/* The actual channel. */
   1.790 +    ChannelState *statePtr;	/* State of the actual channel. */
   1.791 +
   1.792 +    /*
   1.793 +     * Always (un)register bottom-most channel in the stack.  This makes
   1.794 +     * management of the channel list easier because no manipulation is
   1.795 +     * necessary during (un)stack operation.
   1.796 +     */
   1.797 +    chanPtr = ((Channel *) chan)->state->bottomChanPtr;
   1.798 +    statePtr = chanPtr->state;
   1.799 +
   1.800 +    if (statePtr->channelName == (CONST char *) NULL) {
   1.801 +        panic("Tcl_RegisterChannel: channel without name");
   1.802 +    }
   1.803 +    if (interp != (Tcl_Interp *) NULL) {
   1.804 +        hTblPtr = GetChannelTable(interp);
   1.805 +        hPtr = Tcl_CreateHashEntry(hTblPtr, statePtr->channelName, &new);
   1.806 +        if (new == 0) {
   1.807 +            if (chan == (Tcl_Channel) Tcl_GetHashValue(hPtr)) {
   1.808 +                return;
   1.809 +            }
   1.810 +
   1.811 +	    panic("Tcl_RegisterChannel: duplicate channel names");
   1.812 +        }
   1.813 +        Tcl_SetHashValue(hPtr, (ClientData) chanPtr);
   1.814 +    }
   1.815 +
   1.816 +    statePtr->refCount++;
   1.817 +}
   1.818 +
   1.819 +/*
   1.820 + *----------------------------------------------------------------------
   1.821 + *
   1.822 + * Tcl_UnregisterChannel --
   1.823 + *
   1.824 + *	Deletes the hash entry for a channel associated with an interpreter.
   1.825 + *	If the interpreter given as argument is NULL, it only decrements the
   1.826 + *	reference count.  (This all happens in the Tcl_DetachChannel helper
   1.827 + *	function).
   1.828 + *	
   1.829 + *	Finally, if the reference count of the channel drops to zero,
   1.830 + *	it is deleted.
   1.831 + *
   1.832 + * Results:
   1.833 + *	A standard Tcl result.
   1.834 + *
   1.835 + * Side effects:
   1.836 + *	Calls Tcl_DetachChannel which deletes the hash entry for a channel 
   1.837 + *	associated with an interpreter.
   1.838 + *	
   1.839 + *	May delete the channel, which can have a variety of consequences,
   1.840 + *	especially if we are forced to close the channel.
   1.841 + *
   1.842 + *----------------------------------------------------------------------
   1.843 + */
   1.844 +
   1.845 +EXPORT_C int
   1.846 +Tcl_UnregisterChannel(interp, chan)
   1.847 +    Tcl_Interp *interp;		/* Interpreter in which channel is defined. */
   1.848 +    Tcl_Channel chan;		/* Channel to delete. */
   1.849 +{
   1.850 +    ChannelState *statePtr;	/* State of the real channel. */
   1.851 +
   1.852 +    statePtr = ((Channel *) chan)->state->bottomChanPtr->state;
   1.853 + 
   1.854 +    if (statePtr->flags & CHANNEL_INCLOSE) {
   1.855 +        if (interp != (Tcl_Interp*) NULL) {
   1.856 +	    Tcl_AppendResult(interp, 
   1.857 +	     "Illegal recursive call to close through close-handler of channel",
   1.858 +	     (char *) NULL);
   1.859 +	}
   1.860 +        return TCL_ERROR;
   1.861 +    }
   1.862 + 
   1.863 +    if (DetachChannel(interp, chan) != TCL_OK) {
   1.864 +        return TCL_OK;
   1.865 +    }
   1.866 +    
   1.867 +    statePtr = ((Channel *) chan)->state->bottomChanPtr->state;
   1.868 +
   1.869 +    /*
   1.870 +     * Perform special handling for standard channels being closed. If the
   1.871 +     * refCount is now 1 it means that the last reference to the standard
   1.872 +     * channel is being explicitly closed, so bump the refCount down
   1.873 +     * artificially to 0. This will ensure that the channel is actually
   1.874 +     * closed, below. Also set the static pointer to NULL for the channel.
   1.875 +     */
   1.876 +
   1.877 +    CheckForStdChannelsBeingClosed(chan);
   1.878 +
   1.879 +    /*
   1.880 +     * If the refCount reached zero, close the actual channel.
   1.881 +     */
   1.882 +
   1.883 +    if (statePtr->refCount <= 0) {
   1.884 +
   1.885 +        /*
   1.886 +         * Ensure that if there is another buffer, it gets flushed
   1.887 +         * whether or not we are doing a background flush.
   1.888 +         */
   1.889 +
   1.890 +        if ((statePtr->curOutPtr != NULL) &&
   1.891 +                (statePtr->curOutPtr->nextAdded >
   1.892 +                        statePtr->curOutPtr->nextRemoved)) {
   1.893 +            statePtr->flags |= BUFFER_READY;
   1.894 +        }
   1.895 +	Tcl_Preserve((ClientData)statePtr);
   1.896 +        if (!(statePtr->flags & BG_FLUSH_SCHEDULED)) {
   1.897 +	    /* We don't want to re-enter Tcl_Close */
   1.898 +	    if (!(statePtr->flags & CHANNEL_CLOSED)) {
   1.899 +		if (Tcl_Close(interp, chan) != TCL_OK) {
   1.900 +		    statePtr->flags |= CHANNEL_CLOSED;
   1.901 +		    Tcl_Release((ClientData)statePtr);
   1.902 +		    return TCL_ERROR;
   1.903 +		}
   1.904 +	    }
   1.905 +        }
   1.906 +        statePtr->flags |= CHANNEL_CLOSED;
   1.907 +	Tcl_Release((ClientData)statePtr);
   1.908 +    }
   1.909 +    return TCL_OK;
   1.910 +}
   1.911 +
   1.912 +/*
   1.913 + *----------------------------------------------------------------------
   1.914 + *
   1.915 + * Tcl_DetachChannel --
   1.916 + *
   1.917 + *	Deletes the hash entry for a channel associated with an interpreter.
   1.918 + *	If the interpreter given as argument is NULL, it only decrements the
   1.919 + *	reference count.  Even if the ref count drops to zero, the 
   1.920 + *	channel is NOT closed or cleaned up.  This allows a channel to
   1.921 + *	be detached from an interpreter and left in the same state it
   1.922 + *	was in when it was originally returned by 'Tcl_OpenFileChannel',
   1.923 + *	for example.
   1.924 + *	
   1.925 + *	This function cannot be used on the standard channels, and
   1.926 + *	will return TCL_ERROR if that is attempted.
   1.927 + *	
   1.928 + *	This function should only be necessary for special purposes
   1.929 + *	in which you need to generate a pristine channel from one
   1.930 + *	that has already been used.  All ordinary purposes will almost
   1.931 + *	always want to use Tcl_UnregisterChannel instead.
   1.932 + *	
   1.933 + *	Provided the channel is not attached to any other interpreter,
   1.934 + *	it can then be closed with Tcl_Close, rather than with 
   1.935 + *	Tcl_UnregisterChannel.
   1.936 + *
   1.937 + * Results:
   1.938 + *	A standard Tcl result.  If the channel is not currently registered
   1.939 + *	with the given interpreter, TCL_ERROR is returned, otherwise
   1.940 + *	TCL_OK.  However no error messages are left in the interp's result.
   1.941 + *
   1.942 + * Side effects:
   1.943 + *	Deletes the hash entry for a channel associated with an 
   1.944 + *	interpreter.
   1.945 + *
   1.946 + *----------------------------------------------------------------------
   1.947 + */
   1.948 +
   1.949 +EXPORT_C int
   1.950 +Tcl_DetachChannel(interp, chan)
   1.951 +    Tcl_Interp *interp;		/* Interpreter in which channel is defined. */
   1.952 +    Tcl_Channel chan;		/* Channel to delete. */
   1.953 +{
   1.954 +    if (Tcl_IsStandardChannel(chan)) {
   1.955 +        return TCL_ERROR;
   1.956 +    }
   1.957 +    
   1.958 +    return DetachChannel(interp, chan);
   1.959 +}
   1.960 +
   1.961 +/*
   1.962 + *----------------------------------------------------------------------
   1.963 + *
   1.964 + * DetachChannel --
   1.965 + *
   1.966 + *	Deletes the hash entry for a channel associated with an interpreter.
   1.967 + *	If the interpreter given as argument is NULL, it only decrements the
   1.968 + *	reference count.  Even if the ref count drops to zero, the 
   1.969 + *	channel is NOT closed or cleaned up.  This allows a channel to
   1.970 + *	be detached from an interpreter and left in the same state it
   1.971 + *	was in when it was originally returned by 'Tcl_OpenFileChannel',
   1.972 + *	for example.
   1.973 + *
   1.974 + * Results:
   1.975 + *	A standard Tcl result.  If the channel is not currently registered
   1.976 + *	with the given interpreter, TCL_ERROR is returned, otherwise
   1.977 + *	TCL_OK.  However no error messages are left in the interp's result.
   1.978 + *
   1.979 + * Side effects:
   1.980 + *	Deletes the hash entry for a channel associated with an 
   1.981 + *	interpreter.
   1.982 + *
   1.983 + *----------------------------------------------------------------------
   1.984 + */
   1.985 +
   1.986 +static int
   1.987 +DetachChannel(interp, chan)
   1.988 +    Tcl_Interp *interp;		/* Interpreter in which channel is defined. */
   1.989 +    Tcl_Channel chan;		/* Channel to delete. */
   1.990 +{
   1.991 +    Tcl_HashTable *hTblPtr;	/* Hash table of channels. */
   1.992 +    Tcl_HashEntry *hPtr;	/* Search variable. */
   1.993 +    Channel *chanPtr;		/* The real IO channel. */
   1.994 +    ChannelState *statePtr;	/* State of the real channel. */
   1.995 +
   1.996 +    /*
   1.997 +     * Always (un)register bottom-most channel in the stack.  This makes
   1.998 +     * management of the channel list easier because no manipulation is
   1.999 +     * necessary during (un)stack operation.
  1.1000 +     */
  1.1001 +    chanPtr = ((Channel *) chan)->state->bottomChanPtr;
  1.1002 +    statePtr = chanPtr->state;
  1.1003 +
  1.1004 +    if (interp != (Tcl_Interp *) NULL) {
  1.1005 +	hTblPtr = (Tcl_HashTable *) Tcl_GetAssocData(interp, "tclIO", NULL);
  1.1006 +	if (hTblPtr == (Tcl_HashTable *) NULL) {
  1.1007 +	    return TCL_ERROR;
  1.1008 +	}
  1.1009 +	hPtr = Tcl_FindHashEntry(hTblPtr, statePtr->channelName);
  1.1010 +	if (hPtr == (Tcl_HashEntry *) NULL) {
  1.1011 +	    return TCL_ERROR;
  1.1012 +	}
  1.1013 +	if ((Channel *) Tcl_GetHashValue(hPtr) != chanPtr) {
  1.1014 +	    return TCL_ERROR;
  1.1015 +	}
  1.1016 +	Tcl_DeleteHashEntry(hPtr);
  1.1017 +
  1.1018 +	/*
  1.1019 +	 * Remove channel handlers that refer to this interpreter, so that they
  1.1020 +	 * will not be present if the actual close is delayed and more events
  1.1021 +	 * happen on the channel. This may occur if the channel is shared
  1.1022 +	 * between several interpreters, or if the channel has async
  1.1023 +	 * flushing active.
  1.1024 +	 */
  1.1025 +    
  1.1026 +	CleanupChannelHandlers(interp, chanPtr);
  1.1027 +    }
  1.1028 +
  1.1029 +    statePtr->refCount--;
  1.1030 +    
  1.1031 +    return TCL_OK;
  1.1032 +}
  1.1033 +
  1.1034 +
  1.1035 +/*
  1.1036 + *---------------------------------------------------------------------------
  1.1037 + *
  1.1038 + * Tcl_GetChannel --
  1.1039 + *
  1.1040 + *	Finds an existing Tcl_Channel structure by name in a given
  1.1041 + *	interpreter. This function is public because it is used by
  1.1042 + *	channel-type-specific functions.
  1.1043 + *
  1.1044 + * Results:
  1.1045 + *	A Tcl_Channel or NULL on failure. If failed, interp's result
  1.1046 + *	object contains an error message.  *modePtr is filled with the
  1.1047 + *	modes in which the channel was opened.
  1.1048 + *
  1.1049 + * Side effects:
  1.1050 + *	None.
  1.1051 + *
  1.1052 + *---------------------------------------------------------------------------
  1.1053 + */
  1.1054 +
  1.1055 +EXPORT_C Tcl_Channel
  1.1056 +Tcl_GetChannel(interp, chanName, modePtr)
  1.1057 +    Tcl_Interp *interp;		/* Interpreter in which to find or create
  1.1058 +                                 * the channel. */
  1.1059 +    CONST char *chanName;	/* The name of the channel. */
  1.1060 +    int *modePtr;		/* Where to store the mode in which the
  1.1061 +                                 * channel was opened? Will contain an ORed
  1.1062 +                                 * combination of TCL_READABLE and
  1.1063 +                                 * TCL_WRITABLE, if non-NULL. */
  1.1064 +{
  1.1065 +    Channel *chanPtr;		/* The actual channel. */
  1.1066 +    Tcl_HashTable *hTblPtr;	/* Hash table of channels. */
  1.1067 +    Tcl_HashEntry *hPtr;	/* Search variable. */
  1.1068 +    CONST char *name;		/* Translated name. */
  1.1069 +
  1.1070 +    /*
  1.1071 +     * Substitute "stdin", etc.  Note that even though we immediately
  1.1072 +     * find the channel using Tcl_GetStdChannel, we still need to look
  1.1073 +     * it up in the specified interpreter to ensure that it is present
  1.1074 +     * in the channel table.  Otherwise, safe interpreters would always
  1.1075 +     * have access to the standard channels.
  1.1076 +     */
  1.1077 +
  1.1078 +    name = chanName;
  1.1079 +    if ((chanName[0] == 's') && (chanName[1] == 't')) {
  1.1080 +	chanPtr = NULL;
  1.1081 +	if (strcmp(chanName, "stdin") == 0) {
  1.1082 +	    chanPtr = (Channel *) Tcl_GetStdChannel(TCL_STDIN);
  1.1083 +	} else if (strcmp(chanName, "stdout") == 0) {
  1.1084 +	    chanPtr = (Channel *) Tcl_GetStdChannel(TCL_STDOUT);
  1.1085 +	} else if (strcmp(chanName, "stderr") == 0) {
  1.1086 +	    chanPtr = (Channel *) Tcl_GetStdChannel(TCL_STDERR);
  1.1087 +	}
  1.1088 +	if (chanPtr != NULL) {
  1.1089 +	    name = chanPtr->state->channelName;
  1.1090 +	}
  1.1091 +    }
  1.1092 +
  1.1093 +    hTblPtr = GetChannelTable(interp);
  1.1094 +    hPtr = Tcl_FindHashEntry(hTblPtr, name);
  1.1095 +    if (hPtr == (Tcl_HashEntry *) NULL) {
  1.1096 +        Tcl_AppendResult(interp, "can not find channel named \"",
  1.1097 +                chanName, "\"", (char *) NULL);
  1.1098 +        return NULL;
  1.1099 +    }
  1.1100 +
  1.1101 +    /*
  1.1102 +     * Always return bottom-most channel in the stack.  This one lives
  1.1103 +     * the longest - other channels may go away unnoticed.
  1.1104 +     * The other APIs compensate where necessary to retrieve the
  1.1105 +     * topmost channel again.
  1.1106 +     */
  1.1107 +    chanPtr = (Channel *) Tcl_GetHashValue(hPtr);
  1.1108 +    chanPtr = chanPtr->state->bottomChanPtr;
  1.1109 +    if (modePtr != NULL) {
  1.1110 +        *modePtr = (chanPtr->state->flags & (TCL_READABLE|TCL_WRITABLE));
  1.1111 +    }
  1.1112 +    
  1.1113 +    return (Tcl_Channel) chanPtr;
  1.1114 +}
  1.1115 +
  1.1116 +/*
  1.1117 + *----------------------------------------------------------------------
  1.1118 + *
  1.1119 + * Tcl_CreateChannel --
  1.1120 + *
  1.1121 + *	Creates a new entry in the hash table for a Tcl_Channel
  1.1122 + *	record.
  1.1123 + *
  1.1124 + * Results:
  1.1125 + *	Returns the new Tcl_Channel.
  1.1126 + *
  1.1127 + * Side effects:
  1.1128 + *	Creates a new Tcl_Channel instance and inserts it into the
  1.1129 + *	hash table.
  1.1130 + *
  1.1131 + *----------------------------------------------------------------------
  1.1132 + */
  1.1133 +
  1.1134 +EXPORT_C Tcl_Channel
  1.1135 +Tcl_CreateChannel(typePtr, chanName, instanceData, mask)
  1.1136 +    Tcl_ChannelType *typePtr;	/* The channel type record. */
  1.1137 +    CONST char *chanName;	/* Name of channel to record. */
  1.1138 +    ClientData instanceData;	/* Instance specific data. */
  1.1139 +    int mask;			/* TCL_READABLE & TCL_WRITABLE to indicate
  1.1140 +                                 * if the channel is readable, writable. */
  1.1141 +{
  1.1142 +    Channel *chanPtr;		/* The channel structure newly created. */
  1.1143 +    ChannelState *statePtr;	/* The stack-level independent state info
  1.1144 +				 * for the channel. */
  1.1145 +    CONST char *name;
  1.1146 +    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
  1.1147 +
  1.1148 +    /*
  1.1149 +     * With the change of the Tcl_ChannelType structure to use a version in
  1.1150 +     * 8.3.2+, we have to make sure that our assumption that the structure
  1.1151 +     * remains a binary compatible size is true.
  1.1152 +     *
  1.1153 +     * If this assertion fails on some system, then it can be removed
  1.1154 +     * only if the user recompiles code with older channel drivers in
  1.1155 +     * the new system as well.
  1.1156 +     */
  1.1157 +
  1.1158 +    assert(sizeof(Tcl_ChannelTypeVersion) == sizeof(Tcl_DriverBlockModeProc*));
  1.1159 +
  1.1160 +    /*
  1.1161 +     * JH: We could subsequently memset these to 0 to avoid the
  1.1162 +     * numerous assignments to 0/NULL below.
  1.1163 +     */
  1.1164 +    chanPtr  = (Channel *) ckalloc((unsigned) sizeof(Channel));
  1.1165 +    statePtr = (ChannelState *) ckalloc((unsigned) sizeof(ChannelState));
  1.1166 +    chanPtr->state = statePtr;
  1.1167 +
  1.1168 +    chanPtr->instanceData	= instanceData;
  1.1169 +    chanPtr->typePtr		= typePtr;
  1.1170 +
  1.1171 +    /*
  1.1172 +     * Set all the bits that are part of the stack-independent state
  1.1173 +     * information for the channel.
  1.1174 +     */
  1.1175 +
  1.1176 +    if (chanName != (char *) NULL) {
  1.1177 +	char *tmp = ckalloc((unsigned) (strlen(chanName) + 1));
  1.1178 +        statePtr->channelName = tmp;
  1.1179 +        strcpy(tmp, chanName);
  1.1180 +    } else {
  1.1181 +        panic("Tcl_CreateChannel: NULL channel name");
  1.1182 +    }
  1.1183 +
  1.1184 +    statePtr->flags		= mask;
  1.1185 +
  1.1186 +    /*
  1.1187 +     * Set the channel to system default encoding.
  1.1188 +     */
  1.1189 +
  1.1190 +    statePtr->encoding = NULL;
  1.1191 +    name = Tcl_GetEncodingName(NULL);
  1.1192 +    if (strcmp(name, "binary") != 0) {
  1.1193 +    	statePtr->encoding = Tcl_GetEncoding(NULL, name);
  1.1194 +    }
  1.1195 +    statePtr->inputEncodingState	= NULL;
  1.1196 +    statePtr->inputEncodingFlags	= TCL_ENCODING_START;
  1.1197 +    statePtr->outputEncodingState	= NULL;
  1.1198 +    statePtr->outputEncodingFlags	= TCL_ENCODING_START;
  1.1199 +
  1.1200 +    /*
  1.1201 +     * Set the channel up initially in AUTO input translation mode to
  1.1202 +     * accept "\n", "\r" and "\r\n". Output translation mode is set to
  1.1203 +     * a platform specific default value. The eofChar is set to 0 for both
  1.1204 +     * input and output, so that Tcl does not look for an in-file EOF
  1.1205 +     * indicator (e.g. ^Z) and does not append an EOF indicator to files.
  1.1206 +     */
  1.1207 +
  1.1208 +    statePtr->inputTranslation	= TCL_TRANSLATE_AUTO;
  1.1209 +    statePtr->outputTranslation	= TCL_PLATFORM_TRANSLATION;
  1.1210 +    statePtr->inEofChar		= 0;
  1.1211 +    statePtr->outEofChar	= 0;
  1.1212 +
  1.1213 +    statePtr->unreportedError	= 0;
  1.1214 +    statePtr->refCount		= 0;
  1.1215 +    statePtr->closeCbPtr	= (CloseCallback *) NULL;
  1.1216 +    statePtr->curOutPtr		= (ChannelBuffer *) NULL;
  1.1217 +    statePtr->outQueueHead	= (ChannelBuffer *) NULL;
  1.1218 +    statePtr->outQueueTail	= (ChannelBuffer *) NULL;
  1.1219 +    statePtr->saveInBufPtr	= (ChannelBuffer *) NULL;
  1.1220 +    statePtr->inQueueHead	= (ChannelBuffer *) NULL;
  1.1221 +    statePtr->inQueueTail	= (ChannelBuffer *) NULL;
  1.1222 +    statePtr->chPtr		= (ChannelHandler *) NULL;
  1.1223 +    statePtr->interestMask	= 0;
  1.1224 +    statePtr->scriptRecordPtr	= (EventScriptRecord *) NULL;
  1.1225 +    statePtr->bufSize		= CHANNELBUFFER_DEFAULT_SIZE;
  1.1226 +    statePtr->timer		= NULL;
  1.1227 +    statePtr->csPtr		= NULL;
  1.1228 +
  1.1229 +    statePtr->outputStage	= NULL;
  1.1230 +    if ((statePtr->encoding != NULL) && (statePtr->flags & TCL_WRITABLE)) {
  1.1231 +	statePtr->outputStage = (char *)
  1.1232 +	    ckalloc((unsigned) (statePtr->bufSize + 2));
  1.1233 +    }
  1.1234 +
  1.1235 +    /*
  1.1236 +     * As we are creating the channel, it is obviously the top for now
  1.1237 +     */
  1.1238 +    statePtr->topChanPtr	= chanPtr;
  1.1239 +    statePtr->bottomChanPtr	= chanPtr;
  1.1240 +    chanPtr->downChanPtr	= (Channel *) NULL;
  1.1241 +    chanPtr->upChanPtr		= (Channel *) NULL;
  1.1242 +    chanPtr->inQueueHead        = (ChannelBuffer*) NULL;
  1.1243 +    chanPtr->inQueueTail        = (ChannelBuffer*) NULL;
  1.1244 +
  1.1245 +    /*
  1.1246 +     * Link the channel into the list of all channels; create an on-exit
  1.1247 +     * handler if there is not one already, to close off all the channels
  1.1248 +     * in the list on exit.
  1.1249 +     *
  1.1250 +     * JH: Could call Tcl_SpliceChannel, but need to avoid NULL check.
  1.1251 +     *
  1.1252 +     * TIP #218.
  1.1253 +     * AK: Just initialize the field to NULL before invoking Tcl_SpliceChannel
  1.1254 +     *     We need Tcl_SpliceChannel, for the threadAction calls.
  1.1255 +     *     There is no real reason to duplicate all of this.
  1.1256 +     * NOTE: All drivers using thread actions now have to perform their TSD
  1.1257 +     *       manipulation only in their thread action proc. Doing it when
  1.1258 +     *       creating their instance structures will collide with the thread
  1.1259 +     *       action activity and lead to damaged lists.
  1.1260 +     */
  1.1261 +
  1.1262 +    statePtr->nextCSPtr = (ChannelState *) NULL;
  1.1263 +    Tcl_SpliceChannel ((Tcl_Channel) chanPtr);
  1.1264 +
  1.1265 +    /*
  1.1266 +     * Install this channel in the first empty standard channel slot, if
  1.1267 +     * the channel was previously closed explicitly.
  1.1268 +     */
  1.1269 +#if TCL_INHERIT_STD_CHANNELS
  1.1270 +    if ((tsdPtr->stdinChannel == NULL) &&
  1.1271 +	    (tsdPtr->stdinInitialized == 1)) {
  1.1272 +	Tcl_SetStdChannel((Tcl_Channel) chanPtr, TCL_STDIN);
  1.1273 +        Tcl_RegisterChannel((Tcl_Interp *) NULL, (Tcl_Channel) chanPtr);
  1.1274 +    } else if ((tsdPtr->stdoutChannel == NULL) &&
  1.1275 +	    (tsdPtr->stdoutInitialized == 1)) {
  1.1276 +	Tcl_SetStdChannel((Tcl_Channel) chanPtr, TCL_STDOUT);
  1.1277 +        Tcl_RegisterChannel((Tcl_Interp *) NULL, (Tcl_Channel) chanPtr);
  1.1278 +    } else if ((tsdPtr->stderrChannel == NULL) &&
  1.1279 +	    (tsdPtr->stderrInitialized == 1)) {
  1.1280 +	Tcl_SetStdChannel((Tcl_Channel) chanPtr, TCL_STDERR);
  1.1281 +        Tcl_RegisterChannel((Tcl_Interp *) NULL, (Tcl_Channel) chanPtr);
  1.1282 +    }
  1.1283 +#endif
  1.1284 +    return (Tcl_Channel) chanPtr;
  1.1285 +}
  1.1286 +
  1.1287 +/*
  1.1288 + *----------------------------------------------------------------------
  1.1289 + *
  1.1290 + * Tcl_StackChannel --
  1.1291 + *
  1.1292 + *	Replaces an entry in the hash table for a Tcl_Channel
  1.1293 + *	record. The replacement is a new channel with same name,
  1.1294 + *	it supercedes the replaced channel. Input and output of
  1.1295 + *	the superceded channel is now going through the newly
  1.1296 + *	created channel and allows the arbitrary filtering/manipulation
  1.1297 + *	of the dataflow.
  1.1298 + *
  1.1299 + *	Andreas Kupries <a.kupries@westend.com>, 12/13/1998
  1.1300 + *	"Trf-Patch for filtering channels"
  1.1301 + *
  1.1302 + * Results:
  1.1303 + *	Returns the new Tcl_Channel, which actually contains the
  1.1304 + *      saved information about prevChan.
  1.1305 + *
  1.1306 + * Side effects:
  1.1307 + *    A new channel structure is allocated and linked below
  1.1308 + *    the existing channel.  The channel operations and client
  1.1309 + *    data of the existing channel are copied down to the newly
  1.1310 + *    created channel, and the current channel has its operations
  1.1311 + *    replaced by the new typePtr.
  1.1312 + *
  1.1313 + *----------------------------------------------------------------------
  1.1314 + */
  1.1315 +
  1.1316 +EXPORT_C Tcl_Channel
  1.1317 +Tcl_StackChannel(interp, typePtr, instanceData, mask, prevChan)
  1.1318 +    Tcl_Interp	    *interp;	   /* The interpreter we are working in */
  1.1319 +    Tcl_ChannelType *typePtr;	   /* The channel type record for the new
  1.1320 +				    * channel. */
  1.1321 +    ClientData	     instanceData; /* Instance specific data for the new
  1.1322 +				    * channel. */
  1.1323 +    int		     mask;	   /* TCL_READABLE & TCL_WRITABLE to indicate
  1.1324 +				    * if the channel is readable, writable. */
  1.1325 +    Tcl_Channel	     prevChan;	   /* The channel structure to replace */
  1.1326 +{
  1.1327 +    ThreadSpecificData	*tsdPtr = TCL_TSD_INIT(&dataKey);
  1.1328 +    Channel		*chanPtr, *prevChanPtr;
  1.1329 +    ChannelState	*statePtr;
  1.1330 +
  1.1331 +    /*
  1.1332 +     * Find the given channel in the list of all channels.
  1.1333 +     * If we don't find it, then it was never registered correctly.
  1.1334 +     *
  1.1335 +     * This operation should occur at the top of a channel stack.
  1.1336 +     */
  1.1337 +
  1.1338 +    statePtr    = (ChannelState *) tsdPtr->firstCSPtr;
  1.1339 +    prevChanPtr = ((Channel *) prevChan)->state->topChanPtr;
  1.1340 +
  1.1341 +    while ((statePtr != NULL) && (statePtr->topChanPtr != prevChanPtr)) {
  1.1342 +	statePtr = statePtr->nextCSPtr;
  1.1343 +    }
  1.1344 +
  1.1345 +    if (statePtr == NULL) {
  1.1346 +	if (interp) {
  1.1347 +	    Tcl_AppendResult(interp, "couldn't find state for channel \"",
  1.1348 +		    Tcl_GetChannelName(prevChan), "\"", (char *) NULL);
  1.1349 +	}
  1.1350 +        return (Tcl_Channel) NULL;
  1.1351 +    }
  1.1352 +
  1.1353 +    /*
  1.1354 +     * Here we check if the given "mask" matches the "flags"
  1.1355 +     * of the already existing channel.
  1.1356 +     *
  1.1357 +     *	  | - | R | W | RW |
  1.1358 +     *	--+---+---+---+----+	<=>  0 != (chan->mask & prevChan->mask)
  1.1359 +     *	- |   |   |   |    |
  1.1360 +     *	R |   | + |   | +  |	The superceding channel is allowed to
  1.1361 +     *	W |   |   | + | +  |	restrict the capabilities of the
  1.1362 +     *	RW|   | + | + | +  |	superceded one !
  1.1363 +     *	--+---+---+---+----+
  1.1364 +     */
  1.1365 +
  1.1366 +    if ((mask & (statePtr->flags & (TCL_READABLE | TCL_WRITABLE))) == 0) {
  1.1367 +	if (interp) {
  1.1368 +	    Tcl_AppendResult(interp,
  1.1369 +		    "reading and writing both disallowed for channel \"",
  1.1370 +		    Tcl_GetChannelName(prevChan), "\"", (char *) NULL);
  1.1371 +	}
  1.1372 +        return (Tcl_Channel) NULL;
  1.1373 +    }
  1.1374 +
  1.1375 +    /*
  1.1376 +     * Flush the buffers. This ensures that any data still in them
  1.1377 +     * at this time is not handled by the new transformation. Restrict
  1.1378 +     * this to writable channels. Take care to hide a possible bg-copy
  1.1379 +     * in progress from Tcl_Flush and the CheckForChannelErrors inside.
  1.1380 +     */
  1.1381 +
  1.1382 +    if ((mask & TCL_WRITABLE) != 0) {
  1.1383 +        CopyState *csPtr;
  1.1384 +
  1.1385 +        csPtr           = statePtr->csPtr;
  1.1386 +	statePtr->csPtr = (CopyState*) NULL;
  1.1387 +
  1.1388 +	if (Tcl_Flush((Tcl_Channel) prevChanPtr) != TCL_OK) {
  1.1389 +	    statePtr->csPtr = csPtr;
  1.1390 +	    if (interp) {
  1.1391 +		Tcl_AppendResult(interp, "could not flush channel \"",
  1.1392 +			Tcl_GetChannelName(prevChan), "\"", (char *) NULL);
  1.1393 +	    }
  1.1394 +	    return (Tcl_Channel) NULL;
  1.1395 +	}
  1.1396 +
  1.1397 +	statePtr->csPtr = csPtr;
  1.1398 +    }
  1.1399 +    /*
  1.1400 +     * Discard any input in the buffers. They are not yet read by the
  1.1401 +     * user of the channel, so they have to go through the new
  1.1402 +     * transformation before reading. As the buffers contain the
  1.1403 +     * untransformed form their contents are not only useless but actually
  1.1404 +     * distorts our view of the system.
  1.1405 +     *
  1.1406 +     * To preserve the information without having to read them again and
  1.1407 +     * to avoid problems with the location in the channel (seeking might
  1.1408 +     * be impossible) we move the buffers from the common state structure
  1.1409 +     * into the channel itself. We use the buffers in the channel below
  1.1410 +     * the new transformation to hold the data. In the future this allows
  1.1411 +     * us to write transformations which pre-read data and push the unused
  1.1412 +     * part back when they are going away.
  1.1413 +     */
  1.1414 +
  1.1415 +    if (((mask & TCL_READABLE) != 0) &&
  1.1416 +	(statePtr->inQueueHead != (ChannelBuffer*) NULL)) {
  1.1417 +      /*
  1.1418 +       * Remark: It is possible that the channel buffers contain data from
  1.1419 +       * some earlier push-backs.
  1.1420 +       */
  1.1421 +
  1.1422 +      statePtr->inQueueTail->nextPtr = prevChanPtr->inQueueHead;
  1.1423 +      prevChanPtr->inQueueHead       = statePtr->inQueueHead;
  1.1424 +
  1.1425 +      if (prevChanPtr->inQueueTail == (ChannelBuffer*) NULL) {
  1.1426 +	prevChanPtr->inQueueTail = statePtr->inQueueTail;
  1.1427 +      }
  1.1428 +
  1.1429 +      statePtr->inQueueHead          = (ChannelBuffer*) NULL;
  1.1430 +      statePtr->inQueueTail          = (ChannelBuffer*) NULL;
  1.1431 +    }
  1.1432 +
  1.1433 +    chanPtr = (Channel *) ckalloc((unsigned) sizeof(Channel));
  1.1434 +
  1.1435 +    /*
  1.1436 +     * Save some of the current state into the new structure,
  1.1437 +     * reinitialize the parts which will stay with the transformation.
  1.1438 +     *
  1.1439 +     * Remarks:
  1.1440 +     */
  1.1441 +
  1.1442 +    chanPtr->state		= statePtr;
  1.1443 +    chanPtr->instanceData	= instanceData;
  1.1444 +    chanPtr->typePtr		= typePtr;
  1.1445 +    chanPtr->downChanPtr	= prevChanPtr;
  1.1446 +    chanPtr->upChanPtr		= (Channel *) NULL;
  1.1447 +    chanPtr->inQueueHead        = (ChannelBuffer*) NULL;
  1.1448 +    chanPtr->inQueueTail        = (ChannelBuffer*) NULL;
  1.1449 +
  1.1450 +    /*
  1.1451 +     * Place new block at the head of a possibly existing list of previously
  1.1452 +     * stacked channels.
  1.1453 +     */
  1.1454 +
  1.1455 +    prevChanPtr->upChanPtr	= chanPtr;
  1.1456 +    statePtr->topChanPtr	= chanPtr;
  1.1457 +
  1.1458 +    return (Tcl_Channel) chanPtr;
  1.1459 +}
  1.1460 +
  1.1461 +/*
  1.1462 + *----------------------------------------------------------------------
  1.1463 + *
  1.1464 + * Tcl_UnstackChannel --
  1.1465 + *
  1.1466 + *	Unstacks an entry in the hash table for a Tcl_Channel
  1.1467 + *	record. This is the reverse to 'Tcl_StackChannel'.
  1.1468 + *
  1.1469 + * Results:
  1.1470 + *	A standard Tcl result.
  1.1471 + *
  1.1472 + * Side effects:
  1.1473 + *	If TCL_ERROR is returned, the posix error code will be set
  1.1474 + *	with Tcl_SetErrno.
  1.1475 + *
  1.1476 + *----------------------------------------------------------------------
  1.1477 + */
  1.1478 +
  1.1479 +EXPORT_C int
  1.1480 +Tcl_UnstackChannel (interp, chan)
  1.1481 +    Tcl_Interp *interp; /* The interpreter we are working in */
  1.1482 +    Tcl_Channel chan;   /* The channel to unstack */
  1.1483 +{
  1.1484 +    Channel      *chanPtr  = (Channel *) chan;
  1.1485 +    ChannelState *statePtr = chanPtr->state;
  1.1486 +    int result = 0;
  1.1487 +
  1.1488 +    /*
  1.1489 +     * This operation should occur at the top of a channel stack.
  1.1490 +     */
  1.1491 +
  1.1492 +    chanPtr = statePtr->topChanPtr;
  1.1493 +
  1.1494 +    if (chanPtr->downChanPtr != (Channel *) NULL) {
  1.1495 +        /*
  1.1496 +	 * Instead of manipulating the per-thread / per-interp list/hashtable
  1.1497 +	 * of registered channels we wind down the state of the transformation,
  1.1498 +	 * and then restore the state of underlying channel into the old
  1.1499 +	 * structure.
  1.1500 +	 */
  1.1501 +	Channel *downChanPtr = chanPtr->downChanPtr;
  1.1502 +
  1.1503 +	/*
  1.1504 +	 * Flush the buffers. This ensures that any data still in them
  1.1505 +	 * at this time _is_ handled by the transformation we are unstacking
  1.1506 +	 * right now. Restrict this to writable channels. Take care to hide
  1.1507 +	 * a possible bg-copy in progress from Tcl_Flush and the
  1.1508 +	 * CheckForChannelErrors inside.
  1.1509 +	 */
  1.1510 +
  1.1511 +	if (statePtr->flags & TCL_WRITABLE) {
  1.1512 +	    CopyState*    csPtr;
  1.1513 +
  1.1514 +	    csPtr           = statePtr->csPtr;
  1.1515 +	    statePtr->csPtr = (CopyState*) NULL;
  1.1516 +
  1.1517 +	    if (Tcl_Flush((Tcl_Channel) chanPtr) != TCL_OK) {
  1.1518 +	        statePtr->csPtr = csPtr;
  1.1519 +		if (interp) {
  1.1520 +		    Tcl_AppendResult(interp, "could not flush channel \"",
  1.1521 +			    Tcl_GetChannelName((Tcl_Channel) chanPtr), "\"",
  1.1522 +			    (char *) NULL);
  1.1523 +		}
  1.1524 +		return TCL_ERROR;
  1.1525 +	    }
  1.1526 +
  1.1527 +	    statePtr->csPtr = csPtr;
  1.1528 +	}
  1.1529 +
  1.1530 +	/*
  1.1531 +	 * Anything in the input queue and the push-back buffers of
  1.1532 +	 * the transformation going away is transformed data, but not
  1.1533 +	 * yet read. As unstacking means that the caller does not want
  1.1534 +	 * to see transformed data any more we have to discard these
  1.1535 +	 * bytes. To avoid writing an analogue to 'DiscardInputQueued'
  1.1536 +	 * we move the information in the push back buffers to the
  1.1537 +	 * input queue and then call 'DiscardInputQueued' on that.
  1.1538 +	 */
  1.1539 +
  1.1540 +	if (((statePtr->flags & TCL_READABLE)  != 0) &&
  1.1541 +	    ((statePtr->inQueueHead != (ChannelBuffer*) NULL) ||
  1.1542 +	     (chanPtr->inQueueHead  != (ChannelBuffer*) NULL))) {
  1.1543 +
  1.1544 +	    if ((statePtr->inQueueHead != (ChannelBuffer*) NULL) &&
  1.1545 +		(chanPtr->inQueueHead  != (ChannelBuffer*) NULL)) {
  1.1546 +	        statePtr->inQueueTail->nextPtr = chanPtr->inQueueHead;
  1.1547 +		statePtr->inQueueTail = chanPtr->inQueueTail;
  1.1548 +	        statePtr->inQueueHead = statePtr->inQueueTail;
  1.1549 +
  1.1550 +	    } else if (chanPtr->inQueueHead != (ChannelBuffer*) NULL) {
  1.1551 +	        statePtr->inQueueHead = chanPtr->inQueueHead;
  1.1552 +		statePtr->inQueueTail = chanPtr->inQueueTail;
  1.1553 +	    }
  1.1554 +
  1.1555 +	    chanPtr->inQueueHead          = (ChannelBuffer*) NULL;
  1.1556 +	    chanPtr->inQueueTail          = (ChannelBuffer*) NULL;
  1.1557 +
  1.1558 +	    DiscardInputQueued (statePtr, 0);
  1.1559 +	}
  1.1560 +
  1.1561 +	statePtr->topChanPtr	= downChanPtr;
  1.1562 +	downChanPtr->upChanPtr	= (Channel *) NULL;
  1.1563 +
  1.1564 +	/*
  1.1565 +	 * Leave this link intact for closeproc
  1.1566 +	 *  chanPtr->downChanPtr	= (Channel *) NULL;
  1.1567 +	 */
  1.1568 +
  1.1569 +	/*
  1.1570 +	 * Close and free the channel driver state.
  1.1571 +	 */
  1.1572 +
  1.1573 +	if (chanPtr->typePtr->closeProc != TCL_CLOSE2PROC) {
  1.1574 +	    result = (chanPtr->typePtr->closeProc)(chanPtr->instanceData,
  1.1575 +		    interp);
  1.1576 +	} else {
  1.1577 +	    result = (chanPtr->typePtr->close2Proc)(chanPtr->instanceData,
  1.1578 +		    interp, 0);
  1.1579 +	}
  1.1580 +
  1.1581 +	chanPtr->typePtr	= NULL;
  1.1582 +	/*
  1.1583 +	 * AK: Tcl_NotifyChannel may hold a reference to this block of memory
  1.1584 +	 */
  1.1585 +	Tcl_EventuallyFree((ClientData) chanPtr, TCL_DYNAMIC);
  1.1586 +	UpdateInterest(downChanPtr);
  1.1587 +
  1.1588 +	if (result != 0) {
  1.1589 +	    Tcl_SetErrno(result);
  1.1590 +	    return TCL_ERROR;
  1.1591 +	}
  1.1592 +    } else {
  1.1593 +        /*
  1.1594 +	 * This channel does not cover another one.
  1.1595 +	 * Simply do a close, if necessary.
  1.1596 +	 */
  1.1597 +
  1.1598 +        if (statePtr->refCount <= 0) {
  1.1599 +            if (Tcl_Close(interp, chan) != TCL_OK) {
  1.1600 +                return TCL_ERROR;
  1.1601 +            }
  1.1602 +	}
  1.1603 +    }
  1.1604 +
  1.1605 +    return TCL_OK;
  1.1606 +}
  1.1607 +
  1.1608 +/*
  1.1609 + *----------------------------------------------------------------------
  1.1610 + *
  1.1611 + * Tcl_GetStackedChannel --
  1.1612 + *
  1.1613 + *	Determines whether the specified channel is stacked upon another.
  1.1614 + *
  1.1615 + * Results:
  1.1616 + *	NULL if the channel is not stacked upon another one, or a reference
  1.1617 + *	to the channel it is stacked upon. This reference can be used in
  1.1618 + *	queries, but modification is not allowed.
  1.1619 + *
  1.1620 + * Side effects:
  1.1621 + *	None.
  1.1622 + *
  1.1623 + *----------------------------------------------------------------------
  1.1624 + */
  1.1625 +
  1.1626 +EXPORT_C Tcl_Channel
  1.1627 +Tcl_GetStackedChannel(chan)
  1.1628 +    Tcl_Channel chan;
  1.1629 +{
  1.1630 +    Channel *chanPtr = (Channel *) chan;	/* The actual channel. */
  1.1631 +
  1.1632 +    return (Tcl_Channel) chanPtr->downChanPtr;
  1.1633 +}
  1.1634 +
  1.1635 +/*
  1.1636 + *----------------------------------------------------------------------
  1.1637 + *
  1.1638 + * Tcl_GetTopChannel --
  1.1639 + *
  1.1640 + *	Returns the top channel of a channel stack.
  1.1641 + *
  1.1642 + * Results:
  1.1643 + *	NULL if the channel is not stacked upon another one, or a reference
  1.1644 + *	to the channel it is stacked upon. This reference can be used in
  1.1645 + *	queries, but modification is not allowed.
  1.1646 + *
  1.1647 + * Side effects:
  1.1648 + *	None.
  1.1649 + *
  1.1650 + *----------------------------------------------------------------------
  1.1651 + */
  1.1652 +
  1.1653 +EXPORT_C Tcl_Channel
  1.1654 +Tcl_GetTopChannel(chan)
  1.1655 +    Tcl_Channel chan;
  1.1656 +{
  1.1657 +    Channel *chanPtr = (Channel *) chan;	/* The actual channel. */
  1.1658 +
  1.1659 +    return (Tcl_Channel) chanPtr->state->topChanPtr;
  1.1660 +}
  1.1661 +
  1.1662 +/*
  1.1663 + *----------------------------------------------------------------------
  1.1664 + *
  1.1665 + * Tcl_GetChannelInstanceData --
  1.1666 + *
  1.1667 + *	Returns the client data associated with a channel.
  1.1668 + *
  1.1669 + * Results:
  1.1670 + *	The client data.
  1.1671 + *
  1.1672 + * Side effects:
  1.1673 + *	None.
  1.1674 + *
  1.1675 + *----------------------------------------------------------------------
  1.1676 + */
  1.1677 +
  1.1678 +EXPORT_C ClientData
  1.1679 +Tcl_GetChannelInstanceData(chan)
  1.1680 +    Tcl_Channel chan;		/* Channel for which to return client data. */
  1.1681 +{
  1.1682 +    Channel *chanPtr = (Channel *) chan;	/* The actual channel. */
  1.1683 +
  1.1684 +    return chanPtr->instanceData;
  1.1685 +}
  1.1686 +
  1.1687 +/*
  1.1688 + *----------------------------------------------------------------------
  1.1689 + *
  1.1690 + * Tcl_GetChannelThread --
  1.1691 + *
  1.1692 + *	Given a channel structure, returns the thread managing it.
  1.1693 + *	TIP #10
  1.1694 + *
  1.1695 + * Results:
  1.1696 + *	Returns the id of the thread managing the channel.
  1.1697 + *
  1.1698 + * Side effects:
  1.1699 + *	None.
  1.1700 + *
  1.1701 + *----------------------------------------------------------------------
  1.1702 + */
  1.1703 +
  1.1704 +EXPORT_C Tcl_ThreadId
  1.1705 +Tcl_GetChannelThread(chan)
  1.1706 +    Tcl_Channel chan;		/* The channel to return managing thread for. */
  1.1707 +{
  1.1708 +    Channel *chanPtr = (Channel *) chan;	/* The actual channel. */
  1.1709 +
  1.1710 +    return chanPtr->state->managingThread;
  1.1711 +}
  1.1712 +
  1.1713 +/*
  1.1714 + *----------------------------------------------------------------------
  1.1715 + *
  1.1716 + * Tcl_GetChannelType --
  1.1717 + *
  1.1718 + *	Given a channel structure, returns the channel type structure.
  1.1719 + *
  1.1720 + * Results:
  1.1721 + *	Returns a pointer to the channel type structure.
  1.1722 + *
  1.1723 + * Side effects:
  1.1724 + *	None.
  1.1725 + *
  1.1726 + *----------------------------------------------------------------------
  1.1727 + */
  1.1728 +
  1.1729 +EXPORT_C Tcl_ChannelType *
  1.1730 +Tcl_GetChannelType(chan)
  1.1731 +    Tcl_Channel chan;		/* The channel to return type for. */
  1.1732 +{
  1.1733 +    Channel *chanPtr = (Channel *) chan;	/* The actual channel. */
  1.1734 +
  1.1735 +    return chanPtr->typePtr;
  1.1736 +}
  1.1737 +
  1.1738 +/*
  1.1739 + *----------------------------------------------------------------------
  1.1740 + *
  1.1741 + * Tcl_GetChannelMode --
  1.1742 + *
  1.1743 + *	Computes a mask indicating whether the channel is open for
  1.1744 + *	reading and writing.
  1.1745 + *
  1.1746 + * Results:
  1.1747 + *	An OR-ed combination of TCL_READABLE and TCL_WRITABLE.
  1.1748 + *
  1.1749 + * Side effects:
  1.1750 + *	None.
  1.1751 + *
  1.1752 + *----------------------------------------------------------------------
  1.1753 + */
  1.1754 +
  1.1755 +EXPORT_C int
  1.1756 +Tcl_GetChannelMode(chan)
  1.1757 +    Tcl_Channel chan;		/* The channel for which the mode is
  1.1758 +                                 * being computed. */
  1.1759 +{
  1.1760 +    ChannelState *statePtr = ((Channel *) chan)->state;
  1.1761 +					/* State of actual channel. */
  1.1762 +
  1.1763 +    return (statePtr->flags & (TCL_READABLE | TCL_WRITABLE));
  1.1764 +}
  1.1765 +
  1.1766 +/*
  1.1767 + *----------------------------------------------------------------------
  1.1768 + *
  1.1769 + * Tcl_GetChannelName --
  1.1770 + *
  1.1771 + *	Returns the string identifying the channel name.
  1.1772 + *
  1.1773 + * Results:
  1.1774 + *	The string containing the channel name. This memory is
  1.1775 + *	owned by the generic layer and should not be modified by
  1.1776 + *	the caller.
  1.1777 + *
  1.1778 + * Side effects:
  1.1779 + *	None.
  1.1780 + *
  1.1781 + *----------------------------------------------------------------------
  1.1782 + */
  1.1783 +
  1.1784 +EXPORT_C CONST char *
  1.1785 +Tcl_GetChannelName(chan)
  1.1786 +    Tcl_Channel chan;		/* The channel for which to return the name. */
  1.1787 +{
  1.1788 +    ChannelState *statePtr;	/* State of actual channel. */
  1.1789 +
  1.1790 +    statePtr = ((Channel *) chan)->state;
  1.1791 +    return statePtr->channelName;
  1.1792 +}
  1.1793 +
  1.1794 +/*
  1.1795 + *----------------------------------------------------------------------
  1.1796 + *
  1.1797 + * Tcl_GetChannelHandle --
  1.1798 + *
  1.1799 + *	Returns an OS handle associated with a channel.
  1.1800 + *
  1.1801 + * Results:
  1.1802 + *	Returns TCL_OK and places the handle in handlePtr, or returns
  1.1803 + *	TCL_ERROR on failure.
  1.1804 + *
  1.1805 + * Side effects:
  1.1806 + *	None.
  1.1807 + *
  1.1808 + *----------------------------------------------------------------------
  1.1809 + */
  1.1810 +
  1.1811 +EXPORT_C int
  1.1812 +Tcl_GetChannelHandle(chan, direction, handlePtr)
  1.1813 +    Tcl_Channel chan;		/* The channel to get file from. */
  1.1814 +    int direction;		/* TCL_WRITABLE or TCL_READABLE. */
  1.1815 +    ClientData *handlePtr;	/* Where to store handle */
  1.1816 +{
  1.1817 +    Channel *chanPtr;		/* The actual channel. */
  1.1818 +    ClientData handle;
  1.1819 +    int result;
  1.1820 +
  1.1821 +    chanPtr = ((Channel *) chan)->state->bottomChanPtr;
  1.1822 +    result = (chanPtr->typePtr->getHandleProc)(chanPtr->instanceData,
  1.1823 +	    direction, &handle);
  1.1824 +    if (handlePtr) {
  1.1825 +	*handlePtr = handle;
  1.1826 +    }
  1.1827 +    return result;
  1.1828 +}
  1.1829 +
  1.1830 +/*
  1.1831 + *---------------------------------------------------------------------------
  1.1832 + *
  1.1833 + * AllocChannelBuffer --
  1.1834 + *
  1.1835 + *	A channel buffer has BUFFER_PADDING bytes extra at beginning to
  1.1836 + *	hold any bytes of a native-encoding character that got split by
  1.1837 + *	the end of the previous buffer and need to be moved to the
  1.1838 + *	beginning of the next buffer to make a contiguous string so it
  1.1839 + *	can be converted to UTF-8.
  1.1840 + *
  1.1841 + *	A channel buffer has BUFFER_PADDING bytes extra at the end to
  1.1842 + *	hold any bytes of a native-encoding character (generated from a
  1.1843 + *	UTF-8 character) that overflow past the end of the buffer and
  1.1844 + *	need to be moved to the next buffer.
  1.1845 + *
  1.1846 + * Results:
  1.1847 + *	A newly allocated channel buffer.
  1.1848 + *
  1.1849 + * Side effects:
  1.1850 + *	None.
  1.1851 + *
  1.1852 + *---------------------------------------------------------------------------
  1.1853 + */
  1.1854 +
  1.1855 +static ChannelBuffer *
  1.1856 +AllocChannelBuffer(length)
  1.1857 +    int length;			/* Desired length of channel buffer. */
  1.1858 +{
  1.1859 +    ChannelBuffer *bufPtr;
  1.1860 +    int n;
  1.1861 +
  1.1862 +    n = length + CHANNELBUFFER_HEADER_SIZE + BUFFER_PADDING + BUFFER_PADDING;
  1.1863 +    bufPtr = (ChannelBuffer *) ckalloc((unsigned) n);
  1.1864 +    bufPtr->nextAdded	= BUFFER_PADDING;
  1.1865 +    bufPtr->nextRemoved	= BUFFER_PADDING;
  1.1866 +    bufPtr->bufLength	= length + BUFFER_PADDING;
  1.1867 +    bufPtr->nextPtr	= (ChannelBuffer *) NULL;
  1.1868 +    return bufPtr;
  1.1869 +}
  1.1870 +
  1.1871 +/*
  1.1872 + *----------------------------------------------------------------------
  1.1873 + *
  1.1874 + * RecycleBuffer --
  1.1875 + *
  1.1876 + *	Helper function to recycle input and output buffers. Ensures
  1.1877 + *	that two input buffers are saved (one in the input queue and
  1.1878 + *	another in the saveInBufPtr field) and that curOutPtr is set
  1.1879 + *	to a buffer. Only if these conditions are met is the buffer
  1.1880 + *	freed to the OS.
  1.1881 + *
  1.1882 + * Results:
  1.1883 + *	None.
  1.1884 + *
  1.1885 + * Side effects:
  1.1886 + *	May free a buffer to the OS.
  1.1887 + *
  1.1888 + *----------------------------------------------------------------------
  1.1889 + */
  1.1890 +
  1.1891 +static void
  1.1892 +RecycleBuffer(statePtr, bufPtr, mustDiscard)
  1.1893 +    ChannelState *statePtr;	/* ChannelState in which to recycle buffers. */
  1.1894 +    ChannelBuffer *bufPtr;	/* The buffer to recycle. */
  1.1895 +    int mustDiscard;		/* If nonzero, free the buffer to the
  1.1896 +                                 * OS, always. */
  1.1897 +{
  1.1898 +    /*
  1.1899 +     * Do we have to free the buffer to the OS?
  1.1900 +     */
  1.1901 +
  1.1902 +    if (mustDiscard) {
  1.1903 +        ckfree((char *) bufPtr);
  1.1904 +        return;
  1.1905 +    }
  1.1906 +
  1.1907 +    /*
  1.1908 +     * Only save buffers which are at least as big as the requested
  1.1909 +     * buffersize for the channel. This is to honor dynamic changes
  1.1910 +     * of the buffersize made by the user.
  1.1911 +     */
  1.1912 +
  1.1913 +    if ((bufPtr->bufLength - BUFFER_PADDING) < statePtr->bufSize) {
  1.1914 +        ckfree((char *) bufPtr);
  1.1915 +        return;
  1.1916 +    }
  1.1917 +
  1.1918 +    /*
  1.1919 +     * Only save buffers for the input queue if the channel is readable.
  1.1920 +     */
  1.1921 +    
  1.1922 +    if (statePtr->flags & TCL_READABLE) {
  1.1923 +        if (statePtr->inQueueHead == (ChannelBuffer *) NULL) {
  1.1924 +            statePtr->inQueueHead = bufPtr;
  1.1925 +            statePtr->inQueueTail = bufPtr;
  1.1926 +            goto keepit;
  1.1927 +        }
  1.1928 +        if (statePtr->saveInBufPtr == (ChannelBuffer *) NULL) {
  1.1929 +            statePtr->saveInBufPtr = bufPtr;
  1.1930 +            goto keepit;
  1.1931 +        }
  1.1932 +    }
  1.1933 +
  1.1934 +    /*
  1.1935 +     * Only save buffers for the output queue if the channel is writable.
  1.1936 +     */
  1.1937 +
  1.1938 +    if (statePtr->flags & TCL_WRITABLE) {
  1.1939 +        if (statePtr->curOutPtr == (ChannelBuffer *) NULL) {
  1.1940 +            statePtr->curOutPtr = bufPtr;
  1.1941 +            goto keepit;
  1.1942 +        }
  1.1943 +    }
  1.1944 +
  1.1945 +    /*
  1.1946 +     * If we reached this code we return the buffer to the OS.
  1.1947 +     */
  1.1948 +
  1.1949 +    ckfree((char *) bufPtr);
  1.1950 +    return;
  1.1951 +
  1.1952 +    keepit:
  1.1953 +    bufPtr->nextRemoved = BUFFER_PADDING;
  1.1954 +    bufPtr->nextAdded = BUFFER_PADDING;
  1.1955 +    bufPtr->nextPtr = (ChannelBuffer *) NULL;
  1.1956 +}
  1.1957 +
  1.1958 +/*
  1.1959 + *----------------------------------------------------------------------
  1.1960 + *
  1.1961 + * DiscardOutputQueued --
  1.1962 + *
  1.1963 + *	Discards all output queued in the output queue of a channel.
  1.1964 + *
  1.1965 + * Results:
  1.1966 + *	None.
  1.1967 + *
  1.1968 + * Side effects:
  1.1969 + *	Recycles buffers.
  1.1970 + *
  1.1971 + *----------------------------------------------------------------------
  1.1972 + */
  1.1973 +
  1.1974 +static void
  1.1975 +DiscardOutputQueued(statePtr)
  1.1976 +    ChannelState *statePtr;	/* ChannelState for which to discard output. */
  1.1977 +{
  1.1978 +    ChannelBuffer *bufPtr;
  1.1979 +    
  1.1980 +    while (statePtr->outQueueHead != (ChannelBuffer *) NULL) {
  1.1981 +        bufPtr = statePtr->outQueueHead;
  1.1982 +        statePtr->outQueueHead = bufPtr->nextPtr;
  1.1983 +        RecycleBuffer(statePtr, bufPtr, 0);
  1.1984 +    }
  1.1985 +    statePtr->outQueueHead = (ChannelBuffer *) NULL;
  1.1986 +    statePtr->outQueueTail = (ChannelBuffer *) NULL;
  1.1987 +}
  1.1988 +
  1.1989 +/*
  1.1990 + *----------------------------------------------------------------------
  1.1991 + *
  1.1992 + * CheckForDeadChannel --
  1.1993 + *
  1.1994 + *	This function checks is a given channel is Dead.
  1.1995 + *      (A channel that has been closed but not yet deallocated.)
  1.1996 + *
  1.1997 + * Results:
  1.1998 + *	True (1) if channel is Dead, False (0) if channel is Ok
  1.1999 + *
  1.2000 + * Side effects:
  1.2001 + *      None
  1.2002 + *
  1.2003 + *----------------------------------------------------------------------
  1.2004 + */
  1.2005 +
  1.2006 +static int
  1.2007 +CheckForDeadChannel(interp, statePtr)
  1.2008 +    Tcl_Interp *interp;		/* For error reporting (can be NULL) */
  1.2009 +    ChannelState *statePtr;	/* The channel state to check. */
  1.2010 +{
  1.2011 +    if (statePtr->flags & CHANNEL_DEAD) {
  1.2012 +        Tcl_SetErrno(EINVAL);
  1.2013 +	if (interp) {
  1.2014 +	    Tcl_AppendResult(interp,
  1.2015 +		    "unable to access channel: invalid channel",
  1.2016 +		    (char *) NULL);   
  1.2017 +	}
  1.2018 +	return 1;
  1.2019 +    }
  1.2020 +    return 0;
  1.2021 +}
  1.2022 +
  1.2023 +/*
  1.2024 + *----------------------------------------------------------------------
  1.2025 + *
  1.2026 + * FlushChannel --
  1.2027 + *
  1.2028 + *	This function flushes as much of the queued output as is possible
  1.2029 + *	now. If calledFromAsyncFlush is nonzero, it is being called in an
  1.2030 + *	event handler to flush channel output asynchronously.
  1.2031 + *
  1.2032 + * Results:
  1.2033 + *	0 if successful, else the error code that was returned by the
  1.2034 + *	channel type operation.
  1.2035 + *
  1.2036 + * Side effects:
  1.2037 + *	May produce output on a channel. May block indefinitely if the
  1.2038 + *	channel is synchronous. May schedule an async flush on the channel.
  1.2039 + *	May recycle memory for buffers in the output queue.
  1.2040 + *
  1.2041 + *----------------------------------------------------------------------
  1.2042 + */
  1.2043 +
  1.2044 +static int
  1.2045 +FlushChannel(interp, chanPtr, calledFromAsyncFlush)
  1.2046 +    Tcl_Interp *interp;			/* For error reporting during close. */
  1.2047 +    Channel *chanPtr;			/* The channel to flush on. */
  1.2048 +    int calledFromAsyncFlush;		/* If nonzero then we are being
  1.2049 +                                         * called from an asynchronous
  1.2050 +                                         * flush callback. */
  1.2051 +{
  1.2052 +    ChannelState *statePtr = chanPtr->state;
  1.2053 +					/* State of the channel stack. */
  1.2054 +    ChannelBuffer *bufPtr;		/* Iterates over buffered output
  1.2055 +                                         * queue. */
  1.2056 +    int toWrite;			/* Amount of output data in current
  1.2057 +                                         * buffer available to be written. */
  1.2058 +    int written;			/* Amount of output data actually
  1.2059 +                                         * written in current round. */
  1.2060 +    int errorCode = 0;			/* Stores POSIX error codes from
  1.2061 +                                         * channel driver operations. */
  1.2062 +    int wroteSome = 0;			/* Set to one if any data was
  1.2063 +					 * written to the driver. */
  1.2064 +
  1.2065 +    /*
  1.2066 +     * Prevent writing on a dead channel -- a channel that has been closed
  1.2067 +     * but not yet deallocated. This can occur if the exit handler for the
  1.2068 +     * channel deallocation runs before all channels are deregistered in
  1.2069 +     * all interpreters.
  1.2070 +     */
  1.2071 +    
  1.2072 +    if (CheckForDeadChannel(interp, statePtr)) return -1;
  1.2073 +    
  1.2074 +    /*
  1.2075 +     * Loop over the queued buffers and attempt to flush as
  1.2076 +     * much as possible of the queued output to the channel.
  1.2077 +     */
  1.2078 +
  1.2079 +    while (1) {
  1.2080 +
  1.2081 +        /*
  1.2082 +         * If the queue is empty and there is a ready current buffer, OR if
  1.2083 +         * the current buffer is full, then move the current buffer to the
  1.2084 +         * queue.
  1.2085 +         */
  1.2086 +
  1.2087 +        if (((statePtr->curOutPtr != (ChannelBuffer *) NULL) &&
  1.2088 +                (statePtr->curOutPtr->nextAdded == statePtr->curOutPtr->bufLength))
  1.2089 +                || ((statePtr->flags & BUFFER_READY) &&
  1.2090 +                        (statePtr->outQueueHead == (ChannelBuffer *) NULL))) {
  1.2091 +            statePtr->flags &= (~(BUFFER_READY));
  1.2092 +            statePtr->curOutPtr->nextPtr = (ChannelBuffer *) NULL;
  1.2093 +            if (statePtr->outQueueHead == (ChannelBuffer *) NULL) {
  1.2094 +                statePtr->outQueueHead = statePtr->curOutPtr;
  1.2095 +            } else {
  1.2096 +                statePtr->outQueueTail->nextPtr = statePtr->curOutPtr;
  1.2097 +            }
  1.2098 +            statePtr->outQueueTail = statePtr->curOutPtr;
  1.2099 +            statePtr->curOutPtr = (ChannelBuffer *) NULL;
  1.2100 +        }
  1.2101 +        bufPtr = statePtr->outQueueHead;
  1.2102 +
  1.2103 +        /*
  1.2104 +         * If we are not being called from an async flush and an async
  1.2105 +         * flush is active, we just return without producing any output.
  1.2106 +         */
  1.2107 +
  1.2108 +        if ((!calledFromAsyncFlush) &&
  1.2109 +                (statePtr->flags & BG_FLUSH_SCHEDULED)) {
  1.2110 +            return 0;
  1.2111 +        }
  1.2112 +
  1.2113 +        /*
  1.2114 +         * If the output queue is still empty, break out of the while loop.
  1.2115 +         */
  1.2116 +
  1.2117 +        if (bufPtr == (ChannelBuffer *) NULL) {
  1.2118 +            break;	/* Out of the "while (1)". */
  1.2119 +        }
  1.2120 +
  1.2121 +        /*
  1.2122 +         * Produce the output on the channel.
  1.2123 +         */
  1.2124 +
  1.2125 +        toWrite = bufPtr->nextAdded - bufPtr->nextRemoved;
  1.2126 +        written = (chanPtr->typePtr->outputProc) (chanPtr->instanceData,
  1.2127 +                bufPtr->buf + bufPtr->nextRemoved, toWrite,
  1.2128 +		&errorCode);
  1.2129 +
  1.2130 +	/*
  1.2131 +         * If the write failed completely attempt to start the asynchronous
  1.2132 +         * flush mechanism and break out of this loop - do not attempt to
  1.2133 +         * write any more output at this time.
  1.2134 +         */
  1.2135 +
  1.2136 +        if (written < 0) {
  1.2137 +            
  1.2138 +            /*
  1.2139 +             * If the last attempt to write was interrupted, simply retry.
  1.2140 +             */
  1.2141 +            
  1.2142 +            if (errorCode == EINTR) {
  1.2143 +                errorCode = 0;
  1.2144 +                continue;
  1.2145 +            }
  1.2146 +
  1.2147 +            /*
  1.2148 +             * If the channel is non-blocking and we would have blocked,
  1.2149 +             * start a background flushing handler and break out of the loop.
  1.2150 +             */
  1.2151 +
  1.2152 +            if ((errorCode == EWOULDBLOCK) || (errorCode == EAGAIN)) {
  1.2153 +		/*
  1.2154 +		 * This used to check for CHANNEL_NONBLOCKING, and panic
  1.2155 +		 * if the channel was blocking.  However, it appears
  1.2156 +		 * that setting stdin to -blocking 0 has some effect on
  1.2157 +		 * the stdout when it's a tty channel (dup'ed underneath)
  1.2158 +		 */
  1.2159 +		if (!(statePtr->flags & BG_FLUSH_SCHEDULED)) {
  1.2160 +		    statePtr->flags |= BG_FLUSH_SCHEDULED;
  1.2161 +		    UpdateInterest(chanPtr);
  1.2162 +		}
  1.2163 +		errorCode = 0;
  1.2164 +		break;
  1.2165 +            }
  1.2166 +
  1.2167 +            /*
  1.2168 +             * Decide whether to report the error upwards or defer it.
  1.2169 +             */
  1.2170 +
  1.2171 +            if (calledFromAsyncFlush) {
  1.2172 +                if (statePtr->unreportedError == 0) {
  1.2173 +                    statePtr->unreportedError = errorCode;
  1.2174 +                }
  1.2175 +            } else {
  1.2176 +                Tcl_SetErrno(errorCode);
  1.2177 +		if (interp != NULL) {
  1.2178 +
  1.2179 +		    /*
  1.2180 +		     * Casting away CONST here is safe because the
  1.2181 +		     * TCL_VOLATILE flag guarantees CONST treatment
  1.2182 +		     * of the Posix error string.
  1.2183 +		     */
  1.2184 +
  1.2185 +		    Tcl_SetResult(interp,
  1.2186 +			    (char *) Tcl_PosixError(interp), TCL_VOLATILE);
  1.2187 +		}
  1.2188 +            }
  1.2189 +
  1.2190 +            /*
  1.2191 +             * When we get an error we throw away all the output
  1.2192 +             * currently queued.
  1.2193 +             */
  1.2194 +
  1.2195 +            DiscardOutputQueued(statePtr);
  1.2196 +            continue;
  1.2197 +        } else {
  1.2198 +	    wroteSome = 1;
  1.2199 +	}
  1.2200 +
  1.2201 +        bufPtr->nextRemoved += written;
  1.2202 +
  1.2203 +        /*
  1.2204 +         * If this buffer is now empty, recycle it.
  1.2205 +         */
  1.2206 +
  1.2207 +        if (bufPtr->nextRemoved == bufPtr->nextAdded) {
  1.2208 +            statePtr->outQueueHead = bufPtr->nextPtr;
  1.2209 +            if (statePtr->outQueueHead == (ChannelBuffer *) NULL) {
  1.2210 +                statePtr->outQueueTail = (ChannelBuffer *) NULL;
  1.2211 +            }
  1.2212 +            RecycleBuffer(statePtr, bufPtr, 0);
  1.2213 +        }
  1.2214 +    }	/* Closes "while (1)". */
  1.2215 +
  1.2216 +    /*
  1.2217 +     * If we wrote some data while flushing in the background, we are done.
  1.2218 +     * We can't finish the background flush until we run out of data and
  1.2219 +     * the channel becomes writable again.  This ensures that all of the
  1.2220 +     * pending data has been flushed at the system level.
  1.2221 +     */
  1.2222 +
  1.2223 +    if (statePtr->flags & BG_FLUSH_SCHEDULED) {
  1.2224 +	if (wroteSome) {
  1.2225 +	    return errorCode;
  1.2226 +	} else if (statePtr->outQueueHead == (ChannelBuffer *) NULL) {
  1.2227 +	    statePtr->flags &= (~(BG_FLUSH_SCHEDULED));
  1.2228 +	    (chanPtr->typePtr->watchProc)(chanPtr->instanceData,
  1.2229 +		    statePtr->interestMask);
  1.2230 +	}
  1.2231 +    }
  1.2232 +
  1.2233 +    /*
  1.2234 +     * If the channel is flagged as closed, delete it when the refCount
  1.2235 +     * drops to zero, the output queue is empty and there is no output
  1.2236 +     * in the current output buffer.
  1.2237 +     */
  1.2238 +
  1.2239 +    if ((statePtr->flags & CHANNEL_CLOSED) && (statePtr->refCount <= 0) &&
  1.2240 +            (statePtr->outQueueHead == (ChannelBuffer *) NULL) &&
  1.2241 +            ((statePtr->curOutPtr == (ChannelBuffer *) NULL) ||
  1.2242 +                    (statePtr->curOutPtr->nextAdded ==
  1.2243 +                            statePtr->curOutPtr->nextRemoved))) {
  1.2244 +	return CloseChannel(interp, chanPtr, errorCode);
  1.2245 +    }
  1.2246 +    return errorCode;
  1.2247 +}
  1.2248 +
  1.2249 +/*
  1.2250 + *----------------------------------------------------------------------
  1.2251 + *
  1.2252 + * CloseChannel --
  1.2253 + *
  1.2254 + *	Utility procedure to close a channel and free associated resources.
  1.2255 + *
  1.2256 + *	If the channel was stacked, then the it will copy the necessary
  1.2257 + *	elements of the NEXT channel into the TOP channel, in essence
  1.2258 + *	unstacking the channel.  The NEXT channel will then be freed.
  1.2259 + *
  1.2260 + *	If the channel was not stacked, then we will free all the bits
  1.2261 + *	for the TOP channel, including the data structure itself.
  1.2262 + *
  1.2263 + * Results:
  1.2264 + *	1 if the channel was stacked, 0 otherwise.
  1.2265 + *
  1.2266 + * Side effects:
  1.2267 + *	May close the actual channel; may free memory.
  1.2268 + *	May change the value of errno.
  1.2269 + *
  1.2270 + *----------------------------------------------------------------------
  1.2271 + */
  1.2272 +
  1.2273 +static int
  1.2274 +CloseChannel(interp, chanPtr, errorCode)
  1.2275 +    Tcl_Interp *interp;			/* For error reporting. */
  1.2276 +    Channel *chanPtr;			/* The channel to close. */
  1.2277 +    int errorCode;			/* Status of operation so far. */
  1.2278 +{
  1.2279 +    int result = 0;			/* Of calling driver close
  1.2280 +                                         * operation. */
  1.2281 +    ChannelState *statePtr;		/* state of the channel stack. */
  1.2282 +    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
  1.2283 +
  1.2284 +    if (chanPtr == NULL) {
  1.2285 +        return result;
  1.2286 +    }
  1.2287 +    statePtr = chanPtr->state;
  1.2288 +
  1.2289 +    /*
  1.2290 +     * No more input can be consumed so discard any leftover input.
  1.2291 +     */
  1.2292 +
  1.2293 +    DiscardInputQueued(statePtr, 1);
  1.2294 +
  1.2295 +    /*
  1.2296 +     * Discard a leftover buffer in the current output buffer field.
  1.2297 +     */
  1.2298 +
  1.2299 +    if (statePtr->curOutPtr != (ChannelBuffer *) NULL) {
  1.2300 +        ckfree((char *) statePtr->curOutPtr);
  1.2301 +        statePtr->curOutPtr = (ChannelBuffer *) NULL;
  1.2302 +    }
  1.2303 +    
  1.2304 +    /*
  1.2305 +     * The caller guarantees that there are no more buffers
  1.2306 +     * queued for output.
  1.2307 +     */
  1.2308 +
  1.2309 +    if (statePtr->outQueueHead != (ChannelBuffer *) NULL) {
  1.2310 +        panic("TclFlush, closed channel: queued output left");
  1.2311 +    }
  1.2312 +
  1.2313 +    /*
  1.2314 +     * If the EOF character is set in the channel, append that to the
  1.2315 +     * output device.
  1.2316 +     */
  1.2317 +
  1.2318 +    if ((statePtr->outEofChar != 0) && (statePtr->flags & TCL_WRITABLE)) {
  1.2319 +        int dummy;
  1.2320 +        char c;
  1.2321 +
  1.2322 +        c = (char) statePtr->outEofChar;
  1.2323 +        (chanPtr->typePtr->outputProc) (chanPtr->instanceData, &c, 1, &dummy);
  1.2324 +    }
  1.2325 +
  1.2326 +    /*
  1.2327 +     * Remove this channel from of the list of all channels.
  1.2328 +     */
  1.2329 +    Tcl_CutChannel((Tcl_Channel) chanPtr);
  1.2330 +
  1.2331 +    /*
  1.2332 +     * Close and free the channel driver state.
  1.2333 +     */
  1.2334 +
  1.2335 +    if (chanPtr->typePtr->closeProc != TCL_CLOSE2PROC) {
  1.2336 +	result = (chanPtr->typePtr->closeProc)(chanPtr->instanceData, interp);
  1.2337 +    } else {
  1.2338 +	result = (chanPtr->typePtr->close2Proc)(chanPtr->instanceData, interp,
  1.2339 +		0);
  1.2340 +    }
  1.2341 +
  1.2342 +    /*
  1.2343 +     * Some resources can be cleared only if the bottom channel
  1.2344 +     * in a stack is closed. All the other channels in the stack
  1.2345 +     * are not allowed to remove.
  1.2346 +     */
  1.2347 +
  1.2348 +    if (chanPtr == statePtr->bottomChanPtr) {
  1.2349 +	if (statePtr->channelName != (char *) NULL) {
  1.2350 +	    ckfree((char *) statePtr->channelName);
  1.2351 +	    statePtr->channelName = NULL;
  1.2352 +	}
  1.2353 +
  1.2354 +	Tcl_FreeEncoding(statePtr->encoding);
  1.2355 +	if (statePtr->outputStage != NULL) {
  1.2356 +	    ckfree((char *) statePtr->outputStage);
  1.2357 +	    statePtr->outputStage = (char *) NULL;
  1.2358 +	}
  1.2359 +    }
  1.2360 +
  1.2361 +    /*
  1.2362 +     * If we are being called synchronously, report either
  1.2363 +     * any latent error on the channel or the current error.
  1.2364 +     */
  1.2365 +
  1.2366 +    if (statePtr->unreportedError != 0) {
  1.2367 +        errorCode = statePtr->unreportedError;
  1.2368 +    }
  1.2369 +    if (errorCode == 0) {
  1.2370 +        errorCode = result;
  1.2371 +        if (errorCode != 0) {
  1.2372 +            Tcl_SetErrno(errorCode);
  1.2373 +        }
  1.2374 +    }
  1.2375 +
  1.2376 +    /*
  1.2377 +     * Cancel any outstanding timer.
  1.2378 +     */
  1.2379 +
  1.2380 +    Tcl_DeleteTimerHandler(statePtr->timer);
  1.2381 +
  1.2382 +    /*
  1.2383 +     * Mark the channel as deleted by clearing the type structure.
  1.2384 +     */
  1.2385 +
  1.2386 +    if (chanPtr->downChanPtr != (Channel *) NULL) {
  1.2387 +	Channel *downChanPtr = chanPtr->downChanPtr;
  1.2388 +
  1.2389 +	statePtr->nextCSPtr	= tsdPtr->firstCSPtr;
  1.2390 +	tsdPtr->firstCSPtr	= statePtr;
  1.2391 +
  1.2392 +	statePtr->topChanPtr	= downChanPtr;
  1.2393 +	downChanPtr->upChanPtr	= (Channel *) NULL;
  1.2394 +	chanPtr->typePtr	= NULL;
  1.2395 +
  1.2396 +	Tcl_EventuallyFree((ClientData) chanPtr, TCL_DYNAMIC);
  1.2397 +	return Tcl_Close(interp, (Tcl_Channel) downChanPtr);
  1.2398 +    }
  1.2399 +
  1.2400 +    /*
  1.2401 +     * There is only the TOP Channel, so we free the remaining
  1.2402 +     * pointers we have and then ourselves.  Since this is the
  1.2403 +     * last of the channels in the stack, make sure to free the
  1.2404 +     * ChannelState structure associated with it.  We use
  1.2405 +     * Tcl_EventuallyFree to allow for any last
  1.2406 +     */
  1.2407 +    chanPtr->typePtr = NULL;
  1.2408 +
  1.2409 +    Tcl_EventuallyFree((ClientData) statePtr, TCL_DYNAMIC);
  1.2410 +    Tcl_EventuallyFree((ClientData) chanPtr, TCL_DYNAMIC);
  1.2411 +
  1.2412 +    return errorCode;
  1.2413 +}
  1.2414 +
  1.2415 +/*
  1.2416 + *----------------------------------------------------------------------
  1.2417 + *
  1.2418 + * Tcl_CutChannel --
  1.2419 + *
  1.2420 + *	Removes a channel from the (thread-)global list of all channels
  1.2421 + *	(in that thread).  This is actually the statePtr for the stack
  1.2422 + *	of channel.
  1.2423 + *
  1.2424 + * Results:
  1.2425 + *	Nothing.
  1.2426 + *
  1.2427 + * Side effects:
  1.2428 + *	Resets the field 'nextCSPtr' of the specified channel state to NULL.
  1.2429 + *
  1.2430 + * NOTE:
  1.2431 + *	The channel to cut out of the list must not be referenced
  1.2432 + *	in any interpreter. This is something this procedure cannot
  1.2433 + *	check (despite the refcount) because the caller usually wants
  1.2434 + *	fiddle with the channel (like transfering it to a different
  1.2435 + *	thread) and thus keeps the refcount artifically high to prevent
  1.2436 + *	its destruction.
  1.2437 + *
  1.2438 + *----------------------------------------------------------------------
  1.2439 + */
  1.2440 +
  1.2441 +EXPORT_C void
  1.2442 +Tcl_CutChannel(chan)
  1.2443 +    Tcl_Channel chan;			/* The channel being removed. Must
  1.2444 +                                         * not be referenced in any
  1.2445 +                                         * interpreter. */
  1.2446 +{
  1.2447 +    ThreadSpecificData* tsdPtr  = TCL_TSD_INIT(&dataKey);
  1.2448 +    ChannelState *prevCSPtr;		/* Preceding channel state in list of
  1.2449 +                                         * all states - used to splice a
  1.2450 +                                         * channel out of the list on close. */
  1.2451 +    ChannelState *statePtr = ((Channel *) chan)->state;
  1.2452 +					/* state of the channel stack. */
  1.2453 +    Tcl_DriverThreadActionProc *threadActionProc;
  1.2454 +
  1.2455 +    /*
  1.2456 +     * Remove this channel from of the list of all channels
  1.2457 +     * (in the current thread).
  1.2458 +     */
  1.2459 +
  1.2460 +    if (tsdPtr->firstCSPtr && (statePtr == tsdPtr->firstCSPtr)) {
  1.2461 +        tsdPtr->firstCSPtr = statePtr->nextCSPtr;
  1.2462 +    } else {
  1.2463 +        for (prevCSPtr = tsdPtr->firstCSPtr;
  1.2464 +	     prevCSPtr && (prevCSPtr->nextCSPtr != statePtr);
  1.2465 +	     prevCSPtr = prevCSPtr->nextCSPtr) {
  1.2466 +            /* Empty loop body. */
  1.2467 +        }
  1.2468 +        if (prevCSPtr == (ChannelState *) NULL) {
  1.2469 +            panic("FlushChannel: damaged channel list");
  1.2470 +        }
  1.2471 +        prevCSPtr->nextCSPtr = statePtr->nextCSPtr;
  1.2472 +    }
  1.2473 +
  1.2474 +    statePtr->nextCSPtr = (ChannelState *) NULL;
  1.2475 +
  1.2476 +    /* TIP #218, Channel Thread Actions */
  1.2477 +    threadActionProc = Tcl_ChannelThreadActionProc (Tcl_GetChannelType (chan));
  1.2478 +    if (threadActionProc != NULL) {
  1.2479 +        (*threadActionProc) (Tcl_GetChannelInstanceData(chan),
  1.2480 +			     TCL_CHANNEL_THREAD_REMOVE);
  1.2481 +    }
  1.2482 +}
  1.2483 +
  1.2484 +/*
  1.2485 + *----------------------------------------------------------------------
  1.2486 + *
  1.2487 + * Tcl_SpliceChannel --
  1.2488 + *
  1.2489 + *	Adds a channel to the (thread-)global list of all channels
  1.2490 + *	(in that thread). Expects that the field 'nextChanPtr' in
  1.2491 + *	the channel is set to NULL.
  1.2492 + *
  1.2493 + * Results:
  1.2494 + *	Nothing.
  1.2495 + *
  1.2496 + * Side effects:
  1.2497 + *	Nothing.
  1.2498 + *
  1.2499 + * NOTE:
  1.2500 + *	The channel to splice into the list must not be referenced in any
  1.2501 + *	interpreter. This is something this procedure cannot check
  1.2502 + *	(despite the refcount) because the caller usually wants figgle
  1.2503 + *	with the channel (like transfering it to a different thread)
  1.2504 + *	and thus keeps the refcount artifically high to prevent its
  1.2505 + *	destruction.
  1.2506 + *
  1.2507 + *----------------------------------------------------------------------
  1.2508 + */
  1.2509 +
  1.2510 +EXPORT_C void
  1.2511 +Tcl_SpliceChannel(chan)
  1.2512 +    Tcl_Channel chan;			/* The channel being added. Must
  1.2513 +                                         * not be referenced in any
  1.2514 +                                         * interpreter. */
  1.2515 +{
  1.2516 +    ThreadSpecificData	*tsdPtr = TCL_TSD_INIT(&dataKey);
  1.2517 +    ChannelState	*statePtr = ((Channel *) chan)->state;
  1.2518 +    Tcl_DriverThreadActionProc *threadActionProc;
  1.2519 +
  1.2520 +    if (statePtr->nextCSPtr != (ChannelState *) NULL) {
  1.2521 +        panic("Tcl_SpliceChannel: trying to add channel used in different list");
  1.2522 +    }
  1.2523 +
  1.2524 +    statePtr->nextCSPtr	= tsdPtr->firstCSPtr;
  1.2525 +    tsdPtr->firstCSPtr	= statePtr;
  1.2526 +
  1.2527 +    /*
  1.2528 +     * TIP #10. Mark the current thread as the new one managing this
  1.2529 +     *          channel. Note: 'Tcl_GetCurrentThread' returns sensible
  1.2530 +     *          values even for a non-threaded core.
  1.2531 +     */
  1.2532 +
  1.2533 +    statePtr->managingThread = Tcl_GetCurrentThread ();
  1.2534 +
  1.2535 +    /* TIP #218, Channel Thread Actions */
  1.2536 +    threadActionProc = Tcl_ChannelThreadActionProc (Tcl_GetChannelType (chan));
  1.2537 +    if (threadActionProc != NULL) {
  1.2538 +        (*threadActionProc) (Tcl_GetChannelInstanceData(chan),
  1.2539 +			     TCL_CHANNEL_THREAD_INSERT);
  1.2540 +    }
  1.2541 +}
  1.2542 +
  1.2543 +/*
  1.2544 + *----------------------------------------------------------------------
  1.2545 + *
  1.2546 + * Tcl_Close --
  1.2547 + *
  1.2548 + *	Closes a channel.
  1.2549 + *
  1.2550 + * Results:
  1.2551 + *	A standard Tcl result.
  1.2552 + *
  1.2553 + * Side effects:
  1.2554 + *	Closes the channel if this is the last reference.
  1.2555 + *
  1.2556 + * NOTE:
  1.2557 + *	Tcl_Close removes the channel as far as the user is concerned.
  1.2558 + *	However, it may continue to exist for a while longer if it has
  1.2559 + *	a background flush scheduled. The device itself is eventually
  1.2560 + *	closed and the channel record removed, in CloseChannel, above.
  1.2561 + *
  1.2562 + *----------------------------------------------------------------------
  1.2563 + */
  1.2564 +
  1.2565 +	/* ARGSUSED */
  1.2566 +EXPORT_C int
  1.2567 +Tcl_Close(interp, chan)
  1.2568 +    Tcl_Interp *interp;			/* Interpreter for errors. */
  1.2569 +    Tcl_Channel chan;			/* The channel being closed. Must
  1.2570 +                                         * not be referenced in any
  1.2571 +                                         * interpreter. */
  1.2572 +{
  1.2573 +    CloseCallback *cbPtr;		/* Iterate over close callbacks
  1.2574 +                                         * for this channel. */
  1.2575 +    Channel *chanPtr;			/* The real IO channel. */
  1.2576 +    ChannelState *statePtr;		/* State of real IO channel. */
  1.2577 +    int result;				/* Of calling FlushChannel. */
  1.2578 +
  1.2579 +    if (chan == (Tcl_Channel) NULL) {
  1.2580 +        return TCL_OK;
  1.2581 +    }
  1.2582 +
  1.2583 +    /*
  1.2584 +     * Perform special handling for standard channels being closed. If the
  1.2585 +     * refCount is now 1 it means that the last reference to the standard
  1.2586 +     * channel is being explicitly closed, so bump the refCount down
  1.2587 +     * artificially to 0. This will ensure that the channel is actually
  1.2588 +     * closed, below. Also set the static pointer to NULL for the channel.
  1.2589 +     */
  1.2590 +
  1.2591 +    CheckForStdChannelsBeingClosed(chan);
  1.2592 +
  1.2593 +    /*
  1.2594 +     * This operation should occur at the top of a channel stack.
  1.2595 +     */
  1.2596 +
  1.2597 +    chanPtr	= (Channel *) chan;
  1.2598 +    statePtr	= chanPtr->state;
  1.2599 +    chanPtr	= statePtr->topChanPtr;
  1.2600 +
  1.2601 +    if (statePtr->refCount > 0) {
  1.2602 +        panic("called Tcl_Close on channel with refCount > 0");
  1.2603 +    }
  1.2604 + 
  1.2605 +    if (statePtr->flags & CHANNEL_INCLOSE) {
  1.2606 +	if (interp) {
  1.2607 +            Tcl_AppendResult(interp,
  1.2608 +	    "Illegal recursive call to close through close-handler of channel",
  1.2609 +	    (char *) NULL);
  1.2610 +	}
  1.2611 +        return TCL_ERROR;
  1.2612 +    }
  1.2613 +    statePtr->flags |= CHANNEL_INCLOSE;
  1.2614 +
  1.2615 +    /*
  1.2616 +     * When the channel has an escape sequence driven encoding such as
  1.2617 +     * iso2022, the terminated escape sequence must write to the buffer.
  1.2618 +     */
  1.2619 +    if ((statePtr->encoding != NULL) && (statePtr->curOutPtr != NULL)
  1.2620 +	    && (CheckChannelErrors(statePtr, TCL_WRITABLE) == 0)) {
  1.2621 +        statePtr->outputEncodingFlags |= TCL_ENCODING_END;
  1.2622 +        WriteChars(chanPtr, "", 0);
  1.2623 +    }
  1.2624 +
  1.2625 +    Tcl_ClearChannelHandlers(chan);
  1.2626 +
  1.2627 +    /*
  1.2628 +     * Invoke the registered close callbacks and delete their records.
  1.2629 +     */
  1.2630 +
  1.2631 +    while (statePtr->closeCbPtr != (CloseCallback *) NULL) {
  1.2632 +        cbPtr = statePtr->closeCbPtr;
  1.2633 +        statePtr->closeCbPtr = cbPtr->nextPtr;
  1.2634 +        (cbPtr->proc) (cbPtr->clientData);
  1.2635 +        ckfree((char *) cbPtr);
  1.2636 +    }
  1.2637 +
  1.2638 +    statePtr->flags &= ~CHANNEL_INCLOSE;
  1.2639 +
  1.2640 +    /*
  1.2641 +     * Ensure that the last output buffer will be flushed.
  1.2642 +     */
  1.2643 +    
  1.2644 +    if ((statePtr->curOutPtr != (ChannelBuffer *) NULL) &&
  1.2645 +	    (statePtr->curOutPtr->nextAdded > statePtr->curOutPtr->nextRemoved)) {
  1.2646 +        statePtr->flags |= BUFFER_READY;
  1.2647 +    }
  1.2648 +
  1.2649 +    /*
  1.2650 +     * If this channel supports it, close the read side, since we don't need it
  1.2651 +     * anymore and this will help avoid deadlocks on some channel types.
  1.2652 +     */
  1.2653 +
  1.2654 +    if (chanPtr->typePtr->closeProc == TCL_CLOSE2PROC) {
  1.2655 +	result = (chanPtr->typePtr->close2Proc)(chanPtr->instanceData, interp,
  1.2656 +		TCL_CLOSE_READ);
  1.2657 +    } else {
  1.2658 +	result = 0;
  1.2659 +    }
  1.2660 +
  1.2661 +    /*
  1.2662 +     * The call to FlushChannel will flush any queued output and invoke
  1.2663 +     * the close function of the channel driver, or it will set up the
  1.2664 +     * channel to be flushed and closed asynchronously.
  1.2665 +     */
  1.2666 +
  1.2667 +    statePtr->flags |= CHANNEL_CLOSED;
  1.2668 +    if ((FlushChannel(interp, chanPtr, 0) != 0) || (result != 0)) {
  1.2669 +        return TCL_ERROR;
  1.2670 +    }
  1.2671 +    return TCL_OK;
  1.2672 +}
  1.2673 +
  1.2674 +/*
  1.2675 + *----------------------------------------------------------------------
  1.2676 + *
  1.2677 + * Tcl_ClearChannelHandlers --
  1.2678 + *
  1.2679 + *	Removes all channel handlers and event scripts from the channel,
  1.2680 + *	cancels all background copies involving the channel and any interest
  1.2681 + *	in events.
  1.2682 + *
  1.2683 + * Results:
  1.2684 + *	None.
  1.2685 + *
  1.2686 + * Side effects:
  1.2687 + *	See above. Deallocates memory.
  1.2688 + *
  1.2689 + *----------------------------------------------------------------------
  1.2690 + */
  1.2691 +
  1.2692 +EXPORT_C void
  1.2693 +Tcl_ClearChannelHandlers (channel)
  1.2694 +    Tcl_Channel channel;
  1.2695 +{
  1.2696 +    ChannelHandler *chPtr, *chNext;	/* Iterate over channel handlers. */
  1.2697 +    EventScriptRecord *ePtr, *eNextPtr;	/* Iterate over eventscript records. */
  1.2698 +    Channel *chanPtr;			/* The real IO channel. */
  1.2699 +    ChannelState *statePtr;		/* State of real IO channel. */
  1.2700 +    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
  1.2701 +    NextChannelHandler *nhPtr;
  1.2702 +
  1.2703 +    /*
  1.2704 +     * This operation should occur at the top of a channel stack.
  1.2705 +     */
  1.2706 +
  1.2707 +    chanPtr	= (Channel *) channel;
  1.2708 +    statePtr	= chanPtr->state;
  1.2709 +    chanPtr	= statePtr->topChanPtr;
  1.2710 +
  1.2711 +    /*
  1.2712 +     * Cancel any outstanding timer.
  1.2713 +     */
  1.2714 +
  1.2715 +    Tcl_DeleteTimerHandler(statePtr->timer);
  1.2716 +
  1.2717 +    /*
  1.2718 +     * Remove any references to channel handlers for this channel that
  1.2719 +     * may be about to be invoked.
  1.2720 +     */
  1.2721 +
  1.2722 +    for (nhPtr = tsdPtr->nestedHandlerPtr;
  1.2723 +	 nhPtr != (NextChannelHandler *) NULL;
  1.2724 +	 nhPtr = nhPtr->nestedHandlerPtr) {
  1.2725 +        if (nhPtr->nextHandlerPtr &&
  1.2726 +		(nhPtr->nextHandlerPtr->chanPtr == chanPtr)) {
  1.2727 +	    nhPtr->nextHandlerPtr = NULL;
  1.2728 +        }
  1.2729 +    }
  1.2730 +
  1.2731 +    /*
  1.2732 +     * Remove all the channel handler records attached to the channel
  1.2733 +     * itself.
  1.2734 +     */
  1.2735 +
  1.2736 +    for (chPtr = statePtr->chPtr;
  1.2737 +	 chPtr != (ChannelHandler *) NULL;
  1.2738 +	 chPtr = chNext) {
  1.2739 +        chNext = chPtr->nextPtr;
  1.2740 +        ckfree((char *) chPtr);
  1.2741 +    }
  1.2742 +    statePtr->chPtr = (ChannelHandler *) NULL;
  1.2743 +
  1.2744 +    /*
  1.2745 +     * Cancel any pending copy operation.
  1.2746 +     */
  1.2747 +
  1.2748 +    StopCopy(statePtr->csPtr);
  1.2749 +
  1.2750 +    /*
  1.2751 +     * Must set the interest mask now to 0, otherwise infinite loops
  1.2752 +     * will occur if Tcl_DoOneEvent is called before the channel is
  1.2753 +     * finally deleted in FlushChannel. This can happen if the channel
  1.2754 +     * has a background flush active.
  1.2755 +     */
  1.2756 +
  1.2757 +    statePtr->interestMask = 0;
  1.2758 +
  1.2759 +    /*
  1.2760 +     * Remove any EventScript records for this channel.
  1.2761 +     */
  1.2762 +
  1.2763 +    for (ePtr = statePtr->scriptRecordPtr;
  1.2764 +	 ePtr != (EventScriptRecord *) NULL;
  1.2765 +	 ePtr = eNextPtr) {
  1.2766 +        eNextPtr = ePtr->nextPtr;
  1.2767 +	Tcl_DecrRefCount(ePtr->scriptPtr);
  1.2768 +        ckfree((char *) ePtr);
  1.2769 +    }
  1.2770 +    statePtr->scriptRecordPtr = (EventScriptRecord *) NULL;
  1.2771 +}
  1.2772 +
  1.2773 +/*
  1.2774 + *----------------------------------------------------------------------
  1.2775 + *
  1.2776 + * Tcl_Write --
  1.2777 + *
  1.2778 + *	Puts a sequence of bytes into an output buffer, may queue the
  1.2779 + *	buffer for output if it gets full, and also remembers whether the
  1.2780 + *	current buffer is ready e.g. if it contains a newline and we are in
  1.2781 + *	line buffering mode. Compensates stacking, i.e. will redirect the
  1.2782 + *	data from the specified channel to the topmost channel in a stack.
  1.2783 + *
  1.2784 + *	No encoding conversions are applied to the bytes being read.
  1.2785 + *
  1.2786 + * Results:
  1.2787 + *	The number of bytes written or -1 in case of error. If -1,
  1.2788 + *	Tcl_GetErrno will return the error code.
  1.2789 + *
  1.2790 + * Side effects:
  1.2791 + *	May buffer up output and may cause output to be produced on the
  1.2792 + *	channel.
  1.2793 + *
  1.2794 + *----------------------------------------------------------------------
  1.2795 + */
  1.2796 +
  1.2797 +EXPORT_C int
  1.2798 +Tcl_Write(chan, src, srcLen)
  1.2799 +    Tcl_Channel chan;			/* The channel to buffer output for. */
  1.2800 +    CONST char *src;			/* Data to queue in output buffer. */
  1.2801 +    int srcLen;				/* Length of data in bytes, or < 0 for
  1.2802 +					 * strlen(). */
  1.2803 +{
  1.2804 +    /*
  1.2805 +     * Always use the topmost channel of the stack
  1.2806 +     */
  1.2807 +    Channel *chanPtr;
  1.2808 +    ChannelState *statePtr;	/* state info for channel */
  1.2809 +
  1.2810 +    statePtr = ((Channel *) chan)->state;
  1.2811 +    chanPtr  = statePtr->topChanPtr;
  1.2812 +
  1.2813 +    if (CheckChannelErrors(statePtr, TCL_WRITABLE) != 0) {
  1.2814 +	return -1;
  1.2815 +    }
  1.2816 +
  1.2817 +    if (srcLen < 0) {
  1.2818 +        srcLen = strlen(src);
  1.2819 +    }
  1.2820 +    return DoWrite(chanPtr, src, srcLen);
  1.2821 +}
  1.2822 +
  1.2823 +/*
  1.2824 + *----------------------------------------------------------------------
  1.2825 + *
  1.2826 + * Tcl_WriteRaw --
  1.2827 + *
  1.2828 + *	Puts a sequence of bytes into an output buffer, may queue the
  1.2829 + *	buffer for output if it gets full, and also remembers whether the
  1.2830 + *	current buffer is ready e.g. if it contains a newline and we are in
  1.2831 + *	line buffering mode. Writes directly to the driver of the channel,
  1.2832 + *	does not compensate for stacking.
  1.2833 + *
  1.2834 + *	No encoding conversions are applied to the bytes being read.
  1.2835 + *
  1.2836 + * Results:
  1.2837 + *	The number of bytes written or -1 in case of error. If -1,
  1.2838 + *	Tcl_GetErrno will return the error code.
  1.2839 + *
  1.2840 + * Side effects:
  1.2841 + *	May buffer up output and may cause output to be produced on the
  1.2842 + *	channel.
  1.2843 + *
  1.2844 + *----------------------------------------------------------------------
  1.2845 + */
  1.2846 +
  1.2847 +EXPORT_C int
  1.2848 +Tcl_WriteRaw(chan, src, srcLen)
  1.2849 +    Tcl_Channel chan;			/* The channel to buffer output for. */
  1.2850 +    CONST char *src;			/* Data to queue in output buffer. */
  1.2851 +    int srcLen;				/* Length of data in bytes, or < 0 for
  1.2852 +					 * strlen(). */
  1.2853 +{
  1.2854 +    Channel *chanPtr = ((Channel *) chan);
  1.2855 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.2856 +    int errorCode, written;
  1.2857 +
  1.2858 +    if (CheckChannelErrors(statePtr, TCL_WRITABLE | CHANNEL_RAW_MODE) != 0) {
  1.2859 +	return -1;
  1.2860 +    }
  1.2861 +
  1.2862 +    if (srcLen < 0) {
  1.2863 +        srcLen = strlen(src);
  1.2864 +    }
  1.2865 +
  1.2866 +    /*
  1.2867 +     * Go immediately to the driver, do all the error handling by ourselves.
  1.2868 +     * The code was stolen from 'FlushChannel'.
  1.2869 +     */
  1.2870 +
  1.2871 +    written = (chanPtr->typePtr->outputProc) (chanPtr->instanceData,
  1.2872 +	    src, srcLen, &errorCode);
  1.2873 +
  1.2874 +    if (written < 0) {
  1.2875 +	Tcl_SetErrno(errorCode);
  1.2876 +    }
  1.2877 +
  1.2878 +    return written;
  1.2879 +}
  1.2880 +
  1.2881 +/*
  1.2882 + *---------------------------------------------------------------------------
  1.2883 + *
  1.2884 + * Tcl_WriteChars --
  1.2885 + *
  1.2886 + *	Takes a sequence of UTF-8 characters and converts them for output
  1.2887 + *	using the channel's current encoding, may queue the buffer for
  1.2888 + *	output if it gets full, and also remembers whether the current
  1.2889 + *	buffer is ready e.g. if it contains a newline and we are in
  1.2890 + *	line buffering mode. Compensates stacking, i.e. will redirect the
  1.2891 + *	data from the specified channel to the topmost channel in a stack.
  1.2892 + *
  1.2893 + * Results:
  1.2894 + *	The number of bytes written or -1 in case of error. If -1,
  1.2895 + *	Tcl_GetErrno will return the error code.
  1.2896 + *
  1.2897 + * Side effects:
  1.2898 + *	May buffer up output and may cause output to be produced on the
  1.2899 + *	channel.
  1.2900 + *
  1.2901 + *----------------------------------------------------------------------
  1.2902 + */
  1.2903 +
  1.2904 +EXPORT_C int
  1.2905 +Tcl_WriteChars(chan, src, len)
  1.2906 +    Tcl_Channel chan;		/* The channel to buffer output for. */
  1.2907 +    CONST char *src;		/* UTF-8 characters to queue in output buffer. */
  1.2908 +    int len;			/* Length of string in bytes, or < 0 for 
  1.2909 +				 * strlen(). */
  1.2910 +{
  1.2911 +    ChannelState *statePtr;	/* state info for channel */
  1.2912 +
  1.2913 +    statePtr = ((Channel *) chan)->state;
  1.2914 +
  1.2915 +    if (CheckChannelErrors(statePtr, TCL_WRITABLE) != 0) {
  1.2916 +	return -1;
  1.2917 +    }
  1.2918 +
  1.2919 +    return DoWriteChars ((Channel*) chan, src, len);
  1.2920 +}
  1.2921 +
  1.2922 +/*
  1.2923 + *---------------------------------------------------------------------------
  1.2924 + *
  1.2925 + * DoWriteChars --
  1.2926 + *
  1.2927 + *	Takes a sequence of UTF-8 characters and converts them for output
  1.2928 + *	using the channel's current encoding, may queue the buffer for
  1.2929 + *	output if it gets full, and also remembers whether the current
  1.2930 + *	buffer is ready e.g. if it contains a newline and we are in
  1.2931 + *	line buffering mode. Compensates stacking, i.e. will redirect the
  1.2932 + *	data from the specified channel to the topmost channel in a stack.
  1.2933 + *
  1.2934 + * Results:
  1.2935 + *	The number of bytes written or -1 in case of error. If -1,
  1.2936 + *	Tcl_GetErrno will return the error code.
  1.2937 + *
  1.2938 + * Side effects:
  1.2939 + *	May buffer up output and may cause output to be produced on the
  1.2940 + *	channel.
  1.2941 + *
  1.2942 + *----------------------------------------------------------------------
  1.2943 + */
  1.2944 +
  1.2945 +static int
  1.2946 +DoWriteChars(chanPtr, src, len)
  1.2947 +    Channel* chanPtr;		/* The channel to buffer output for. */
  1.2948 +    CONST char *src;		/* UTF-8 characters to queue in output buffer. */
  1.2949 +    int len;			/* Length of string in bytes, or < 0 for 
  1.2950 +				 * strlen(). */
  1.2951 +{
  1.2952 +    /*
  1.2953 +     * Always use the topmost channel of the stack
  1.2954 +     */
  1.2955 +    ChannelState *statePtr;	/* state info for channel */
  1.2956 +
  1.2957 +    statePtr = chanPtr->state;
  1.2958 +    chanPtr  = statePtr->topChanPtr;
  1.2959 +
  1.2960 +    if (len < 0) {
  1.2961 +        len = strlen(src);
  1.2962 +    }
  1.2963 +    if (statePtr->encoding == NULL) {
  1.2964 +	/*
  1.2965 +	 * Inefficient way to convert UTF-8 to byte-array, but the  
  1.2966 +	 * code parallels the way it is done for objects.
  1.2967 +	 */
  1.2968 +
  1.2969 +	Tcl_Obj *objPtr;
  1.2970 +	int result;
  1.2971 +
  1.2972 +	objPtr = Tcl_NewStringObj(src, len);
  1.2973 +	src = (char *) Tcl_GetByteArrayFromObj(objPtr, &len);
  1.2974 +	result = WriteBytes(chanPtr, src, len);
  1.2975 +	Tcl_DecrRefCount(objPtr);
  1.2976 +	return result;
  1.2977 +    }
  1.2978 +    return WriteChars(chanPtr, src, len);
  1.2979 +}
  1.2980 +
  1.2981 +/*
  1.2982 + *---------------------------------------------------------------------------
  1.2983 + *
  1.2984 + * Tcl_WriteObj --
  1.2985 + *
  1.2986 + *	Takes the Tcl object and queues its contents for output.  If the 
  1.2987 + *	encoding of the channel is NULL, takes the byte-array representation 
  1.2988 + *	of the object and queues those bytes for output.  Otherwise, takes 
  1.2989 + *	the characters in the UTF-8 (string) representation of the object 
  1.2990 + *	and converts them for output using the channel's current encoding.  
  1.2991 + *	May flush internal buffers to output if one becomes full or is ready 
  1.2992 + *	for some other reason, e.g. if it contains a newline and the channel 
  1.2993 + *	is in line buffering mode.
  1.2994 + *
  1.2995 + * Results:
  1.2996 + *	The number of bytes written or -1 in case of error. If -1, 
  1.2997 + *	Tcl_GetErrno() will return the error code.
  1.2998 + *
  1.2999 + * Side effects:
  1.3000 + *	May buffer up output and may cause output to be produced on the
  1.3001 + *	channel.
  1.3002 + *
  1.3003 + *----------------------------------------------------------------------
  1.3004 + */
  1.3005 +
  1.3006 +EXPORT_C int
  1.3007 +Tcl_WriteObj(chan, objPtr)
  1.3008 +    Tcl_Channel chan;		/* The channel to buffer output for. */
  1.3009 +    Tcl_Obj *objPtr;		/* The object to write. */
  1.3010 +{
  1.3011 +    /*
  1.3012 +     * Always use the topmost channel of the stack
  1.3013 +     */
  1.3014 +    Channel *chanPtr;
  1.3015 +    ChannelState *statePtr;	/* state info for channel */
  1.3016 +    char *src;
  1.3017 +    int srcLen;
  1.3018 +
  1.3019 +    statePtr = ((Channel *) chan)->state;
  1.3020 +    chanPtr  = statePtr->topChanPtr;
  1.3021 +
  1.3022 +    if (CheckChannelErrors(statePtr, TCL_WRITABLE) != 0) {
  1.3023 +	return -1;
  1.3024 +    }
  1.3025 +    if (statePtr->encoding == NULL) {
  1.3026 +	src = (char *) Tcl_GetByteArrayFromObj(objPtr, &srcLen);
  1.3027 +	return WriteBytes(chanPtr, src, srcLen);
  1.3028 +    } else {
  1.3029 +	src = Tcl_GetStringFromObj(objPtr, &srcLen);
  1.3030 +	return WriteChars(chanPtr, src, srcLen);
  1.3031 +    }
  1.3032 +}
  1.3033 +
  1.3034 +/*
  1.3035 + *----------------------------------------------------------------------
  1.3036 + *
  1.3037 + * WriteBytes --
  1.3038 + *
  1.3039 + *	Write a sequence of bytes into an output buffer, may queue the
  1.3040 + *	buffer for output if it gets full, and also remembers whether the
  1.3041 + *	current buffer is ready e.g. if it contains a newline and we are in
  1.3042 + *	line buffering mode.
  1.3043 + *
  1.3044 + * Results:
  1.3045 + *	The number of bytes written or -1 in case of error. If -1,
  1.3046 + *	Tcl_GetErrno will return the error code.
  1.3047 + *
  1.3048 + * Side effects:
  1.3049 + *	May buffer up output and may cause output to be produced on the
  1.3050 + *	channel.
  1.3051 + *
  1.3052 + *----------------------------------------------------------------------
  1.3053 + */
  1.3054 +
  1.3055 +static int
  1.3056 +WriteBytes(chanPtr, src, srcLen)
  1.3057 +    Channel *chanPtr;		/* The channel to buffer output for. */
  1.3058 +    CONST char *src;		/* Bytes to write. */
  1.3059 +    int srcLen;			/* Number of bytes to write. */
  1.3060 +{
  1.3061 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.3062 +    ChannelBuffer *bufPtr;
  1.3063 +    char *dst;
  1.3064 +    int dstMax, sawLF, savedLF, total, dstLen, toWrite;
  1.3065 +    
  1.3066 +    total = 0;
  1.3067 +    sawLF = 0;
  1.3068 +    savedLF = 0;
  1.3069 +
  1.3070 +    /*
  1.3071 +     * Loop over all bytes in src, storing them in output buffer with
  1.3072 +     * proper EOL translation.
  1.3073 +     */
  1.3074 +
  1.3075 +    while (srcLen + savedLF > 0) {
  1.3076 +	bufPtr = statePtr->curOutPtr;
  1.3077 +	if (bufPtr == NULL) {
  1.3078 +	    bufPtr = AllocChannelBuffer(statePtr->bufSize);
  1.3079 +	    statePtr->curOutPtr	= bufPtr;
  1.3080 +	}
  1.3081 +	dst = bufPtr->buf + bufPtr->nextAdded;
  1.3082 +	dstMax = bufPtr->bufLength - bufPtr->nextAdded;
  1.3083 +	dstLen = dstMax;
  1.3084 +
  1.3085 +	toWrite = dstLen;
  1.3086 +	if (toWrite > srcLen) {
  1.3087 +	    toWrite = srcLen;
  1.3088 +	}
  1.3089 +
  1.3090 +	if (savedLF) {
  1.3091 +	    /*
  1.3092 +	     * A '\n' was left over from last call to TranslateOutputEOL()
  1.3093 +	     * and we need to store it in this buffer.  If the channel is
  1.3094 +	     * line-based, we will need to flush it.
  1.3095 +	     */
  1.3096 +
  1.3097 +	    *dst++ = '\n';
  1.3098 +	    dstLen--;
  1.3099 +	    sawLF++;
  1.3100 +	}
  1.3101 +	sawLF += TranslateOutputEOL(statePtr, dst, src, &dstLen, &toWrite);
  1.3102 +	dstLen += savedLF;
  1.3103 +	savedLF = 0;
  1.3104 +
  1.3105 +	if (dstLen > dstMax) {
  1.3106 +	    savedLF = 1;
  1.3107 +	    dstLen = dstMax;
  1.3108 +	}
  1.3109 +	bufPtr->nextAdded += dstLen;
  1.3110 +	if (CheckFlush(chanPtr, bufPtr, sawLF) != 0) {
  1.3111 +	    return -1;
  1.3112 +	}
  1.3113 +	total += dstLen;
  1.3114 +	src += toWrite;
  1.3115 +	srcLen -= toWrite;
  1.3116 +	sawLF = 0;
  1.3117 +    }
  1.3118 +    return total;
  1.3119 +}
  1.3120 +
  1.3121 +/*
  1.3122 + *----------------------------------------------------------------------
  1.3123 + *
  1.3124 + * WriteChars --
  1.3125 + *
  1.3126 + *	Convert UTF-8 bytes to the channel's external encoding and
  1.3127 + *	write the produced bytes into an output buffer, may queue the 
  1.3128 + *	buffer for output if it gets full, and also remembers whether the
  1.3129 + *	current buffer is ready e.g. if it contains a newline and we are in
  1.3130 + *	line buffering mode.
  1.3131 + *
  1.3132 + * Results:
  1.3133 + *	The number of bytes written or -1 in case of error. If -1,
  1.3134 + *	Tcl_GetErrno will return the error code.
  1.3135 + *
  1.3136 + * Side effects:
  1.3137 + *	May buffer up output and may cause output to be produced on the
  1.3138 + *	channel.
  1.3139 + *
  1.3140 + *----------------------------------------------------------------------
  1.3141 + */
  1.3142 +
  1.3143 +static int
  1.3144 +WriteChars(chanPtr, src, srcLen)
  1.3145 +    Channel *chanPtr;		/* The channel to buffer output for. */
  1.3146 +    CONST char *src;		/* UTF-8 string to write. */
  1.3147 +    int srcLen;			/* Length of UTF-8 string in bytes. */
  1.3148 +{
  1.3149 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.3150 +    ChannelBuffer *bufPtr;
  1.3151 +    char *dst, *stage;
  1.3152 +    int saved, savedLF, sawLF, total, dstLen, stageMax, dstWrote;
  1.3153 +    int stageLen, toWrite, stageRead, endEncoding, result;
  1.3154 +    int consumedSomething;
  1.3155 +    Tcl_Encoding encoding;
  1.3156 +    char safe[BUFFER_PADDING];
  1.3157 +    
  1.3158 +    total = 0;
  1.3159 +    sawLF = 0;
  1.3160 +    savedLF = 0;
  1.3161 +    saved = 0;
  1.3162 +    encoding = statePtr->encoding;
  1.3163 +
  1.3164 +    /*
  1.3165 +     * Write the terminated escape sequence even if srcLen is 0.
  1.3166 +     */
  1.3167 +
  1.3168 +    endEncoding = ((statePtr->outputEncodingFlags & TCL_ENCODING_END) != 0);
  1.3169 +
  1.3170 +    /*
  1.3171 +     * Loop over all UTF-8 characters in src, storing them in staging buffer
  1.3172 +     * with proper EOL translation.
  1.3173 +     */
  1.3174 +
  1.3175 +    consumedSomething = 1;
  1.3176 +    while (consumedSomething && (srcLen + savedLF + endEncoding > 0)) {
  1.3177 +        consumedSomething = 0;
  1.3178 +	stage = statePtr->outputStage;
  1.3179 +	stageMax = statePtr->bufSize;
  1.3180 +	stageLen = stageMax;
  1.3181 +
  1.3182 +	toWrite = stageLen;
  1.3183 +	if (toWrite > srcLen) {
  1.3184 +	    toWrite = srcLen;
  1.3185 +	}
  1.3186 +
  1.3187 +	if (savedLF) {
  1.3188 +	    /*
  1.3189 +	     * A '\n' was left over from last call to TranslateOutputEOL()
  1.3190 +	     * and we need to store it in the staging buffer.  If the
  1.3191 +	     * channel is line-based, we will need to flush the output
  1.3192 +	     * buffer (after translating the staging buffer).
  1.3193 +	     */
  1.3194 +	    
  1.3195 +	    *stage++ = '\n';
  1.3196 +	    stageLen--;
  1.3197 +	    sawLF++;
  1.3198 +	}
  1.3199 +	sawLF += TranslateOutputEOL(statePtr, stage, src, &stageLen, &toWrite);
  1.3200 +
  1.3201 +	stage -= savedLF;
  1.3202 +	stageLen += savedLF;
  1.3203 +	savedLF = 0;
  1.3204 +
  1.3205 +	if (stageLen > stageMax) {
  1.3206 +	    savedLF = 1;
  1.3207 +	    stageLen = stageMax;
  1.3208 +	}
  1.3209 +	src += toWrite;
  1.3210 +	srcLen -= toWrite;
  1.3211 +
  1.3212 +	/*
  1.3213 +	 * Loop over all UTF-8 characters in staging buffer, converting them
  1.3214 +	 * to external encoding, storing them in output buffer.
  1.3215 +	 */
  1.3216 +
  1.3217 +	while (stageLen + saved + endEncoding > 0) {
  1.3218 +	    bufPtr = statePtr->curOutPtr;
  1.3219 +	    if (bufPtr == NULL) {
  1.3220 +		bufPtr = AllocChannelBuffer(statePtr->bufSize);
  1.3221 +		statePtr->curOutPtr = bufPtr;
  1.3222 +	    }
  1.3223 +	    dst = bufPtr->buf + bufPtr->nextAdded;
  1.3224 +	    dstLen = bufPtr->bufLength - bufPtr->nextAdded;
  1.3225 +
  1.3226 +	    if (saved != 0) {
  1.3227 +		/*
  1.3228 +		 * Here's some translated bytes left over from the last
  1.3229 +		 * buffer that we need to stick at the beginning of this
  1.3230 +		 * buffer.
  1.3231 +		 */
  1.3232 +		 
  1.3233 +		memcpy((VOID *) dst, (VOID *) safe, (size_t) saved);
  1.3234 +		bufPtr->nextAdded += saved;
  1.3235 +		dst += saved;
  1.3236 +		dstLen -= saved;
  1.3237 +		saved = 0;
  1.3238 +	    }
  1.3239 +
  1.3240 +	    result = Tcl_UtfToExternal(NULL, encoding, stage, stageLen,
  1.3241 +		    statePtr->outputEncodingFlags,
  1.3242 +		    &statePtr->outputEncodingState, dst,
  1.3243 +		    dstLen + BUFFER_PADDING, &stageRead, &dstWrote, NULL);
  1.3244 +
  1.3245 +	    /* Fix for SF #506297, reported by Martin Forssen
  1.3246 +	     * <ruric@users.sourceforge.net>.
  1.3247 +	     *
  1.3248 +	     * The encoding chosen in the script exposing the bug writes out
  1.3249 +	     * three intro characters when TCL_ENCODING_START is set, but does
  1.3250 +	     * not consume any input as TCL_ENCODING_END is cleared. As some
  1.3251 +	     * output was generated the enclosing loop calls UtfToExternal
  1.3252 +	     * again, again with START set. Three more characters in the out
  1.3253 +	     * and still no use of input ... To break this infinite loop we
  1.3254 +	     * remove TCL_ENCODING_START from the set of flags after the first
  1.3255 +	     * call (no condition is required, the later calls remove an unset
  1.3256 +	     * flag, which is a no-op). This causes the subsequent calls to
  1.3257 +	     * UtfToExternal to consume and convert the actual input.
  1.3258 +	     */
  1.3259 +
  1.3260 +	    statePtr->outputEncodingFlags &= ~TCL_ENCODING_START;
  1.3261 +	    /*
  1.3262 +	     * The following code must be executed only when result is not 0.
  1.3263 +	     */
  1.3264 +	    if (result && ((stageRead + dstWrote) == 0)) {
  1.3265 +		/*
  1.3266 +		 * We have an incomplete UTF-8 character at the end of the
  1.3267 +		 * staging buffer.  It will get moved to the beginning of the
  1.3268 +		 * staging buffer followed by more bytes from src.
  1.3269 +		 */
  1.3270 +
  1.3271 +		src -= stageLen;
  1.3272 +		srcLen += stageLen;
  1.3273 +		stageLen = 0;
  1.3274 +		savedLF = 0;
  1.3275 +		break;
  1.3276 +	    }
  1.3277 +	    bufPtr->nextAdded += dstWrote;
  1.3278 +	    if (bufPtr->nextAdded > bufPtr->bufLength) {
  1.3279 +		/*
  1.3280 +		 * When translating from UTF-8 to external encoding, we
  1.3281 +		 * allowed the translation to produce a character that
  1.3282 +		 * crossed the end of the output buffer, so that we would
  1.3283 +		 * get a completely full buffer before flushing it.  The
  1.3284 +		 * extra bytes will be moved to the beginning of the next
  1.3285 +		 * buffer.
  1.3286 +		 */
  1.3287 +
  1.3288 +		saved = bufPtr->nextAdded - bufPtr->bufLength;
  1.3289 +		memcpy((VOID *) safe, (VOID *) (dst + dstLen), (size_t) saved);
  1.3290 +		bufPtr->nextAdded = bufPtr->bufLength;
  1.3291 +	    }
  1.3292 +	    if (CheckFlush(chanPtr, bufPtr, sawLF) != 0) {
  1.3293 +		return -1;
  1.3294 +	    }
  1.3295 +
  1.3296 +	    total += dstWrote;
  1.3297 +	    stage += stageRead;
  1.3298 +	    stageLen -= stageRead;
  1.3299 +	    sawLF = 0;
  1.3300 +
  1.3301 +	    consumedSomething = 1;
  1.3302 +
  1.3303 +	    /*
  1.3304 +	     * If all translated characters are written to the buffer,
  1.3305 +	     * endEncoding is set to 0 because the escape sequence may be
  1.3306 +	     * output.
  1.3307 +	     */
  1.3308 +
  1.3309 +	    if ((stageLen + saved == 0) && (result == 0)) {
  1.3310 +		endEncoding = 0;
  1.3311 +	    }
  1.3312 +	}
  1.3313 +    }
  1.3314 +
  1.3315 +    /* If nothing was written and it happened because there was no progress
  1.3316 +     * in the UTF conversion, we throw an error.
  1.3317 +     */
  1.3318 +
  1.3319 +    if (!consumedSomething && (total == 0)) {
  1.3320 +        Tcl_SetErrno (EINVAL);
  1.3321 +        return -1;
  1.3322 +    }
  1.3323 +    return total;
  1.3324 +}
  1.3325 +
  1.3326 +/*
  1.3327 + *---------------------------------------------------------------------------
  1.3328 + *
  1.3329 + * TranslateOutputEOL --
  1.3330 + *
  1.3331 + *	Helper function for WriteBytes() and WriteChars().  Converts the
  1.3332 + *	'\n' characters in the source buffer into the appropriate EOL
  1.3333 + *	form specified by the output translation mode.
  1.3334 + *
  1.3335 + *	EOL translation stops either when the source buffer is empty
  1.3336 + *	or the output buffer is full.
  1.3337 + *
  1.3338 + *	When converting to CRLF mode and there is only 1 byte left in
  1.3339 + *	the output buffer, this routine stores the '\r' in the last
  1.3340 + *	byte and then stores the '\n' in the byte just past the end of the 
  1.3341 + *	buffer.  The caller is responsible for passing in a buffer that
  1.3342 + *	is large enough to hold the extra byte.
  1.3343 + *
  1.3344 + * Results:
  1.3345 + *	The return value is 1 if a '\n' was translated from the source
  1.3346 + *	buffer, or 0 otherwise -- this can be used by the caller to
  1.3347 + *	decide to flush a line-based channel even though the channel
  1.3348 + *	buffer is not full.
  1.3349 + *
  1.3350 + *	*dstLenPtr is filled with how many bytes of the output buffer
  1.3351 + *	were used.  As mentioned above, this can be one more that
  1.3352 + *	the output buffer's specified length if a CRLF was stored.
  1.3353 + *
  1.3354 + *	*srcLenPtr is filled with how many bytes of the source buffer
  1.3355 + *	were consumed.  
  1.3356 + *
  1.3357 + * Side effects:
  1.3358 + *	It may be obvious, but bears mentioning that when converting
  1.3359 + *	in CRLF mode (which requires two bytes of storage in the output
  1.3360 + *	buffer), the number of bytes consumed from the source buffer
  1.3361 + *	will be less than the number of bytes stored in the output buffer.
  1.3362 + *
  1.3363 + *---------------------------------------------------------------------------
  1.3364 + */
  1.3365 +
  1.3366 +static int
  1.3367 +TranslateOutputEOL(statePtr, dst, src, dstLenPtr, srcLenPtr)
  1.3368 +    ChannelState *statePtr;	/* Channel being read, for translation and
  1.3369 +				 * buffering modes. */
  1.3370 +    char *dst;			/* Output buffer filled with UTF-8 chars by
  1.3371 +				 * applying appropriate EOL translation to
  1.3372 +				 * source characters. */
  1.3373 +    CONST char *src;		/* Source UTF-8 characters. */
  1.3374 +    int *dstLenPtr;		/* On entry, the maximum length of output
  1.3375 +				 * buffer in bytes.  On exit, the number of
  1.3376 +				 * bytes actually used in output buffer. */
  1.3377 +    int *srcLenPtr;		/* On entry, the length of source buffer.
  1.3378 +				 * On exit, the number of bytes read from
  1.3379 +				 * the source buffer. */
  1.3380 +{
  1.3381 +    char *dstEnd;
  1.3382 +    int srcLen, newlineFound;
  1.3383 +    
  1.3384 +    newlineFound = 0;
  1.3385 +    srcLen = *srcLenPtr;
  1.3386 +
  1.3387 +    switch (statePtr->outputTranslation) {
  1.3388 +	case TCL_TRANSLATE_LF: {
  1.3389 +	    for (dstEnd = dst + srcLen; dst < dstEnd; ) {
  1.3390 +		if (*src == '\n') {
  1.3391 +		    newlineFound = 1;
  1.3392 +		}
  1.3393 +		*dst++ = *src++;
  1.3394 +	    }
  1.3395 +	    *dstLenPtr = srcLen;
  1.3396 +	    break;
  1.3397 +	}
  1.3398 +	case TCL_TRANSLATE_CR: {
  1.3399 +	    for (dstEnd = dst + srcLen; dst < dstEnd;) {
  1.3400 +		if (*src == '\n') {
  1.3401 +		    *dst++ = '\r';
  1.3402 +		    newlineFound = 1;
  1.3403 +		    src++;
  1.3404 +		} else {
  1.3405 +		    *dst++ = *src++;
  1.3406 +		}
  1.3407 +	    }
  1.3408 +	    *dstLenPtr = srcLen;
  1.3409 +	    break;
  1.3410 +	}
  1.3411 +	case TCL_TRANSLATE_CRLF: {
  1.3412 +	    /*
  1.3413 +	     * Since this causes the number of bytes to grow, we
  1.3414 +	     * start off trying to put 'srcLen' bytes into the
  1.3415 +	     * output buffer, but allow it to store more bytes, as
  1.3416 +	     * long as there's still source bytes and room in the
  1.3417 +	     * output buffer.
  1.3418 +	     */
  1.3419 +
  1.3420 +	    char *dstStart, *dstMax;
  1.3421 +	    CONST char *srcStart;
  1.3422 +	    
  1.3423 +	    dstStart = dst;
  1.3424 +	    dstMax = dst + *dstLenPtr;
  1.3425 +
  1.3426 +	    srcStart = src;
  1.3427 +	    
  1.3428 +	    if (srcLen < *dstLenPtr) {
  1.3429 +		dstEnd = dst + srcLen;
  1.3430 +	    } else {
  1.3431 +		dstEnd = dst + *dstLenPtr;
  1.3432 +	    }
  1.3433 +	    while (dst < dstEnd) {
  1.3434 +		if (*src == '\n') {
  1.3435 +		    if (dstEnd < dstMax) {
  1.3436 +			dstEnd++;
  1.3437 +		    }
  1.3438 +		    *dst++ = '\r';
  1.3439 +		    newlineFound = 1;
  1.3440 +		}
  1.3441 +		*dst++ = *src++;
  1.3442 +	    }
  1.3443 +	    *srcLenPtr = src - srcStart;
  1.3444 +	    *dstLenPtr = dst - dstStart;
  1.3445 +	    break;
  1.3446 +	}
  1.3447 +	default: {
  1.3448 +	    break;
  1.3449 +	}
  1.3450 +    }
  1.3451 +    return newlineFound;
  1.3452 +}
  1.3453 +
  1.3454 +/*
  1.3455 + *---------------------------------------------------------------------------
  1.3456 + *
  1.3457 + * CheckFlush --
  1.3458 + *
  1.3459 + *	Helper function for WriteBytes() and WriteChars().  If the
  1.3460 + *	channel buffer is ready to be flushed, flush it.
  1.3461 + *
  1.3462 + * Results:
  1.3463 + *	The return value is -1 if there was a problem flushing the
  1.3464 + *	channel buffer, or 0 otherwise.
  1.3465 + *
  1.3466 + * Side effects:
  1.3467 + *	The buffer will be recycled if it is flushed.
  1.3468 + *
  1.3469 + *---------------------------------------------------------------------------
  1.3470 + */
  1.3471 +
  1.3472 +static int
  1.3473 +CheckFlush(chanPtr, bufPtr, newlineFlag)
  1.3474 +    Channel *chanPtr;		/* Channel being read, for buffering mode. */
  1.3475 +    ChannelBuffer *bufPtr;	/* Channel buffer to possibly flush. */
  1.3476 +    int newlineFlag;		/* Non-zero if a the channel buffer
  1.3477 +				 * contains a newline. */
  1.3478 +{
  1.3479 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.3480 +    /*
  1.3481 +     * The current buffer is ready for output:
  1.3482 +     * 1. if it is full.
  1.3483 +     * 2. if it contains a newline and this channel is line-buffered.
  1.3484 +     * 3. if it contains any output and this channel is unbuffered.
  1.3485 +     */
  1.3486 +
  1.3487 +    if ((statePtr->flags & BUFFER_READY) == 0) {
  1.3488 +	if (bufPtr->nextAdded == bufPtr->bufLength) {
  1.3489 +	    statePtr->flags |= BUFFER_READY;
  1.3490 +	} else if (statePtr->flags & CHANNEL_LINEBUFFERED) {
  1.3491 +	    if (newlineFlag != 0) {
  1.3492 +		statePtr->flags |= BUFFER_READY;
  1.3493 +	    }
  1.3494 +	} else if (statePtr->flags & CHANNEL_UNBUFFERED) {
  1.3495 +	    statePtr->flags |= BUFFER_READY;
  1.3496 +	}
  1.3497 +    }
  1.3498 +    if (statePtr->flags & BUFFER_READY) {
  1.3499 +	if (FlushChannel(NULL, chanPtr, 0) != 0) {
  1.3500 +	    return -1;
  1.3501 +	}
  1.3502 +    }
  1.3503 +    return 0;
  1.3504 +}
  1.3505 +
  1.3506 +/*
  1.3507 + *---------------------------------------------------------------------------
  1.3508 + *
  1.3509 + * Tcl_Gets --
  1.3510 + *
  1.3511 + *	Reads a complete line of input from the channel into a Tcl_DString.
  1.3512 + *
  1.3513 + * Results:
  1.3514 + *	Length of line read (in characters) or -1 if error, EOF, or blocked.
  1.3515 + *	If -1, use Tcl_GetErrno() to retrieve the POSIX error code for the
  1.3516 + *	error or condition that occurred.
  1.3517 + *
  1.3518 + * Side effects:
  1.3519 + *	May flush output on the channel.  May cause input to be consumed
  1.3520 + *	from the channel.
  1.3521 + *
  1.3522 + *---------------------------------------------------------------------------
  1.3523 + */
  1.3524 +
  1.3525 +EXPORT_C int
  1.3526 +Tcl_Gets(chan, lineRead)
  1.3527 +    Tcl_Channel chan;		/* Channel from which to read. */
  1.3528 +    Tcl_DString *lineRead;	/* The line read will be appended to this
  1.3529 +				 * DString as UTF-8 characters.  The caller
  1.3530 +				 * must have initialized it and is responsible
  1.3531 +				 * for managing the storage. */
  1.3532 +{
  1.3533 +    Tcl_Obj *objPtr;
  1.3534 +    int charsStored, length;
  1.3535 +    char *string;
  1.3536 +
  1.3537 +    objPtr = Tcl_NewObj();
  1.3538 +    charsStored = Tcl_GetsObj(chan, objPtr);
  1.3539 +    if (charsStored > 0) {
  1.3540 +	string = Tcl_GetStringFromObj(objPtr, &length);
  1.3541 +	Tcl_DStringAppend(lineRead, string, length);
  1.3542 +    }
  1.3543 +    Tcl_DecrRefCount(objPtr);
  1.3544 +    return charsStored;
  1.3545 +}
  1.3546 +
  1.3547 +/*
  1.3548 + *---------------------------------------------------------------------------
  1.3549 + *
  1.3550 + * Tcl_GetsObj --
  1.3551 + *
  1.3552 + *	Accumulate input from the input channel until end-of-line or
  1.3553 + *	end-of-file has been seen.  Bytes read from the input channel
  1.3554 + *	are converted to UTF-8 using the encoding specified by the
  1.3555 + *	channel.
  1.3556 + *
  1.3557 + * Results:
  1.3558 + *	Number of characters accumulated in the object or -1 if error,
  1.3559 + *	blocked, or EOF.  If -1, use Tcl_GetErrno() to retrieve the
  1.3560 + *	POSIX error code for the error or condition that occurred.
  1.3561 + *
  1.3562 + * Side effects:
  1.3563 + *	Consumes input from the channel.
  1.3564 + *
  1.3565 + *	On reading EOF, leave channel pointing at EOF char.
  1.3566 + *	On reading EOL, leave channel pointing after EOL, but don't
  1.3567 + *	return EOL in dst buffer.
  1.3568 + *
  1.3569 + *---------------------------------------------------------------------------
  1.3570 + */
  1.3571 +
  1.3572 +EXPORT_C int
  1.3573 +Tcl_GetsObj(chan, objPtr)
  1.3574 +    Tcl_Channel chan;		/* Channel from which to read. */
  1.3575 +    Tcl_Obj *objPtr;		/* The line read will be appended to this
  1.3576 +				 * object as UTF-8 characters. */
  1.3577 +{
  1.3578 +    GetsState gs;
  1.3579 +    Channel *chanPtr = (Channel *) chan;
  1.3580 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.3581 +    ChannelBuffer *bufPtr;
  1.3582 +    int inEofChar, skip, copiedTotal, oldLength, oldFlags, oldRemoved;
  1.3583 +    Tcl_Encoding encoding;
  1.3584 +    char *dst, *dstEnd, *eol, *eof;
  1.3585 +    Tcl_EncodingState oldState;
  1.3586 +
  1.3587 +    /*
  1.3588 +     * This operation should occur at the top of a channel stack.
  1.3589 +     */
  1.3590 +
  1.3591 +    chanPtr = statePtr->topChanPtr;
  1.3592 +
  1.3593 +    if (CheckChannelErrors(statePtr, TCL_READABLE) != 0) {
  1.3594 +	copiedTotal = -1;
  1.3595 +	goto done;
  1.3596 +    }
  1.3597 +
  1.3598 +    bufPtr = statePtr->inQueueHead;
  1.3599 +    encoding = statePtr->encoding;
  1.3600 +
  1.3601 +    /*
  1.3602 +     * Preserved so we can restore the channel's state in case we don't
  1.3603 +     * find a newline in the available input.
  1.3604 +     */
  1.3605 +
  1.3606 +    Tcl_GetStringFromObj(objPtr, &oldLength);
  1.3607 +    oldFlags = statePtr->inputEncodingFlags;
  1.3608 +    oldState = statePtr->inputEncodingState;
  1.3609 +    oldRemoved = BUFFER_PADDING;
  1.3610 +    if (bufPtr != NULL) {
  1.3611 +	oldRemoved = bufPtr->nextRemoved;
  1.3612 +    }
  1.3613 +
  1.3614 +    /*
  1.3615 +     * If there is no encoding, use "iso8859-1" -- Tcl_GetsObj() doesn't
  1.3616 +     * produce ByteArray objects.  To avoid circularity problems,
  1.3617 +     * "iso8859-1" is builtin to Tcl.
  1.3618 +     */
  1.3619 +
  1.3620 +    if (encoding == NULL) {
  1.3621 +	encoding = Tcl_GetEncoding(NULL, "iso8859-1");
  1.3622 +    }
  1.3623 +
  1.3624 +    /*
  1.3625 +     * Object used by FilterInputBytes to keep track of how much data has
  1.3626 +     * been consumed from the channel buffers.
  1.3627 +     */
  1.3628 +
  1.3629 +    gs.objPtr		= objPtr;
  1.3630 +    gs.dstPtr		= &dst;
  1.3631 +    gs.encoding		= encoding;
  1.3632 +    gs.bufPtr		= bufPtr;
  1.3633 +    gs.state		= oldState;
  1.3634 +    gs.rawRead		= 0;
  1.3635 +    gs.bytesWrote	= 0;
  1.3636 +    gs.charsWrote	= 0;
  1.3637 +    gs.totalChars	= 0;
  1.3638 +
  1.3639 +    dst = objPtr->bytes + oldLength;
  1.3640 +    dstEnd = dst;
  1.3641 +
  1.3642 +    skip = 0;
  1.3643 +    eof = NULL;
  1.3644 +    inEofChar = statePtr->inEofChar;
  1.3645 +
  1.3646 +    while (1) {
  1.3647 +	if (dst >= dstEnd) {
  1.3648 +	    if (FilterInputBytes(chanPtr, &gs) != 0) {
  1.3649 +		goto restore;
  1.3650 +	    }
  1.3651 +	    dstEnd = dst + gs.bytesWrote;
  1.3652 +	}
  1.3653 +	
  1.3654 +	/*
  1.3655 +	 * Remember if EOF char is seen, then look for EOL anyhow, because
  1.3656 +	 * the EOL might be before the EOF char.
  1.3657 +	 */
  1.3658 +
  1.3659 +	if (inEofChar != '\0') {
  1.3660 +	    for (eol = dst; eol < dstEnd; eol++) {
  1.3661 +		if (*eol == inEofChar) {
  1.3662 +		    dstEnd = eol;
  1.3663 +		    eof = eol;
  1.3664 +		    break;
  1.3665 +		}
  1.3666 +	    }
  1.3667 +	}
  1.3668 +
  1.3669 +	/*
  1.3670 +	 * On EOL, leave current file position pointing after the EOL, but
  1.3671 +	 * don't store the EOL in the output string.
  1.3672 +	 */
  1.3673 +
  1.3674 +	switch (statePtr->inputTranslation) {
  1.3675 +	    case TCL_TRANSLATE_LF: {
  1.3676 +		for (eol = dst; eol < dstEnd; eol++) {
  1.3677 +		    if (*eol == '\n') {
  1.3678 +			skip = 1;
  1.3679 +			goto goteol;
  1.3680 +		    }
  1.3681 +		}
  1.3682 +		break;
  1.3683 +	    }
  1.3684 +	    case TCL_TRANSLATE_CR: {
  1.3685 +		for (eol = dst; eol < dstEnd; eol++) {
  1.3686 +		    if (*eol == '\r') {
  1.3687 +			skip = 1;
  1.3688 +			goto goteol;
  1.3689 +		    }
  1.3690 +		}
  1.3691 +		break;
  1.3692 +	    }
  1.3693 +	    case TCL_TRANSLATE_CRLF: {
  1.3694 +		for (eol = dst; eol < dstEnd; eol++) {
  1.3695 +		    if (*eol == '\r') {
  1.3696 +			eol++;
  1.3697 +			if (eol >= dstEnd) {
  1.3698 +			    int offset;
  1.3699 +			    
  1.3700 +			    offset = eol - objPtr->bytes;
  1.3701 +			    dst = dstEnd;
  1.3702 +			    if (FilterInputBytes(chanPtr, &gs) != 0) {
  1.3703 +				goto restore;
  1.3704 +			    }
  1.3705 +			    dstEnd = dst + gs.bytesWrote;
  1.3706 +			    eol = objPtr->bytes + offset;
  1.3707 +			    if (eol >= dstEnd) {
  1.3708 +				skip = 0;
  1.3709 +				goto goteol;
  1.3710 +			    }
  1.3711 +			}
  1.3712 +			if (*eol == '\n') {
  1.3713 +			    eol--;
  1.3714 +			    skip = 2;
  1.3715 +			    goto goteol;
  1.3716 +			}
  1.3717 +		    }
  1.3718 +		}
  1.3719 +		break;
  1.3720 +	    }
  1.3721 +	    case TCL_TRANSLATE_AUTO: {
  1.3722 +		eol = dst;
  1.3723 +		skip = 1;
  1.3724 +		if (statePtr->flags & INPUT_SAW_CR) {
  1.3725 +		    statePtr->flags &= ~INPUT_SAW_CR;
  1.3726 +		    if (*eol == '\n') {
  1.3727 +			/*
  1.3728 +			 * Skip the raw bytes that make up the '\n'.
  1.3729 +			 */
  1.3730 +
  1.3731 +			char tmp[1 + TCL_UTF_MAX];
  1.3732 +			int rawRead;
  1.3733 +
  1.3734 +			bufPtr = gs.bufPtr;
  1.3735 +			Tcl_ExternalToUtf(NULL, gs.encoding,
  1.3736 +				bufPtr->buf + bufPtr->nextRemoved,
  1.3737 +				gs.rawRead, statePtr->inputEncodingFlags,
  1.3738 +				&gs.state, tmp, 1 + TCL_UTF_MAX, &rawRead,
  1.3739 +				NULL, NULL);
  1.3740 +			bufPtr->nextRemoved += rawRead;
  1.3741 +			gs.rawRead -= rawRead;
  1.3742 +			gs.bytesWrote--;
  1.3743 +			gs.charsWrote--;
  1.3744 +			memmove(dst, dst + 1, (size_t) (dstEnd - dst));
  1.3745 +			dstEnd--;
  1.3746 +		    }
  1.3747 +		}
  1.3748 +		for (eol = dst; eol < dstEnd; eol++) {
  1.3749 +		    if (*eol == '\r') {
  1.3750 +			eol++;
  1.3751 +			if (eol == dstEnd) {
  1.3752 +			    /*
  1.3753 +			     * If buffer ended on \r, peek ahead to see if a
  1.3754 +			     * \n is available.
  1.3755 +			     */
  1.3756 +
  1.3757 +			    int offset;
  1.3758 +			    
  1.3759 +			    offset = eol - objPtr->bytes;
  1.3760 +			    dst = dstEnd;
  1.3761 +			    PeekAhead(chanPtr, &dstEnd, &gs);
  1.3762 +			    eol = objPtr->bytes + offset;
  1.3763 +			    if (eol >= dstEnd) {
  1.3764 +				eol--;
  1.3765 +				statePtr->flags |= INPUT_SAW_CR;
  1.3766 +				goto goteol;
  1.3767 +			    }
  1.3768 +			}
  1.3769 +			if (*eol == '\n') {
  1.3770 +			    skip++;
  1.3771 +			}
  1.3772 +			eol--;
  1.3773 +			goto goteol;
  1.3774 +		    } else if (*eol == '\n') {
  1.3775 +			goto goteol;
  1.3776 +		    }
  1.3777 +		}
  1.3778 +	    }
  1.3779 +	}
  1.3780 +	if (eof != NULL) {
  1.3781 +	    /*
  1.3782 +	     * EOF character was seen.  On EOF, leave current file position
  1.3783 +	     * pointing at the EOF character, but don't store the EOF
  1.3784 +	     * character in the output string.
  1.3785 +	     */
  1.3786 +
  1.3787 +	    dstEnd = eof;
  1.3788 +	    statePtr->flags |= (CHANNEL_EOF | CHANNEL_STICKY_EOF);
  1.3789 +	    statePtr->inputEncodingFlags |= TCL_ENCODING_END;
  1.3790 +	}
  1.3791 +	if (statePtr->flags & CHANNEL_EOF) {
  1.3792 +	    skip = 0;
  1.3793 +	    eol = dstEnd;
  1.3794 +	    if (eol == objPtr->bytes + oldLength) {
  1.3795 +		/*
  1.3796 +		 * If we didn't append any bytes before encountering EOF,
  1.3797 +		 * caller needs to see -1.
  1.3798 +		 */
  1.3799 +
  1.3800 +		Tcl_SetObjLength(objPtr, oldLength);
  1.3801 +		CommonGetsCleanup(chanPtr, encoding);
  1.3802 +		copiedTotal = -1;
  1.3803 +		goto done;
  1.3804 +	    }
  1.3805 +	    goto goteol;
  1.3806 +	}
  1.3807 +	dst = dstEnd;
  1.3808 +    }
  1.3809 +
  1.3810 +    /*
  1.3811 +     * Found EOL or EOF, but the output buffer may now contain too many
  1.3812 +     * UTF-8 characters.  We need to know how many raw bytes correspond to
  1.3813 +     * the number of UTF-8 characters we want, plus how many raw bytes
  1.3814 +     * correspond to the character(s) making up EOL (if any), so we can
  1.3815 +     * remove the correct number of bytes from the channel buffer.
  1.3816 +     */
  1.3817 +     
  1.3818 +    goteol:
  1.3819 +    bufPtr = gs.bufPtr;
  1.3820 +    statePtr->inputEncodingState = gs.state;
  1.3821 +    Tcl_ExternalToUtf(NULL, gs.encoding, bufPtr->buf + bufPtr->nextRemoved,
  1.3822 +	    gs.rawRead, statePtr->inputEncodingFlags,
  1.3823 +	    &statePtr->inputEncodingState, dst,
  1.3824 +	    eol - dst + skip + TCL_UTF_MAX, &gs.rawRead, NULL,
  1.3825 +	    &gs.charsWrote);
  1.3826 +    bufPtr->nextRemoved += gs.rawRead;
  1.3827 +
  1.3828 +    /*
  1.3829 +     * Recycle all the emptied buffers.
  1.3830 +     */
  1.3831 +
  1.3832 +    Tcl_SetObjLength(objPtr, eol - objPtr->bytes);
  1.3833 +    CommonGetsCleanup(chanPtr, encoding);
  1.3834 +    statePtr->flags &= ~CHANNEL_BLOCKED;
  1.3835 +    copiedTotal = gs.totalChars + gs.charsWrote - skip;
  1.3836 +    goto done;
  1.3837 +
  1.3838 +    /*
  1.3839 +     * Couldn't get a complete line.  This only happens if we get a error
  1.3840 +     * reading from the channel or we are non-blocking and there wasn't
  1.3841 +     * an EOL or EOF in the data available.
  1.3842 +     */
  1.3843 +
  1.3844 +    restore:
  1.3845 +    bufPtr = statePtr->inQueueHead;
  1.3846 +    bufPtr->nextRemoved = oldRemoved;
  1.3847 +
  1.3848 +    for (bufPtr = bufPtr->nextPtr; bufPtr != NULL; bufPtr = bufPtr->nextPtr) {
  1.3849 +	bufPtr->nextRemoved = BUFFER_PADDING;
  1.3850 +    }
  1.3851 +    CommonGetsCleanup(chanPtr, encoding);
  1.3852 +
  1.3853 +    statePtr->inputEncodingState = oldState;
  1.3854 +    statePtr->inputEncodingFlags = oldFlags;
  1.3855 +    Tcl_SetObjLength(objPtr, oldLength);
  1.3856 +
  1.3857 +    /*
  1.3858 +     * We didn't get a complete line so we need to indicate to UpdateInterest
  1.3859 +     * that the gets blocked.  It will wait for more data instead of firing
  1.3860 +     * a timer, avoiding a busy wait.  This is where we are assuming that the
  1.3861 +     * next operation is a gets.  No more file events will be delivered on 
  1.3862 +     * this channel until new data arrives or some operation is performed
  1.3863 +     * on the channel (e.g. gets, read, fconfigure) that changes the blocking
  1.3864 +     * state.  Note that this means a file event will not be delivered even
  1.3865 +     * though a read would be able to consume the buffered data.
  1.3866 +     */
  1.3867 +
  1.3868 +    statePtr->flags |= CHANNEL_NEED_MORE_DATA;
  1.3869 +    copiedTotal = -1;
  1.3870 +
  1.3871 +    done:
  1.3872 +    /*
  1.3873 +     * Update the notifier state so we don't block while there is still
  1.3874 +     * data in the buffers.
  1.3875 +     */
  1.3876 +
  1.3877 +    UpdateInterest(chanPtr);
  1.3878 +    return copiedTotal;
  1.3879 +}
  1.3880 +
  1.3881 +/*
  1.3882 + *---------------------------------------------------------------------------
  1.3883 + *
  1.3884 + * FilterInputBytes --
  1.3885 + *
  1.3886 + *	Helper function for Tcl_GetsObj.  Produces UTF-8 characters from
  1.3887 + *	raw bytes read from the channel.  
  1.3888 + *
  1.3889 + *	Consumes available bytes from channel buffers.  When channel
  1.3890 + *	buffers are exhausted, reads more bytes from channel device into
  1.3891 + *	a new channel buffer.  It is the caller's responsibility to
  1.3892 + *	free the channel buffers that have been exhausted.
  1.3893 + *
  1.3894 + * Results:
  1.3895 + *	The return value is -1 if there was an error reading from the
  1.3896 + *	channel, 0 otherwise.
  1.3897 + *
  1.3898 + * Side effects:
  1.3899 + *	Status object keeps track of how much data from channel buffers
  1.3900 + *	has been consumed and where UTF-8 bytes should be stored.
  1.3901 + *
  1.3902 + *---------------------------------------------------------------------------
  1.3903 + */
  1.3904 + 
  1.3905 +static int
  1.3906 +FilterInputBytes(chanPtr, gsPtr)
  1.3907 +    Channel *chanPtr;		/* Channel to read. */
  1.3908 +    GetsState *gsPtr;		/* Current state of gets operation. */
  1.3909 +{
  1.3910 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.3911 +    ChannelBuffer *bufPtr;
  1.3912 +    char *raw, *rawStart, *rawEnd;
  1.3913 +    char *dst;
  1.3914 +    int offset, toRead, dstNeeded, spaceLeft, result, rawLen, length;
  1.3915 +    Tcl_Obj *objPtr;
  1.3916 +#define ENCODING_LINESIZE   20	/* Lower bound on how many bytes to convert
  1.3917 +				 * at a time.  Since we don't know a priori
  1.3918 +				 * how many bytes of storage this many source
  1.3919 +				 * bytes will use, we actually need at least
  1.3920 +				 * ENCODING_LINESIZE * TCL_MAX_UTF bytes of
  1.3921 +				 * room. */
  1.3922 +
  1.3923 +    objPtr = gsPtr->objPtr;
  1.3924 +
  1.3925 +    /*
  1.3926 +     * Subtract the number of bytes that were removed from channel buffer
  1.3927 +     * during last call.
  1.3928 +     */
  1.3929 +
  1.3930 +    bufPtr = gsPtr->bufPtr;
  1.3931 +    if (bufPtr != NULL) {
  1.3932 +	bufPtr->nextRemoved += gsPtr->rawRead;
  1.3933 +	if (bufPtr->nextRemoved >= bufPtr->nextAdded) {
  1.3934 +	    bufPtr = bufPtr->nextPtr;
  1.3935 +	}
  1.3936 +    }
  1.3937 +    gsPtr->totalChars += gsPtr->charsWrote;
  1.3938 +
  1.3939 +    if ((bufPtr == NULL) || (bufPtr->nextAdded == BUFFER_PADDING)) {
  1.3940 +	/*
  1.3941 +	 * All channel buffers were exhausted and the caller still hasn't
  1.3942 +	 * seen EOL.  Need to read more bytes from the channel device.
  1.3943 +	 * Side effect is to allocate another channel buffer.
  1.3944 +	 */
  1.3945 +
  1.3946 +	read:
  1.3947 +        if (statePtr->flags & CHANNEL_BLOCKED) {
  1.3948 +            if (statePtr->flags & CHANNEL_NONBLOCKING) {
  1.3949 +		gsPtr->charsWrote = 0;
  1.3950 +		gsPtr->rawRead = 0;
  1.3951 +		return -1;
  1.3952 +	    }
  1.3953 +            statePtr->flags &= ~CHANNEL_BLOCKED;
  1.3954 +        }
  1.3955 +	if (GetInput(chanPtr) != 0) {
  1.3956 +	    gsPtr->charsWrote = 0;
  1.3957 +	    gsPtr->rawRead = 0;
  1.3958 +	    return -1;
  1.3959 +	}
  1.3960 +	bufPtr = statePtr->inQueueTail;
  1.3961 +	gsPtr->bufPtr = bufPtr;
  1.3962 +    }
  1.3963 +
  1.3964 +    /*
  1.3965 +     * Convert some of the bytes from the channel buffer to UTF-8.  Space in
  1.3966 +     * objPtr's string rep is used to hold the UTF-8 characters.  Grow the
  1.3967 +     * string rep if we need more space.
  1.3968 +     */
  1.3969 +
  1.3970 +    rawStart = bufPtr->buf + bufPtr->nextRemoved;
  1.3971 +    raw = rawStart;
  1.3972 +    rawEnd = bufPtr->buf + bufPtr->nextAdded;
  1.3973 +    rawLen = rawEnd - rawStart;
  1.3974 +
  1.3975 +    dst = *gsPtr->dstPtr;
  1.3976 +    offset = dst - objPtr->bytes;
  1.3977 +    toRead = ENCODING_LINESIZE;
  1.3978 +    if (toRead > rawLen) {
  1.3979 +	toRead = rawLen;
  1.3980 +    }
  1.3981 +    dstNeeded = toRead * TCL_UTF_MAX + 1;
  1.3982 +    spaceLeft = objPtr->length - offset - TCL_UTF_MAX - 1;
  1.3983 +    if (dstNeeded > spaceLeft) {
  1.3984 +	length = offset * 2;
  1.3985 +	if (offset < dstNeeded) {
  1.3986 +	    length = offset + dstNeeded;
  1.3987 +	}
  1.3988 +	length += TCL_UTF_MAX + 1;
  1.3989 +	Tcl_SetObjLength(objPtr, length);
  1.3990 +	spaceLeft = length - offset;
  1.3991 +	dst = objPtr->bytes + offset;
  1.3992 +	*gsPtr->dstPtr = dst;
  1.3993 +    }
  1.3994 +    gsPtr->state = statePtr->inputEncodingState;
  1.3995 +    result = Tcl_ExternalToUtf(NULL, gsPtr->encoding, raw, rawLen,
  1.3996 +	    statePtr->inputEncodingFlags, &statePtr->inputEncodingState,
  1.3997 +	    dst, spaceLeft, &gsPtr->rawRead, &gsPtr->bytesWrote,
  1.3998 +	    &gsPtr->charsWrote);
  1.3999 +
  1.4000 +    /*
  1.4001 +     * Make sure that if we go through 'gets', that we reset the
  1.4002 +     * TCL_ENCODING_START flag still.  [Bug #523988]
  1.4003 +     */
  1.4004 +    statePtr->inputEncodingFlags &= ~TCL_ENCODING_START;
  1.4005 +
  1.4006 +    if (result == TCL_CONVERT_MULTIBYTE) {
  1.4007 +	/*
  1.4008 +	 * The last few bytes in this channel buffer were the start of a
  1.4009 +	 * multibyte sequence.  If this buffer was full, then move them to
  1.4010 +	 * the next buffer so the bytes will be contiguous.  
  1.4011 +	 */
  1.4012 +
  1.4013 +	ChannelBuffer *nextPtr;
  1.4014 +	int extra;
  1.4015 +	
  1.4016 +	nextPtr = bufPtr->nextPtr;
  1.4017 +	if (bufPtr->nextAdded < bufPtr->bufLength) {
  1.4018 +	    if (gsPtr->rawRead > 0) {
  1.4019 +		/*
  1.4020 +		 * Some raw bytes were converted to UTF-8.  Fall through,
  1.4021 +		 * returning those UTF-8 characters because a EOL might be
  1.4022 +		 * present in them.
  1.4023 +		 */
  1.4024 +	    } else if (statePtr->flags & CHANNEL_EOF) {
  1.4025 +		/*
  1.4026 +		 * There was a partial character followed by EOF on the
  1.4027 +		 * device.  Fall through, returning that nothing was found.
  1.4028 +		 */
  1.4029 +
  1.4030 +		bufPtr->nextRemoved = bufPtr->nextAdded;
  1.4031 +	    } else {
  1.4032 +		/*
  1.4033 +		 * There are no more cached raw bytes left.  See if we can
  1.4034 +		 * get some more.
  1.4035 +		 */
  1.4036 +
  1.4037 +		goto read;
  1.4038 +	    }
  1.4039 +	} else {
  1.4040 +	    if (nextPtr == NULL) {
  1.4041 +		nextPtr = AllocChannelBuffer(statePtr->bufSize);
  1.4042 +		bufPtr->nextPtr = nextPtr;
  1.4043 +		statePtr->inQueueTail = nextPtr;
  1.4044 +	    }
  1.4045 +	    extra = rawLen - gsPtr->rawRead;
  1.4046 +	    memcpy((VOID *) (nextPtr->buf + BUFFER_PADDING - extra),
  1.4047 +		    (VOID *) (raw + gsPtr->rawRead), (size_t) extra);
  1.4048 +	    nextPtr->nextRemoved -= extra;
  1.4049 +	    bufPtr->nextAdded -= extra;
  1.4050 +	}
  1.4051 +    }
  1.4052 +
  1.4053 +    gsPtr->bufPtr = bufPtr;
  1.4054 +    return 0;
  1.4055 +}
  1.4056 +
  1.4057 +/*
  1.4058 + *---------------------------------------------------------------------------
  1.4059 + *
  1.4060 + * PeekAhead --
  1.4061 + *
  1.4062 + *	Helper function used by Tcl_GetsObj().  Called when we've seen a
  1.4063 + *	\r at the end of the UTF-8 string and want to look ahead one
  1.4064 + *	character to see if it is a \n.
  1.4065 + *
  1.4066 + * Results:
  1.4067 + *	*gsPtr->dstPtr is filled with a pointer to the start of the range of
  1.4068 + *	UTF-8 characters that were found by peeking and *dstEndPtr is filled
  1.4069 + *	with a pointer to the bytes just after the end of the range.
  1.4070 + *
  1.4071 + * Side effects:
  1.4072 + *	If no more raw bytes were available in one of the channel buffers,
  1.4073 + *	tries to perform a non-blocking read to get more bytes from the
  1.4074 + *	channel device.
  1.4075 + *
  1.4076 + *---------------------------------------------------------------------------
  1.4077 + */
  1.4078 +
  1.4079 +static void
  1.4080 +PeekAhead(chanPtr, dstEndPtr, gsPtr)
  1.4081 +    Channel *chanPtr;		/* The channel to read. */
  1.4082 +    char **dstEndPtr;		/* Filled with pointer to end of new range
  1.4083 +				 * of UTF-8 characters. */
  1.4084 +    GetsState *gsPtr;		/* Current state of gets operation. */
  1.4085 +{
  1.4086 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.4087 +    ChannelBuffer *bufPtr;
  1.4088 +    Tcl_DriverBlockModeProc *blockModeProc;
  1.4089 +    int bytesLeft;
  1.4090 +
  1.4091 +    bufPtr = gsPtr->bufPtr;
  1.4092 +
  1.4093 +    /*
  1.4094 +     * If there's any more raw input that's still buffered, we'll peek into
  1.4095 +     * that.  Otherwise, only get more data from the channel driver if it
  1.4096 +     * looks like there might actually be more data.  The assumption is that
  1.4097 +     * if the channel buffer is filled right up to the end, then there
  1.4098 +     * might be more data to read.
  1.4099 +     */
  1.4100 +
  1.4101 +    blockModeProc = NULL;
  1.4102 +    if (bufPtr->nextPtr == NULL) {
  1.4103 +	bytesLeft = bufPtr->nextAdded - (bufPtr->nextRemoved + gsPtr->rawRead);
  1.4104 +	if (bytesLeft == 0) {
  1.4105 +	    if (bufPtr->nextAdded < bufPtr->bufLength) {
  1.4106 +		/*
  1.4107 +		 * Don't peek ahead if last read was short read.
  1.4108 +		 */
  1.4109 +		 
  1.4110 +		goto cleanup;
  1.4111 +	    }
  1.4112 +	    if ((statePtr->flags & CHANNEL_NONBLOCKING) == 0) {
  1.4113 +		blockModeProc = Tcl_ChannelBlockModeProc(chanPtr->typePtr);
  1.4114 +		if (blockModeProc == NULL) {
  1.4115 +		    /*
  1.4116 +		     * Don't peek ahead if cannot set non-blocking mode.
  1.4117 +		     */
  1.4118 +
  1.4119 +		    goto cleanup;
  1.4120 +		}
  1.4121 +		StackSetBlockMode(chanPtr, TCL_MODE_NONBLOCKING);
  1.4122 +	    }
  1.4123 +	}
  1.4124 +    }
  1.4125 +    if (FilterInputBytes(chanPtr, gsPtr) == 0) {
  1.4126 +	*dstEndPtr = *gsPtr->dstPtr + gsPtr->bytesWrote;
  1.4127 +    }
  1.4128 +    if (blockModeProc != NULL) {
  1.4129 +	StackSetBlockMode(chanPtr, TCL_MODE_BLOCKING);
  1.4130 +    }
  1.4131 +    return;
  1.4132 +
  1.4133 +    cleanup:
  1.4134 +    bufPtr->nextRemoved += gsPtr->rawRead;
  1.4135 +    gsPtr->rawRead = 0;
  1.4136 +    gsPtr->totalChars += gsPtr->charsWrote;
  1.4137 +    gsPtr->bytesWrote = 0;
  1.4138 +    gsPtr->charsWrote = 0;
  1.4139 +}
  1.4140 +
  1.4141 +/*
  1.4142 + *---------------------------------------------------------------------------
  1.4143 + *
  1.4144 + * CommonGetsCleanup --
  1.4145 + *
  1.4146 + *	Helper function for Tcl_GetsObj() to restore the channel after
  1.4147 + *	a "gets" operation.
  1.4148 + *
  1.4149 + * Results:
  1.4150 + *	None.
  1.4151 + *
  1.4152 + * Side effects:
  1.4153 + *	Encoding may be freed.
  1.4154 + *
  1.4155 + *---------------------------------------------------------------------------
  1.4156 + */
  1.4157 + 
  1.4158 +static void
  1.4159 +CommonGetsCleanup(chanPtr, encoding)
  1.4160 +    Channel *chanPtr;
  1.4161 +    Tcl_Encoding encoding;
  1.4162 +{
  1.4163 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.4164 +    ChannelBuffer *bufPtr, *nextPtr;
  1.4165 +    
  1.4166 +    bufPtr = statePtr->inQueueHead;
  1.4167 +    for ( ; bufPtr != NULL; bufPtr = nextPtr) {
  1.4168 +	nextPtr = bufPtr->nextPtr;
  1.4169 +	if (bufPtr->nextRemoved < bufPtr->nextAdded) {
  1.4170 +	    break;
  1.4171 +	}
  1.4172 +	RecycleBuffer(statePtr, bufPtr, 0);
  1.4173 +    }
  1.4174 +    statePtr->inQueueHead = bufPtr;
  1.4175 +    if (bufPtr == NULL) {
  1.4176 +	statePtr->inQueueTail = NULL;
  1.4177 +    } else {
  1.4178 +	/*
  1.4179 +	 * If any multi-byte characters were split across channel buffer
  1.4180 +	 * boundaries, the split-up bytes were moved to the next channel
  1.4181 +	 * buffer by FilterInputBytes().  Move the bytes back to their
  1.4182 +	 * original buffer because the caller could change the channel's
  1.4183 +	 * encoding which could change the interpretation of whether those
  1.4184 +	 * bytes really made up multi-byte characters after all.
  1.4185 +	 */
  1.4186 +	 
  1.4187 +	nextPtr = bufPtr->nextPtr;
  1.4188 +	for ( ; nextPtr != NULL; nextPtr = bufPtr->nextPtr) {
  1.4189 +	    int extra;
  1.4190 +
  1.4191 +	    extra = bufPtr->bufLength - bufPtr->nextAdded;
  1.4192 +	    if (extra > 0) {
  1.4193 +		memcpy((VOID *) (bufPtr->buf + bufPtr->nextAdded),
  1.4194 +			(VOID *) (nextPtr->buf + BUFFER_PADDING - extra),
  1.4195 +			(size_t) extra);
  1.4196 +		bufPtr->nextAdded += extra;
  1.4197 +		nextPtr->nextRemoved = BUFFER_PADDING;
  1.4198 +	    }
  1.4199 +	    bufPtr = nextPtr;
  1.4200 +	}
  1.4201 +    }
  1.4202 +    if (statePtr->encoding == NULL) {
  1.4203 +	Tcl_FreeEncoding(encoding);
  1.4204 +    }
  1.4205 +}
  1.4206 +
  1.4207 +/*
  1.4208 + *----------------------------------------------------------------------
  1.4209 + *
  1.4210 + * Tcl_Read --
  1.4211 + *
  1.4212 + *	Reads a given number of bytes from a channel.  EOL and EOF
  1.4213 + *	translation is done on the bytes being read, so the the number
  1.4214 + *	of bytes consumed from the channel may not be equal to the
  1.4215 + *	number of bytes stored in the destination buffer.
  1.4216 + *
  1.4217 + *	No encoding conversions are applied to the bytes being read.
  1.4218 + *
  1.4219 + * Results:
  1.4220 + *	The number of bytes read, or -1 on error. Use Tcl_GetErrno()
  1.4221 + *	to retrieve the error code for the error that occurred.
  1.4222 + *
  1.4223 + * Side effects:
  1.4224 + *	May cause input to be buffered.
  1.4225 + *
  1.4226 + *----------------------------------------------------------------------
  1.4227 + */
  1.4228 +
  1.4229 +EXPORT_C int
  1.4230 +Tcl_Read(chan, dst, bytesToRead)
  1.4231 +    Tcl_Channel chan;		/* The channel from which to read. */
  1.4232 +    char *dst;			/* Where to store input read. */
  1.4233 +    int bytesToRead;		/* Maximum number of bytes to read. */
  1.4234 +{
  1.4235 +    Channel *chanPtr = (Channel *) chan;		
  1.4236 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.4237 +
  1.4238 +    /*
  1.4239 +     * This operation should occur at the top of a channel stack.
  1.4240 +     */
  1.4241 +
  1.4242 +    chanPtr = statePtr->topChanPtr;
  1.4243 +
  1.4244 +    if (CheckChannelErrors(statePtr, TCL_READABLE) != 0) {
  1.4245 +	return -1;
  1.4246 +    }
  1.4247 +
  1.4248 +    return DoRead(chanPtr, dst, bytesToRead);
  1.4249 +}
  1.4250 +
  1.4251 +/*
  1.4252 + *----------------------------------------------------------------------
  1.4253 + *
  1.4254 + * Tcl_ReadRaw --
  1.4255 + *
  1.4256 + *	Reads a given number of bytes from a channel.  EOL and EOF
  1.4257 + *	translation is done on the bytes being read, so the the number
  1.4258 + *	of bytes consumed from the channel may not be equal to the
  1.4259 + *	number of bytes stored in the destination buffer.
  1.4260 + *
  1.4261 + *	No encoding conversions are applied to the bytes being read.
  1.4262 + *
  1.4263 + * Results:
  1.4264 + *	The number of bytes read, or -1 on error. Use Tcl_GetErrno()
  1.4265 + *	to retrieve the error code for the error that occurred.
  1.4266 + *
  1.4267 + * Side effects:
  1.4268 + *	May cause input to be buffered.
  1.4269 + *
  1.4270 + *----------------------------------------------------------------------
  1.4271 + */
  1.4272 +
  1.4273 +EXPORT_C int
  1.4274 +Tcl_ReadRaw(chan, bufPtr, bytesToRead)
  1.4275 +    Tcl_Channel chan;		/* The channel from which to read. */
  1.4276 +    char *bufPtr;		/* Where to store input read. */
  1.4277 +    int bytesToRead;		/* Maximum number of bytes to read. */
  1.4278 +{
  1.4279 +    Channel *chanPtr = (Channel *) chan;		
  1.4280 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.4281 +    int nread, result;
  1.4282 +    int copied, copiedNow;
  1.4283 +
  1.4284 +    /*
  1.4285 +     * The check below does too much because it will reject a call to this
  1.4286 +     * function with a channel which is part of an 'fcopy'. But we have to
  1.4287 +     * allow this here or else the chaining in the transformation drivers
  1.4288 +     * will fail with 'file busy' error instead of retrieving and
  1.4289 +     * transforming the data to copy.
  1.4290 +     *
  1.4291 +     * We let the check procedure now believe that there is no fcopy in
  1.4292 +     * progress. A better solution than this might be an additional flag
  1.4293 +     * argument to switch off specific checks.
  1.4294 +     */
  1.4295 +
  1.4296 +    if (CheckChannelErrors(statePtr, TCL_READABLE | CHANNEL_RAW_MODE) != 0) {
  1.4297 +	return -1;
  1.4298 +    }
  1.4299 +
  1.4300 +    /*
  1.4301 +     * Check for information in the push-back buffers. If there is
  1.4302 +     * some, use it. Go to the driver only if there is none (anymore)
  1.4303 +     * and the caller requests more bytes.
  1.4304 +     */
  1.4305 +
  1.4306 +    for (copied = 0; copied < bytesToRead; copied += copiedNow) {
  1.4307 +        copiedNow = CopyBuffer(chanPtr, bufPtr + copied,
  1.4308 +                bytesToRead - copied);
  1.4309 +        if (copiedNow == 0) {
  1.4310 +            if (statePtr->flags & CHANNEL_EOF) {
  1.4311 +		goto done;
  1.4312 +            }
  1.4313 +            if (statePtr->flags & CHANNEL_BLOCKED) {
  1.4314 +                if (statePtr->flags & CHANNEL_NONBLOCKING) {
  1.4315 +		    goto done;
  1.4316 +                }
  1.4317 +                statePtr->flags &= (~(CHANNEL_BLOCKED));
  1.4318 +            }
  1.4319 +
  1.4320 +#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
  1.4321 +	    /* [SF Tcl Bug 943274]. Better emulation of non-blocking
  1.4322 +	     * channels for channels without BlockModeProc, by keeping
  1.4323 +	     * track of true fileevents generated by the OS == Data
  1.4324 +	     * waiting and reading if and only if we are sure to have
  1.4325 +	     * data.
  1.4326 +	     */
  1.4327 +
  1.4328 +	    if ((statePtr->flags & CHANNEL_NONBLOCKING) &&
  1.4329 +		(Tcl_ChannelBlockModeProc(chanPtr->typePtr) == NULL) &&
  1.4330 +		!(statePtr->flags & CHANNEL_HAS_MORE_DATA)) {
  1.4331 +
  1.4332 +	        /* We bypass the driver, it would block, as no data is available */
  1.4333 +	        nread  = -1;
  1.4334 +	        result = EWOULDBLOCK;
  1.4335 +	    } else {
  1.4336 +#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
  1.4337 +	      /*
  1.4338 +	       * Now go to the driver to get as much as is possible to
  1.4339 +	       * fill the remaining request. Do all the error handling
  1.4340 +	       * by ourselves.  The code was stolen from 'GetInput' and
  1.4341 +	       * slightly adapted (different return value here).
  1.4342 +	       *
  1.4343 +	       * The case of 'bytesToRead == 0' at this point cannot happen.
  1.4344 +	       */
  1.4345 +
  1.4346 +	      nread = (chanPtr->typePtr->inputProc)(chanPtr->instanceData,
  1.4347 +			  bufPtr + copied, bytesToRead - copied, &result);
  1.4348 +#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
  1.4349 +	    }
  1.4350 +#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
  1.4351 +	    if (nread > 0) {
  1.4352 +	        /*
  1.4353 +		 * If we get a short read, signal up that we may be
  1.4354 +		 * BLOCKED. We should avoid calling the driver because
  1.4355 +		 * on some platforms we will block in the low level
  1.4356 +		 * reading code even though the channel is set into
  1.4357 +		 * nonblocking mode.
  1.4358 +		 */
  1.4359 +            
  1.4360 +	        if (nread < (bytesToRead - copied)) {
  1.4361 +		    statePtr->flags |= CHANNEL_BLOCKED;
  1.4362 +		}
  1.4363 +
  1.4364 +#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
  1.4365 +	        if (nread <= (bytesToRead - copied)) {
  1.4366 +		    /* [SF Tcl Bug 943274] We have read the available
  1.4367 +		     * data, clear flag */
  1.4368 +		    statePtr->flags &= ~CHANNEL_HAS_MORE_DATA;
  1.4369 +		}
  1.4370 +#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
  1.4371 +	    } else if (nread == 0) {
  1.4372 +	        statePtr->flags |= CHANNEL_EOF;
  1.4373 +		statePtr->inputEncodingFlags |= TCL_ENCODING_END;
  1.4374 +	    } else if (nread < 0) {
  1.4375 +	        if ((result == EWOULDBLOCK) || (result == EAGAIN)) {
  1.4376 +		    if (copied > 0) {
  1.4377 +		      /*
  1.4378 +		       * Information that was copied earlier has precedence
  1.4379 +		       * over EAGAIN/WOULDBLOCK handling.
  1.4380 +		       */
  1.4381 +		      return copied;
  1.4382 +		    }
  1.4383 +
  1.4384 +		    statePtr->flags |= CHANNEL_BLOCKED;
  1.4385 +		    result = EAGAIN;
  1.4386 +		}
  1.4387 +
  1.4388 +		Tcl_SetErrno(result);
  1.4389 +		return -1;
  1.4390 +	    } 
  1.4391 +
  1.4392 +	    return copied + nread;
  1.4393 +        }
  1.4394 +    }
  1.4395 +
  1.4396 +done:
  1.4397 +    return copied;
  1.4398 +}
  1.4399 +
  1.4400 +/*
  1.4401 + *---------------------------------------------------------------------------
  1.4402 + *
  1.4403 + * Tcl_ReadChars --
  1.4404 + *
  1.4405 + *	Reads from the channel until the requested number of characters
  1.4406 + *	have been seen, EOF is seen, or the channel would block.  EOL
  1.4407 + *	and EOF translation is done.  If reading binary data, the raw
  1.4408 + *	bytes are wrapped in a Tcl byte array object.  Otherwise, the raw
  1.4409 + *	bytes are converted to UTF-8 using the channel's current encoding
  1.4410 + *	and stored in a Tcl string object.
  1.4411 + *
  1.4412 + * Results:
  1.4413 + *	The number of characters read, or -1 on error. Use Tcl_GetErrno()
  1.4414 + *	to retrieve the error code for the error that occurred.
  1.4415 + *
  1.4416 + * Side effects:
  1.4417 + *	May cause input to be buffered.
  1.4418 + *
  1.4419 + *---------------------------------------------------------------------------
  1.4420 + */
  1.4421 + 
  1.4422 +EXPORT_C int
  1.4423 +Tcl_ReadChars(chan, objPtr, toRead, appendFlag)
  1.4424 +    Tcl_Channel chan;		/* The channel to read. */
  1.4425 +    Tcl_Obj *objPtr;		/* Input data is stored in this object. */
  1.4426 +    int toRead;			/* Maximum number of characters to store,
  1.4427 +				 * or -1 to read all available data (up to EOF
  1.4428 +				 * or when channel blocks). */
  1.4429 +    int appendFlag;		/* If non-zero, data read from the channel
  1.4430 +				 * will be appended to the object.  Otherwise,
  1.4431 +				 * the data will replace the existing contents
  1.4432 +				 * of the object. */
  1.4433 +
  1.4434 +{
  1.4435 +    Channel*      chanPtr  = (Channel *) chan;
  1.4436 +    ChannelState* statePtr = chanPtr->state;	/* state info for channel */
  1.4437 +    
  1.4438 +    /*
  1.4439 +     * This operation should occur at the top of a channel stack.
  1.4440 +     */
  1.4441 +
  1.4442 +    chanPtr = statePtr->topChanPtr;
  1.4443 +
  1.4444 +    if (CheckChannelErrors(statePtr, TCL_READABLE) != 0) {
  1.4445 +        /*
  1.4446 +	 * Update the notifier state so we don't block while there is still
  1.4447 +	 * data in the buffers.
  1.4448 +	 */
  1.4449 +        UpdateInterest(chanPtr);
  1.4450 +	return -1;
  1.4451 +    }
  1.4452 +
  1.4453 +    return DoReadChars (chanPtr, objPtr, toRead, appendFlag);
  1.4454 +}
  1.4455 +/*
  1.4456 + *---------------------------------------------------------------------------
  1.4457 + *
  1.4458 + * DoReadChars --
  1.4459 + *
  1.4460 + *	Reads from the channel until the requested number of characters
  1.4461 + *	have been seen, EOF is seen, or the channel would block.  EOL
  1.4462 + *	and EOF translation is done.  If reading binary data, the raw
  1.4463 + *	bytes are wrapped in a Tcl byte array object.  Otherwise, the raw
  1.4464 + *	bytes are converted to UTF-8 using the channel's current encoding
  1.4465 + *	and stored in a Tcl string object.
  1.4466 + *
  1.4467 + * Results:
  1.4468 + *	The number of characters read, or -1 on error. Use Tcl_GetErrno()
  1.4469 + *	to retrieve the error code for the error that occurred.
  1.4470 + *
  1.4471 + * Side effects:
  1.4472 + *	May cause input to be buffered.
  1.4473 + *
  1.4474 + *---------------------------------------------------------------------------
  1.4475 + */
  1.4476 + 
  1.4477 +static int
  1.4478 +DoReadChars(chanPtr, objPtr, toRead, appendFlag)
  1.4479 +    Channel* chanPtr;		/* The channel to read. */
  1.4480 +    Tcl_Obj *objPtr;		/* Input data is stored in this object. */
  1.4481 +    int toRead;			/* Maximum number of characters to store,
  1.4482 +				 * or -1 to read all available data (up to EOF
  1.4483 +				 * or when channel blocks). */
  1.4484 +    int appendFlag;		/* If non-zero, data read from the channel
  1.4485 +				 * will be appended to the object.  Otherwise,
  1.4486 +				 * the data will replace the existing contents
  1.4487 +				 * of the object. */
  1.4488 +
  1.4489 +{
  1.4490 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.4491 +    ChannelBuffer *bufPtr;
  1.4492 +    int offset, factor, copied, copiedNow, result;
  1.4493 +    Tcl_Encoding encoding;
  1.4494 +#define UTF_EXPANSION_FACTOR	1024
  1.4495 +
  1.4496 +    /*
  1.4497 +     * This operation should occur at the top of a channel stack.
  1.4498 +     */
  1.4499 +
  1.4500 +    chanPtr  = statePtr->topChanPtr;
  1.4501 +    encoding = statePtr->encoding;
  1.4502 +    factor   = UTF_EXPANSION_FACTOR;
  1.4503 +
  1.4504 +    if (appendFlag == 0) {
  1.4505 +	if (encoding == NULL) {
  1.4506 +	    Tcl_SetByteArrayLength(objPtr, 0);
  1.4507 +	} else {
  1.4508 +	    Tcl_SetObjLength(objPtr, 0);
  1.4509 +	    /* 
  1.4510 +	     * We're going to access objPtr->bytes directly, so
  1.4511 +	     * we must ensure that this is actually a string
  1.4512 +	     * object (otherwise it might have been pure Unicode).
  1.4513 +	     */
  1.4514 +	    Tcl_GetString(objPtr);
  1.4515 +	}
  1.4516 +	offset = 0;
  1.4517 +    } else {
  1.4518 +	if (encoding == NULL) {
  1.4519 +	    Tcl_GetByteArrayFromObj(objPtr, &offset);
  1.4520 +	} else {
  1.4521 +	    Tcl_GetStringFromObj(objPtr, &offset);
  1.4522 +	}
  1.4523 +    }
  1.4524 +
  1.4525 +    for (copied = 0; (unsigned) toRead > 0; ) {
  1.4526 +	copiedNow = -1;
  1.4527 +	if (statePtr->inQueueHead != NULL) {
  1.4528 +	    if (encoding == NULL) {
  1.4529 +		copiedNow = ReadBytes(statePtr, objPtr, toRead, &offset);
  1.4530 +	    } else {
  1.4531 +		copiedNow = ReadChars(statePtr, objPtr, toRead, &offset,
  1.4532 +			&factor);
  1.4533 +	    }
  1.4534 +
  1.4535 +	    /*
  1.4536 +	     * If the current buffer is empty recycle it.
  1.4537 +	     */
  1.4538 +
  1.4539 +	    bufPtr = statePtr->inQueueHead;
  1.4540 +	    if (bufPtr->nextRemoved == bufPtr->nextAdded) {
  1.4541 +		ChannelBuffer *nextPtr;
  1.4542 +
  1.4543 +		nextPtr = bufPtr->nextPtr;
  1.4544 +		RecycleBuffer(statePtr, bufPtr, 0);
  1.4545 +		statePtr->inQueueHead = nextPtr;
  1.4546 +		if (nextPtr == NULL) {
  1.4547 +		    statePtr->inQueueTail = NULL;
  1.4548 +		}
  1.4549 +	    }
  1.4550 +	}
  1.4551 +	if (copiedNow < 0) {
  1.4552 +	    if (statePtr->flags & CHANNEL_EOF) {
  1.4553 +		break;
  1.4554 +	    }
  1.4555 +	    if (statePtr->flags & CHANNEL_BLOCKED) {
  1.4556 +		if (statePtr->flags & CHANNEL_NONBLOCKING) {
  1.4557 +		    break;
  1.4558 +		}
  1.4559 +		statePtr->flags &= ~CHANNEL_BLOCKED;
  1.4560 +	    }
  1.4561 +	    result = GetInput(chanPtr);
  1.4562 +	    if (result != 0) {
  1.4563 +		if (result == EAGAIN) {
  1.4564 +		    break;
  1.4565 +		}
  1.4566 +		copied = -1;
  1.4567 +		goto done;
  1.4568 +	    }
  1.4569 +	} else {
  1.4570 +	    copied += copiedNow;
  1.4571 +	    toRead -= copiedNow;
  1.4572 +	}
  1.4573 +    }
  1.4574 +    statePtr->flags &= ~CHANNEL_BLOCKED;
  1.4575 +    if (encoding == NULL) {
  1.4576 +	Tcl_SetByteArrayLength(objPtr, offset);
  1.4577 +    } else {
  1.4578 +	Tcl_SetObjLength(objPtr, offset);
  1.4579 +    }
  1.4580 +
  1.4581 +    done:
  1.4582 +    /*
  1.4583 +     * Update the notifier state so we don't block while there is still
  1.4584 +     * data in the buffers.
  1.4585 +     */
  1.4586 +
  1.4587 +    UpdateInterest(chanPtr);
  1.4588 +    return copied;
  1.4589 +}
  1.4590 +/*
  1.4591 + *---------------------------------------------------------------------------
  1.4592 + *
  1.4593 + * ReadBytes --
  1.4594 + *
  1.4595 + *	Reads from the channel until the requested number of bytes have
  1.4596 + *	been seen, EOF is seen, or the channel would block.  Bytes from
  1.4597 + *	the channel are stored in objPtr as a ByteArray object.  EOL
  1.4598 + *	and EOF translation are done.
  1.4599 + *
  1.4600 + *	'bytesToRead' can safely be a very large number because
  1.4601 + *	space is only allocated to hold data read from the channel
  1.4602 + *	as needed.
  1.4603 + *
  1.4604 + * Results:
  1.4605 + *	The return value is the number of bytes appended to the object
  1.4606 + *	and *offsetPtr is filled with the total number of bytes in the
  1.4607 + *	object (greater than the return value if there were already bytes
  1.4608 + *	in the object).
  1.4609 + *
  1.4610 + * Side effects:
  1.4611 + *	None.
  1.4612 + *
  1.4613 + *---------------------------------------------------------------------------
  1.4614 + */
  1.4615 +
  1.4616 +static int
  1.4617 +ReadBytes(statePtr, objPtr, bytesToRead, offsetPtr)
  1.4618 +    ChannelState *statePtr;	/* State of the channel to read. */
  1.4619 +    Tcl_Obj *objPtr;		/* Input data is appended to this ByteArray
  1.4620 +				 * object.  Its length is how much space
  1.4621 +				 * has been allocated to hold data, not how
  1.4622 +				 * many bytes of data have been stored in the
  1.4623 +				 * object. */
  1.4624 +    int bytesToRead;		/* Maximum number of bytes to store,
  1.4625 +				 * or < 0 to get all available bytes.
  1.4626 +				 * Bytes are obtained from the first
  1.4627 +				 * buffer in the queue -- even if this number
  1.4628 +				 * is larger than the number of bytes
  1.4629 +				 * available in the first buffer, only the
  1.4630 +				 * bytes from the first buffer are
  1.4631 +				 * returned. */
  1.4632 +    int *offsetPtr;		/* On input, contains how many bytes of
  1.4633 +				 * objPtr have been used to hold data.  On
  1.4634 +				 * output, filled with how many bytes are now
  1.4635 +				 * being used. */
  1.4636 +{
  1.4637 +    int toRead, srcLen, offset, length, srcRead, dstWrote;
  1.4638 +    ChannelBuffer *bufPtr;
  1.4639 +    char *src, *dst;
  1.4640 +
  1.4641 +    offset = *offsetPtr;
  1.4642 +
  1.4643 +    bufPtr = statePtr->inQueueHead; 
  1.4644 +    src = bufPtr->buf + bufPtr->nextRemoved;
  1.4645 +    srcLen = bufPtr->nextAdded - bufPtr->nextRemoved;
  1.4646 +
  1.4647 +    toRead = bytesToRead;
  1.4648 +    if ((unsigned) toRead > (unsigned) srcLen) {
  1.4649 +	toRead = srcLen;
  1.4650 +    }
  1.4651 +
  1.4652 +    dst = (char *) Tcl_GetByteArrayFromObj(objPtr, &length);
  1.4653 +    if (toRead > length - offset - 1) {
  1.4654 +	/*
  1.4655 +	 * Double the existing size of the object or make enough room to
  1.4656 +	 * hold all the characters we may get from the source buffer,
  1.4657 +	 * whichever is larger.
  1.4658 +	 */
  1.4659 +
  1.4660 +	length = offset * 2;
  1.4661 +	if (offset < toRead) {
  1.4662 +	    length = offset + toRead + 1;
  1.4663 +	}
  1.4664 +	dst = (char *) Tcl_SetByteArrayLength(objPtr, length);
  1.4665 +    }
  1.4666 +    dst += offset;
  1.4667 +
  1.4668 +    if (statePtr->flags & INPUT_NEED_NL) {
  1.4669 +	statePtr->flags &= ~INPUT_NEED_NL;
  1.4670 +	if ((srcLen == 0) || (*src != '\n')) {
  1.4671 +	    *dst = '\r';
  1.4672 +	    *offsetPtr += 1;
  1.4673 +	    return 1;
  1.4674 +	}
  1.4675 +	*dst++ = '\n';
  1.4676 +	src++;
  1.4677 +	srcLen--;
  1.4678 +	toRead--;
  1.4679 +    }
  1.4680 +
  1.4681 +    srcRead = srcLen;
  1.4682 +    dstWrote = toRead;
  1.4683 +    if (TranslateInputEOL(statePtr, dst, src, &dstWrote, &srcRead) != 0) {
  1.4684 +	if (dstWrote == 0) {
  1.4685 +	    return -1;
  1.4686 +	}
  1.4687 +    }
  1.4688 +    bufPtr->nextRemoved += srcRead;
  1.4689 +    *offsetPtr += dstWrote;
  1.4690 +    return dstWrote;
  1.4691 +}
  1.4692 +
  1.4693 +/*
  1.4694 + *---------------------------------------------------------------------------
  1.4695 + *
  1.4696 + * ReadChars --
  1.4697 + *
  1.4698 + *	Reads from the channel until the requested number of UTF-8
  1.4699 + *	characters have been seen, EOF is seen, or the channel would
  1.4700 + *	block.  Raw bytes from the channel are converted to UTF-8
  1.4701 + *	and stored in objPtr.  EOL and EOF translation is done.
  1.4702 + *
  1.4703 + *	'charsToRead' can safely be a very large number because
  1.4704 + *	space is only allocated to hold data read from the channel
  1.4705 + *	as needed.
  1.4706 + *
  1.4707 + * Results:
  1.4708 + *	The return value is the number of characters appended to
  1.4709 + *	the object, *offsetPtr is filled with the number of bytes that
  1.4710 + *	were appended, and *factorPtr is filled with the expansion
  1.4711 + *	factor used to guess how many bytes of UTF-8 to allocate to
  1.4712 + *	hold N source bytes.
  1.4713 + *
  1.4714 + * Side effects:
  1.4715 + *	None.
  1.4716 + *
  1.4717 + *---------------------------------------------------------------------------
  1.4718 + */
  1.4719 +
  1.4720 +static int
  1.4721 +ReadChars(statePtr, objPtr, charsToRead, offsetPtr, factorPtr)
  1.4722 +    ChannelState *statePtr;	/* State of channel to read. */
  1.4723 +    Tcl_Obj *objPtr;		/* Input data is appended to this object.
  1.4724 +				 * objPtr->length is how much space has been
  1.4725 +				 * allocated to hold data, not how many bytes
  1.4726 +				 * of data have been stored in the object. */
  1.4727 +    int charsToRead;		/* Maximum number of characters to store,
  1.4728 +				 * or -1 to get all available characters.
  1.4729 +				 * Characters are obtained from the first
  1.4730 +				 * buffer in the queue -- even if this number
  1.4731 +				 * is larger than the number of characters
  1.4732 +				 * available in the first buffer, only the
  1.4733 +				 * characters from the first buffer are
  1.4734 +				 * returned. */
  1.4735 +    int *offsetPtr;		/* On input, contains how many bytes of
  1.4736 +				 * objPtr have been used to hold data.  On
  1.4737 +				 * output, filled with how many bytes are now
  1.4738 +				 * being used. */
  1.4739 +    int *factorPtr;		/* On input, contains a guess of how many
  1.4740 +				 * bytes need to be allocated to hold the
  1.4741 +				 * result of converting N source bytes to
  1.4742 +				 * UTF-8.  On output, contains another guess
  1.4743 +				 * based on the data seen so far. */
  1.4744 +{
  1.4745 +    int toRead, factor, offset, spaceLeft, length, srcLen, dstNeeded;
  1.4746 +    int srcRead, dstWrote, numChars, dstRead;
  1.4747 +    ChannelBuffer *bufPtr;
  1.4748 +    char *src, *dst;
  1.4749 +    Tcl_EncodingState oldState;
  1.4750 +    int encEndFlagSuppressed = 0;
  1.4751 +
  1.4752 +    factor = *factorPtr;
  1.4753 +    offset = *offsetPtr;
  1.4754 +
  1.4755 +    bufPtr = statePtr->inQueueHead; 
  1.4756 +    src    = bufPtr->buf + bufPtr->nextRemoved;
  1.4757 +    srcLen = bufPtr->nextAdded - bufPtr->nextRemoved;
  1.4758 +
  1.4759 +    toRead = charsToRead;
  1.4760 +    if ((unsigned)toRead > (unsigned)srcLen) {
  1.4761 +	toRead = srcLen;
  1.4762 +    }
  1.4763 +
  1.4764 +    /*
  1.4765 +     * 'factor' is how much we guess that the bytes in the source buffer
  1.4766 +     * will expand when converted to UTF-8 chars.  This guess comes from
  1.4767 +     * analyzing how many characters were produced by the previous
  1.4768 +     * pass.
  1.4769 +     */
  1.4770 +
  1.4771 +    dstNeeded = toRead * factor / UTF_EXPANSION_FACTOR;
  1.4772 +    spaceLeft = objPtr->length - offset - TCL_UTF_MAX - 1;
  1.4773 +
  1.4774 +    if (dstNeeded > spaceLeft) {
  1.4775 +	/*
  1.4776 +	 * Double the existing size of the object or make enough room to
  1.4777 +	 * hold all the characters we want from the source buffer,
  1.4778 +	 * whichever is larger.
  1.4779 +	 */
  1.4780 +
  1.4781 +	length = offset * 2;
  1.4782 +	if (offset < dstNeeded) {
  1.4783 +	    length = offset + dstNeeded;
  1.4784 +	}
  1.4785 +	spaceLeft = length - offset;
  1.4786 +	length += TCL_UTF_MAX + 1;
  1.4787 +	Tcl_SetObjLength(objPtr, length);
  1.4788 +    }
  1.4789 +    if (toRead == srcLen) {
  1.4790 +	/*
  1.4791 +	 * Want to convert the whole buffer in one pass.  If we have
  1.4792 +	 * enough space, convert it using all available space in object
  1.4793 +	 * rather than using the factor.
  1.4794 +	 */
  1.4795 +
  1.4796 +	dstNeeded = spaceLeft;
  1.4797 +    }
  1.4798 +    dst = objPtr->bytes + offset;
  1.4799 +
  1.4800 +    /*
  1.4801 +     * SF Tcl Bug 1462248
  1.4802 +     * The cause of the crash reported in the referenced bug is this:
  1.4803 +     *
  1.4804 +     * - ReadChars, called with a single buffer, with a incomplete
  1.4805 +     *   multi-byte character at the end (only the first byte of it).
  1.4806 +     * - Encoding translation fails, asks for more data
  1.4807 +     * - Data is read, and eof is reached, TCL_ENCODING_END (TEE) is set.
  1.4808 +     * - ReadChar is called again, converts the first buffer, but due
  1.4809 +     *   to TEE it does not check for incomplete multi-byte data, and the
  1.4810 +     *   character just after the end of the first buffer is a valid
  1.4811 +     *   completion of the multi-byte header in the actual buffer. The
  1.4812 +     *   conversion reads more characters from the buffer then present.
  1.4813 +     *   This causes nextRemoved to overshoot nextAdded and the next
  1.4814 +     *   reads compute a negative srcLen, cause further translations to
  1.4815 +     *   fail, causing copying of data into the next buffer using bad
  1.4816 +     *   arguments, causing the mecpy for to eventually fail.
  1.4817 +     *
  1.4818 +     * In the end it is a memory access bug spiraling out of control
  1.4819 +     * if the conditions are _just so_. And ultimate cause is that TEE
  1.4820 +     * is given to a conversion where it should not. TEE signals that
  1.4821 +     * this is the last buffer. Except in our case it is not.
  1.4822 +     *
  1.4823 +     * My solution is to suppress TEE if the first buffer is not the
  1.4824 +     * last. We will eventually need it given that EOF has been
  1.4825 +     * reached, but not right now. This is what the new flag
  1.4826 +     * "endEncSuppressFlag" is for.
  1.4827 +     *
  1.4828 +     * The bug in 'Tcl_Utf2UtfProc' where it read from memory behind
  1.4829 +     * the actual buffer has been fixed as well, and fixes the problem
  1.4830 +     * with the crash too, but this would still allow the generic
  1.4831 +     * layer to accidentially break a multi-byte sequence if the
  1.4832 +     * conditions are just right, because again the ExternalToUtf
  1.4833 +     * would be successful where it should not.
  1.4834 +     */
  1.4835 +
  1.4836 +    if ((statePtr->inputEncodingFlags & TCL_ENCODING_END) &&
  1.4837 +	(bufPtr->nextPtr != NULL)) {
  1.4838 +
  1.4839 +        /* TEE is set for a buffer which is not the last. Squash it
  1.4840 +	 * for now, and restore it later, before yielding control to
  1.4841 +	 * our caller.
  1.4842 +	 */
  1.4843 +
  1.4844 +        statePtr->inputEncodingFlags &= ~TCL_ENCODING_END;
  1.4845 +        encEndFlagSuppressed = 1;
  1.4846 +    }
  1.4847 +
  1.4848 +    oldState = statePtr->inputEncodingState;
  1.4849 +    if (statePtr->flags & INPUT_NEED_NL) {
  1.4850 +	/*
  1.4851 +	 * We want a '\n' because the last character we saw was '\r'.
  1.4852 +	 */
  1.4853 +
  1.4854 +	statePtr->flags &= ~INPUT_NEED_NL;
  1.4855 +	Tcl_ExternalToUtf(NULL, statePtr->encoding, src, srcLen,
  1.4856 +		statePtr->inputEncodingFlags, &statePtr->inputEncodingState,
  1.4857 +		dst, TCL_UTF_MAX + 1, &srcRead, &dstWrote, &numChars);
  1.4858 +	if ((dstWrote > 0) && (*dst == '\n')) {
  1.4859 +	    /*
  1.4860 +	     * The next char was a '\n'.  Consume it and produce a '\n'.
  1.4861 +	     */
  1.4862 +
  1.4863 +	    bufPtr->nextRemoved += srcRead;
  1.4864 +	} else {
  1.4865 +	    /*
  1.4866 +	     * The next char was not a '\n'.  Produce a '\r'.
  1.4867 +	     */
  1.4868 +
  1.4869 +	    *dst = '\r';
  1.4870 +	}
  1.4871 +	statePtr->inputEncodingFlags &= ~TCL_ENCODING_START;
  1.4872 +	*offsetPtr += 1;
  1.4873 +
  1.4874 +	if (encEndFlagSuppressed) {
  1.4875 +	    statePtr->inputEncodingFlags |= TCL_ENCODING_END;
  1.4876 +	}
  1.4877 +        return 1;
  1.4878 +    }
  1.4879 +
  1.4880 +    Tcl_ExternalToUtf(NULL, statePtr->encoding, src, srcLen,
  1.4881 +	    statePtr->inputEncodingFlags, &statePtr->inputEncodingState, dst,
  1.4882 +	    dstNeeded + TCL_UTF_MAX, &srcRead, &dstWrote, &numChars);
  1.4883 +
  1.4884 +    if (encEndFlagSuppressed) {
  1.4885 +        statePtr->inputEncodingFlags |= TCL_ENCODING_END;
  1.4886 +    }
  1.4887 +
  1.4888 +    if (srcRead == 0) {
  1.4889 +	/*
  1.4890 +	 * Not enough bytes in src buffer to make a complete char.  Copy
  1.4891 +	 * the bytes to the next buffer to make a new contiguous string,
  1.4892 +	 * then tell the caller to fill the buffer with more bytes.
  1.4893 +	 */
  1.4894 +
  1.4895 +	ChannelBuffer *nextPtr;
  1.4896 +	
  1.4897 +	nextPtr = bufPtr->nextPtr;
  1.4898 +	if (nextPtr == NULL) {
  1.4899 +	    if (srcLen > 0) {
  1.4900 +	        /*
  1.4901 +		 * There isn't enough data in the buffers to complete the next
  1.4902 +		 * character, so we need to wait for more data before the next
  1.4903 +		 * file event can be delivered.
  1.4904 +		 *
  1.4905 +		 * SF #478856.
  1.4906 +		 *
  1.4907 +		 * The exception to this is if the input buffer was
  1.4908 +		 * completely empty before we tried to convert its
  1.4909 +		 * contents. Nothing in, nothing out, and no incomplete
  1.4910 +		 * character data. The conversion before the current one
  1.4911 +		 * was complete.
  1.4912 +		 */
  1.4913 +
  1.4914 +	        statePtr->flags |= CHANNEL_NEED_MORE_DATA;
  1.4915 +	    }
  1.4916 +	    return -1;
  1.4917 +	}
  1.4918 +
  1.4919 +	/* Space is made at the beginning of the buffer to copy the
  1.4920 +	 * previous unused bytes there. Check first if the buffer we
  1.4921 +	 * are using actually has enough space at its beginning for
  1.4922 +	 * the data we are copying. Because if not we will write over the
  1.4923 +	 * buffer management information, especially the 'nextPtr'.
  1.4924 +	 *
  1.4925 +	 * Note that the BUFFER_PADDING (See AllocChannelBuffer) is
  1.4926 +	 * used to prevent exactly this situation. I.e. it should
  1.4927 +	 * never happen. Therefore it is ok to panic should it happen
  1.4928 +	 * despite the precautions.
  1.4929 +	 */
  1.4930 +
  1.4931 +	if (nextPtr->nextRemoved - srcLen < 0) {
  1.4932 +	    Tcl_Panic ("Buffer Underflow, BUFFER_PADDING not enough");
  1.4933 +	}
  1.4934 +
  1.4935 +	nextPtr->nextRemoved -= srcLen;
  1.4936 +	memcpy((VOID *) (nextPtr->buf + nextPtr->nextRemoved), (VOID *) src,
  1.4937 +		(size_t) srcLen);
  1.4938 +	RecycleBuffer(statePtr, bufPtr, 0);
  1.4939 +	statePtr->inQueueHead = nextPtr;
  1.4940 +	return ReadChars(statePtr, objPtr, charsToRead, offsetPtr, factorPtr);
  1.4941 +    }
  1.4942 +
  1.4943 +    dstRead = dstWrote;
  1.4944 +    if (TranslateInputEOL(statePtr, dst, dst, &dstWrote, &dstRead) != 0) {
  1.4945 +	/*
  1.4946 +	 * Hit EOF char.  How many bytes of src correspond to where the
  1.4947 +	 * EOF was located in dst? Run the conversion again with an
  1.4948 +	 * output buffer just big enough to hold the data so we can
  1.4949 +	 * get the correct value for srcRead.
  1.4950 +	 */
  1.4951 +	 
  1.4952 +	if (dstWrote == 0) {
  1.4953 +	    return -1;
  1.4954 +	}
  1.4955 +	statePtr->inputEncodingState = oldState;
  1.4956 +	Tcl_ExternalToUtf(NULL, statePtr->encoding, src, srcLen,
  1.4957 +		statePtr->inputEncodingFlags, &statePtr->inputEncodingState,
  1.4958 +		dst, dstRead + TCL_UTF_MAX, &srcRead, &dstWrote, &numChars);
  1.4959 +	TranslateInputEOL(statePtr, dst, dst, &dstWrote, &dstRead);
  1.4960 +    } 
  1.4961 +
  1.4962 +    /*
  1.4963 +     * The number of characters that we got may be less than the number
  1.4964 +     * that we started with because "\r\n" sequences may have been
  1.4965 +     * turned into just '\n' in dst.
  1.4966 +     */
  1.4967 +
  1.4968 +    numChars -= (dstRead - dstWrote);
  1.4969 +
  1.4970 +    if ((unsigned) numChars > (unsigned) toRead) {
  1.4971 +	/*
  1.4972 +	 * Got too many chars.
  1.4973 +	 */
  1.4974 +
  1.4975 +	CONST char *eof;
  1.4976 +
  1.4977 +	eof = Tcl_UtfAtIndex(dst, toRead);
  1.4978 +	statePtr->inputEncodingState = oldState;
  1.4979 +	Tcl_ExternalToUtf(NULL, statePtr->encoding, src, srcLen,
  1.4980 +		statePtr->inputEncodingFlags, &statePtr->inputEncodingState,
  1.4981 +		dst, eof - dst + TCL_UTF_MAX, &srcRead, &dstWrote, &numChars);
  1.4982 +	dstRead = dstWrote;
  1.4983 +	TranslateInputEOL(statePtr, dst, dst, &dstWrote, &dstRead);
  1.4984 +	numChars -= (dstRead - dstWrote);
  1.4985 +    }
  1.4986 +    statePtr->inputEncodingFlags &= ~TCL_ENCODING_START;
  1.4987 +
  1.4988 +    bufPtr->nextRemoved += srcRead;
  1.4989 +    if (dstWrote > srcRead + 1) {
  1.4990 +	*factorPtr = dstWrote * UTF_EXPANSION_FACTOR / srcRead;
  1.4991 +    }
  1.4992 +    *offsetPtr += dstWrote;
  1.4993 +    return numChars;
  1.4994 +}
  1.4995 +
  1.4996 +/*
  1.4997 + *---------------------------------------------------------------------------
  1.4998 + *
  1.4999 + * TranslateInputEOL --
  1.5000 + *
  1.5001 + *	Perform input EOL and EOF translation on the source buffer,
  1.5002 + *	leaving the translated result in the destination buffer.  
  1.5003 + *
  1.5004 + * Results:
  1.5005 + *	The return value is 1 if the EOF character was found when copying
  1.5006 + *	bytes to the destination buffer, 0 otherwise.  
  1.5007 + *
  1.5008 + * Side effects:
  1.5009 + *	None.
  1.5010 + *
  1.5011 + *---------------------------------------------------------------------------
  1.5012 + */
  1.5013 +
  1.5014 +static int
  1.5015 +TranslateInputEOL(statePtr, dstStart, srcStart, dstLenPtr, srcLenPtr)
  1.5016 +    ChannelState *statePtr;	/* Channel being read, for EOL translation
  1.5017 +				 * and EOF character. */
  1.5018 +    char *dstStart;		/* Output buffer filled with chars by
  1.5019 +				 * applying appropriate EOL translation to
  1.5020 +				 * source characters. */
  1.5021 +    CONST char *srcStart;	/* Source characters. */
  1.5022 +    int *dstLenPtr;		/* On entry, the maximum length of output
  1.5023 +				 * buffer in bytes; must be <= *srcLenPtr.  On
  1.5024 +				 * exit, the number of bytes actually used in
  1.5025 +				 * output buffer. */
  1.5026 +    int *srcLenPtr;		/* On entry, the length of source buffer.
  1.5027 +				 * On exit, the number of bytes read from
  1.5028 +				 * the source buffer. */
  1.5029 +{
  1.5030 +    int dstLen, srcLen, inEofChar;
  1.5031 +    CONST char *eof;
  1.5032 +
  1.5033 +    dstLen = *dstLenPtr;
  1.5034 +
  1.5035 +    eof = NULL;
  1.5036 +    inEofChar = statePtr->inEofChar;
  1.5037 +    if (inEofChar != '\0') {
  1.5038 +	/*
  1.5039 +	 * Find EOF in translated buffer then compress out the EOL.  The
  1.5040 +	 * source buffer may be much longer than the destination buffer --
  1.5041 +	 * we only want to return EOF if the EOF has been copied to the
  1.5042 +	 * destination buffer.
  1.5043 +	 */
  1.5044 +
  1.5045 +	CONST char *src, *srcMax;
  1.5046 +
  1.5047 +	srcMax = srcStart + *srcLenPtr;
  1.5048 +	for (src = srcStart; src < srcMax; src++) {
  1.5049 +	    if (*src == inEofChar) {
  1.5050 +		eof = src;
  1.5051 +		srcLen = src - srcStart;
  1.5052 +		if (srcLen < dstLen) {
  1.5053 +		    dstLen = srcLen;
  1.5054 +		}
  1.5055 +		*srcLenPtr = srcLen;
  1.5056 +		break;
  1.5057 +	    }
  1.5058 +	}
  1.5059 +    }
  1.5060 +    switch (statePtr->inputTranslation) {
  1.5061 +	case TCL_TRANSLATE_LF: {
  1.5062 +	    if (dstStart != srcStart) {
  1.5063 +		memcpy((VOID *) dstStart, (VOID *) srcStart, (size_t) dstLen);
  1.5064 +	    }
  1.5065 +	    srcLen = dstLen;
  1.5066 +	    break;
  1.5067 +	}
  1.5068 +	case TCL_TRANSLATE_CR: {
  1.5069 +	    char *dst, *dstEnd;
  1.5070 +	    
  1.5071 +	    if (dstStart != srcStart) {
  1.5072 +		memcpy((VOID *) dstStart, (VOID *) srcStart, (size_t) dstLen);
  1.5073 +	    }
  1.5074 +	    dstEnd = dstStart + dstLen;
  1.5075 +	    for (dst = dstStart; dst < dstEnd; dst++) {
  1.5076 +		if (*dst == '\r') {
  1.5077 +		    *dst = '\n';
  1.5078 +		}
  1.5079 +	    }
  1.5080 +	    srcLen = dstLen;
  1.5081 +	    break;
  1.5082 +	}
  1.5083 +	case TCL_TRANSLATE_CRLF: {
  1.5084 +	    char *dst;
  1.5085 +	    CONST char *src, *srcEnd, *srcMax;
  1.5086 +	    
  1.5087 +	    dst = dstStart;
  1.5088 +	    src = srcStart;
  1.5089 +	    srcEnd = srcStart + dstLen;
  1.5090 +	    srcMax = srcStart + *srcLenPtr;
  1.5091 +
  1.5092 +	    for ( ; src < srcEnd; ) {
  1.5093 +		if (*src == '\r') {
  1.5094 +		    src++;
  1.5095 +		    if (src >= srcMax) {
  1.5096 +			statePtr->flags |= INPUT_NEED_NL;
  1.5097 +		    } else if (*src == '\n') {
  1.5098 +			*dst++ = *src++;
  1.5099 +		    } else {
  1.5100 +			*dst++ = '\r';
  1.5101 +		    }
  1.5102 +		} else {
  1.5103 +		    *dst++ = *src++;
  1.5104 +		}
  1.5105 +	    }
  1.5106 +	    srcLen = src - srcStart;
  1.5107 +	    dstLen = dst - dstStart;
  1.5108 +	    break;
  1.5109 +	}
  1.5110 +	case TCL_TRANSLATE_AUTO: {
  1.5111 +	    char *dst;
  1.5112 +	    CONST char *src, *srcEnd, *srcMax;
  1.5113 +
  1.5114 +	    dst = dstStart;
  1.5115 +	    src = srcStart;
  1.5116 +	    srcEnd = srcStart + dstLen;
  1.5117 +	    srcMax = srcStart + *srcLenPtr;
  1.5118 +
  1.5119 +	    if ((statePtr->flags & INPUT_SAW_CR) && (src < srcMax)) {
  1.5120 +		if (*src == '\n') {
  1.5121 +		    src++;
  1.5122 +		}
  1.5123 +		statePtr->flags &= ~INPUT_SAW_CR;
  1.5124 +	    }
  1.5125 +	    for ( ; src < srcEnd; ) {
  1.5126 +		if (*src == '\r') {
  1.5127 +		    src++;
  1.5128 +		    if (src >= srcMax) {
  1.5129 +			statePtr->flags |= INPUT_SAW_CR;
  1.5130 +		    } else if (*src == '\n') {
  1.5131 +			if (srcEnd < srcMax) {
  1.5132 +			    srcEnd++;
  1.5133 +			}
  1.5134 +			src++;
  1.5135 +		    }
  1.5136 +		    *dst++ = '\n';
  1.5137 +		} else {
  1.5138 +		    *dst++ = *src++;
  1.5139 +		}
  1.5140 +	    }
  1.5141 +	    srcLen = src - srcStart;
  1.5142 +	    dstLen = dst - dstStart;
  1.5143 +	    break;
  1.5144 +	}
  1.5145 +	default: {		/* lint. */
  1.5146 +	    return 0;
  1.5147 +	}
  1.5148 +    }
  1.5149 +    *dstLenPtr = dstLen;
  1.5150 +
  1.5151 +    if ((eof != NULL) && (srcStart + srcLen >= eof)) {
  1.5152 +	/*
  1.5153 +	 * EOF character was seen in EOL translated range.  Leave current
  1.5154 +	 * file position pointing at the EOF character, but don't store the
  1.5155 +	 * EOF character in the output string.
  1.5156 +	 */
  1.5157 +
  1.5158 +	statePtr->flags |= (CHANNEL_EOF | CHANNEL_STICKY_EOF);
  1.5159 +	statePtr->inputEncodingFlags |= TCL_ENCODING_END;
  1.5160 +	statePtr->flags &= ~(INPUT_SAW_CR | INPUT_NEED_NL);
  1.5161 +	return 1;
  1.5162 +    }
  1.5163 +
  1.5164 +    *srcLenPtr = srcLen;
  1.5165 +    return 0;
  1.5166 +}
  1.5167 +
  1.5168 +/*
  1.5169 + *----------------------------------------------------------------------
  1.5170 + *
  1.5171 + * Tcl_Ungets --
  1.5172 + *
  1.5173 + *	Causes the supplied string to be added to the input queue of
  1.5174 + *	the channel, at either the head or tail of the queue.
  1.5175 + *
  1.5176 + * Results:
  1.5177 + *	The number of bytes stored in the channel, or -1 on error.
  1.5178 + *
  1.5179 + * Side effects:
  1.5180 + *	Adds input to the input queue of a channel.
  1.5181 + *
  1.5182 + *----------------------------------------------------------------------
  1.5183 + */
  1.5184 +
  1.5185 +EXPORT_C int
  1.5186 +Tcl_Ungets(chan, str, len, atEnd)
  1.5187 +    Tcl_Channel chan;		/* The channel for which to add the input. */
  1.5188 +    CONST char *str;		/* The input itself. */
  1.5189 +    int len;			/* The length of the input. */
  1.5190 +    int atEnd;			/* If non-zero, add at end of queue; otherwise
  1.5191 +                                 * add at head of queue. */    
  1.5192 +{
  1.5193 +    Channel *chanPtr;		/* The real IO channel. */
  1.5194 +    ChannelState *statePtr;	/* State of actual channel. */
  1.5195 +    ChannelBuffer *bufPtr;	/* Buffer to contain the data. */
  1.5196 +    int i, flags;
  1.5197 +
  1.5198 +    chanPtr = (Channel *) chan;
  1.5199 +    statePtr = chanPtr->state;
  1.5200 +
  1.5201 +    /*
  1.5202 +     * This operation should occur at the top of a channel stack.
  1.5203 +     */
  1.5204 +
  1.5205 +    chanPtr = statePtr->topChanPtr;
  1.5206 +
  1.5207 +    /*
  1.5208 +     * CheckChannelErrors clears too many flag bits in this one case.
  1.5209 +     */
  1.5210 +     
  1.5211 +    flags = statePtr->flags;
  1.5212 +    if (CheckChannelErrors(statePtr, TCL_READABLE) != 0) {
  1.5213 +	len = -1;
  1.5214 +	goto done;
  1.5215 +    }
  1.5216 +    statePtr->flags = flags;
  1.5217 +
  1.5218 +    /*
  1.5219 +     * If we have encountered a sticky EOF, just punt without storing.
  1.5220 +     * (sticky EOF is set if we have seen the input eofChar, to prevent
  1.5221 +     * reading beyond the eofChar). Otherwise, clear the EOF flags, and
  1.5222 +     * clear the BLOCKED bit. We want to discover these conditions anew
  1.5223 +     * in each operation.
  1.5224 +     */
  1.5225 +
  1.5226 +    if (statePtr->flags & CHANNEL_STICKY_EOF) {
  1.5227 +	goto done;
  1.5228 +    }
  1.5229 +    statePtr->flags &= (~(CHANNEL_BLOCKED | CHANNEL_EOF));
  1.5230 +
  1.5231 +    bufPtr = AllocChannelBuffer(len);
  1.5232 +    for (i = 0; i < len; i++) {
  1.5233 +        bufPtr->buf[bufPtr->nextAdded++] = str[i];
  1.5234 +    }
  1.5235 +
  1.5236 +    if (statePtr->inQueueHead == (ChannelBuffer *) NULL) {
  1.5237 +        bufPtr->nextPtr = (ChannelBuffer *) NULL;
  1.5238 +        statePtr->inQueueHead = bufPtr;
  1.5239 +        statePtr->inQueueTail = bufPtr;
  1.5240 +    } else if (atEnd) {
  1.5241 +        bufPtr->nextPtr = (ChannelBuffer *) NULL;
  1.5242 +        statePtr->inQueueTail->nextPtr = bufPtr;
  1.5243 +        statePtr->inQueueTail = bufPtr;
  1.5244 +    } else {
  1.5245 +        bufPtr->nextPtr = statePtr->inQueueHead;
  1.5246 +        statePtr->inQueueHead = bufPtr;
  1.5247 +    }
  1.5248 +
  1.5249 +    done:
  1.5250 +    /*
  1.5251 +     * Update the notifier state so we don't block while there is still
  1.5252 +     * data in the buffers.
  1.5253 +     */
  1.5254 +
  1.5255 +    UpdateInterest(chanPtr);
  1.5256 +    return len;
  1.5257 +}
  1.5258 +
  1.5259 +/*
  1.5260 + *----------------------------------------------------------------------
  1.5261 + *
  1.5262 + * Tcl_Flush --
  1.5263 + *
  1.5264 + *	Flushes output data on a channel.
  1.5265 + *
  1.5266 + * Results:
  1.5267 + *	A standard Tcl result.
  1.5268 + *
  1.5269 + * Side effects:
  1.5270 + *	May flush output queued on this channel.
  1.5271 + *
  1.5272 + *----------------------------------------------------------------------
  1.5273 + */
  1.5274 +
  1.5275 +EXPORT_C int
  1.5276 +Tcl_Flush(chan)
  1.5277 +    Tcl_Channel chan;			/* The Channel to flush. */
  1.5278 +{
  1.5279 +    int result;				/* Of calling FlushChannel. */
  1.5280 +    Channel *chanPtr  = (Channel *) chan;	/* The actual channel. */
  1.5281 +    ChannelState *statePtr = chanPtr->state;	/* State of actual channel. */
  1.5282 +
  1.5283 +    /*
  1.5284 +     * This operation should occur at the top of a channel stack.
  1.5285 +     */
  1.5286 +
  1.5287 +    chanPtr = statePtr->topChanPtr;
  1.5288 +
  1.5289 +    if (CheckChannelErrors(statePtr, TCL_WRITABLE) != 0) {
  1.5290 +	return -1;
  1.5291 +    }
  1.5292 +
  1.5293 +    /*
  1.5294 +     * Force current output buffer to be output also.
  1.5295 +     */
  1.5296 +
  1.5297 +    if ((statePtr->curOutPtr != NULL)
  1.5298 +	    && (statePtr->curOutPtr->nextAdded > 0)) {
  1.5299 +        statePtr->flags |= BUFFER_READY;
  1.5300 +    }
  1.5301 +    
  1.5302 +    result = FlushChannel(NULL, chanPtr, 0);
  1.5303 +    if (result != 0) {
  1.5304 +        return TCL_ERROR;
  1.5305 +    }
  1.5306 +
  1.5307 +    return TCL_OK;
  1.5308 +}
  1.5309 +
  1.5310 +/*
  1.5311 + *----------------------------------------------------------------------
  1.5312 + *
  1.5313 + * DiscardInputQueued --
  1.5314 + *
  1.5315 + *	Discards any input read from the channel but not yet consumed
  1.5316 + *	by Tcl reading commands.
  1.5317 + *
  1.5318 + * Results:
  1.5319 + *	None.
  1.5320 + *
  1.5321 + * Side effects:
  1.5322 + *	May discard input from the channel. If discardLastBuffer is zero,
  1.5323 + *	leaves one buffer in place for back-filling.
  1.5324 + *
  1.5325 + *----------------------------------------------------------------------
  1.5326 + */
  1.5327 +
  1.5328 +static void
  1.5329 +DiscardInputQueued(statePtr, discardSavedBuffers)
  1.5330 +    ChannelState *statePtr;	/* Channel on which to discard
  1.5331 +                                 * the queued input. */
  1.5332 +    int discardSavedBuffers;	/* If non-zero, discard all buffers including
  1.5333 +                                 * last one. */
  1.5334 +{
  1.5335 +    ChannelBuffer *bufPtr, *nxtPtr;	/* Loop variables. */
  1.5336 +
  1.5337 +    bufPtr = statePtr->inQueueHead;
  1.5338 +    statePtr->inQueueHead = (ChannelBuffer *) NULL;
  1.5339 +    statePtr->inQueueTail = (ChannelBuffer *) NULL;
  1.5340 +    for (; bufPtr != (ChannelBuffer *) NULL; bufPtr = nxtPtr) {
  1.5341 +        nxtPtr = bufPtr->nextPtr;
  1.5342 +        RecycleBuffer(statePtr, bufPtr, discardSavedBuffers);
  1.5343 +    }
  1.5344 +
  1.5345 +    /*
  1.5346 +     * If discardSavedBuffers is nonzero, must also discard any previously
  1.5347 +     * saved buffer in the saveInBufPtr field.
  1.5348 +     */
  1.5349 +    
  1.5350 +    if (discardSavedBuffers) {
  1.5351 +        if (statePtr->saveInBufPtr != (ChannelBuffer *) NULL) {
  1.5352 +            ckfree((char *) statePtr->saveInBufPtr);
  1.5353 +            statePtr->saveInBufPtr = (ChannelBuffer *) NULL;
  1.5354 +        }
  1.5355 +    }
  1.5356 +}
  1.5357 +
  1.5358 +/*
  1.5359 + *---------------------------------------------------------------------------
  1.5360 + *
  1.5361 + * GetInput --
  1.5362 + *
  1.5363 + *	Reads input data from a device into a channel buffer.  
  1.5364 + *
  1.5365 + * Results:
  1.5366 + *	The return value is the Posix error code if an error occurred while
  1.5367 + *	reading from the file, or 0 otherwise.  
  1.5368 + *
  1.5369 + * Side effects:
  1.5370 + *	Reads from the underlying device.
  1.5371 + *
  1.5372 + *---------------------------------------------------------------------------
  1.5373 + */
  1.5374 +
  1.5375 +static int
  1.5376 +GetInput(chanPtr)
  1.5377 +    Channel *chanPtr;		/* Channel to read input from. */
  1.5378 +{
  1.5379 +    int toRead;			/* How much to read? */
  1.5380 +    int result;			/* Of calling driver. */
  1.5381 +    int nread;			/* How much was read from channel? */
  1.5382 +    ChannelBuffer *bufPtr;	/* New buffer to add to input queue. */
  1.5383 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.5384 +
  1.5385 +    /*
  1.5386 +     * Prevent reading from a dead channel -- a channel that has been closed
  1.5387 +     * but not yet deallocated, which can happen if the exit handler for
  1.5388 +     * channel cleanup has run but the channel is still registered in some
  1.5389 +     * interpreter.
  1.5390 +     */
  1.5391 +    
  1.5392 +    if (CheckForDeadChannel(NULL, statePtr)) {
  1.5393 +	return EINVAL;
  1.5394 +    }
  1.5395 +
  1.5396 +    /*
  1.5397 +     * First check for more buffers in the pushback area of the
  1.5398 +     * topmost channel in the stack and use them. They can be the
  1.5399 +     * result of a transformation which went away without reading all
  1.5400 +     * the information placed in the area when it was stacked.
  1.5401 +     *
  1.5402 +     * Two possibilities for the state: No buffers in it, or a single
  1.5403 +     * empty buffer. In the latter case we can recycle it now.
  1.5404 +     */
  1.5405 +
  1.5406 +    if (chanPtr->inQueueHead != (ChannelBuffer*) NULL) {
  1.5407 +        if (statePtr->inQueueHead != (ChannelBuffer*) NULL) {
  1.5408 +	    RecycleBuffer(statePtr, statePtr->inQueueHead, 0);
  1.5409 +	    statePtr->inQueueHead = (ChannelBuffer*) NULL;
  1.5410 +	}
  1.5411 +
  1.5412 +	statePtr->inQueueHead = chanPtr->inQueueHead;
  1.5413 +	statePtr->inQueueTail = chanPtr->inQueueTail;
  1.5414 +	chanPtr->inQueueHead  = (ChannelBuffer*) NULL;
  1.5415 +	chanPtr->inQueueTail  = (ChannelBuffer*) NULL;
  1.5416 +	return 0;
  1.5417 +    }
  1.5418 +
  1.5419 +    /*
  1.5420 +     * Nothing in the pushback area, fall back to the usual handling
  1.5421 +     * (driver, etc.)
  1.5422 +     */
  1.5423 +
  1.5424 +    /*
  1.5425 +     * See if we can fill an existing buffer. If we can, read only
  1.5426 +     * as much as will fit in it. Otherwise allocate a new buffer,
  1.5427 +     * add it to the input queue and attempt to fill it to the max.
  1.5428 +     */
  1.5429 +
  1.5430 +    bufPtr = statePtr->inQueueTail;
  1.5431 +    if ((bufPtr != NULL) && (bufPtr->nextAdded < bufPtr->bufLength)) {
  1.5432 +        toRead = bufPtr->bufLength - bufPtr->nextAdded;
  1.5433 +    } else {
  1.5434 +	bufPtr = statePtr->saveInBufPtr;
  1.5435 +	statePtr->saveInBufPtr = NULL;
  1.5436 +
  1.5437 +	/*
  1.5438 +	 * Check the actual buffersize against the requested
  1.5439 +	 * buffersize. Buffers which are smaller than requested are
  1.5440 +	 * squashed. This is done to honor dynamic changes of the
  1.5441 +	 * buffersize made by the user.
  1.5442 +	 */
  1.5443 +
  1.5444 +	if ((bufPtr != NULL) && ((bufPtr->bufLength - BUFFER_PADDING) < statePtr->bufSize)) {
  1.5445 +	  ckfree((char *) bufPtr);
  1.5446 +	  bufPtr = NULL;
  1.5447 +	}
  1.5448 +
  1.5449 +	if (bufPtr == NULL) {
  1.5450 +	    bufPtr = AllocChannelBuffer(statePtr->bufSize);
  1.5451 +	}
  1.5452 +        bufPtr->nextPtr = (ChannelBuffer *) NULL;
  1.5453 +
  1.5454 +	/* SF #427196: Use the actual size of the buffer to determine
  1.5455 +	 * the number of bytes to read from the channel and not the
  1.5456 +	 * size for new buffers. They can be different if the
  1.5457 +	 * buffersize was changed between reads.
  1.5458 +	 *
  1.5459 +	 * Note: This affects performance negatively if the buffersize
  1.5460 +	 * was extended but this small buffer is reused for all
  1.5461 +	 * subsequent reads. The system never uses buffers with the
  1.5462 +	 * requested bigger size in that case. An adjunct patch could
  1.5463 +	 * try and delete all unused buffers it encounters and which
  1.5464 +	 * are smaller than the formally requested buffersize.
  1.5465 +	 */
  1.5466 +
  1.5467 +	toRead = bufPtr->bufLength - bufPtr->nextAdded;
  1.5468 +
  1.5469 +        if (statePtr->inQueueTail == NULL) {
  1.5470 +            statePtr->inQueueHead = bufPtr;
  1.5471 +        } else {
  1.5472 +            statePtr->inQueueTail->nextPtr = bufPtr;
  1.5473 +        }
  1.5474 +        statePtr->inQueueTail = bufPtr;
  1.5475 +    }
  1.5476 +
  1.5477 +    /*
  1.5478 +     * If EOF is set, we should avoid calling the driver because on some
  1.5479 +     * platforms it is impossible to read from a device after EOF.
  1.5480 +     */
  1.5481 +
  1.5482 +    if (statePtr->flags & CHANNEL_EOF) {
  1.5483 +	return 0;
  1.5484 +    }
  1.5485 +
  1.5486 +#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
  1.5487 +    /* [SF Tcl Bug 943274]. Better emulation of non-blocking channels
  1.5488 +     * for channels without BlockModeProc, by keeping track of true
  1.5489 +     * fileevents generated by the OS == Data waiting and reading if
  1.5490 +     * and only if we are sure to have data.
  1.5491 +     */
  1.5492 +
  1.5493 +    if ((statePtr->flags & CHANNEL_NONBLOCKING) &&
  1.5494 +	(Tcl_ChannelBlockModeProc(chanPtr->typePtr) == NULL) &&
  1.5495 +	!(statePtr->flags & CHANNEL_HAS_MORE_DATA)) {
  1.5496 +
  1.5497 +        /* Bypass the driver, it would block, as no data is available */
  1.5498 +        nread = -1;
  1.5499 +        result = EWOULDBLOCK;
  1.5500 +    } else {
  1.5501 +#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
  1.5502 +
  1.5503 +        nread = (chanPtr->typePtr->inputProc)(chanPtr->instanceData,
  1.5504 +		    bufPtr->buf + bufPtr->nextAdded, toRead, &result);
  1.5505 +
  1.5506 +#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
  1.5507 +    }
  1.5508 +#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
  1.5509 +
  1.5510 +    if (nread > 0) {
  1.5511 +	bufPtr->nextAdded += nread;
  1.5512 +
  1.5513 +	/*
  1.5514 +	 * If we get a short read, signal up that we may be BLOCKED. We
  1.5515 +	 * should avoid calling the driver because on some platforms we
  1.5516 +	 * will block in the low level reading code even though the
  1.5517 +	 * channel is set into nonblocking mode.
  1.5518 +	 */
  1.5519 +            
  1.5520 +	if (nread < toRead) {
  1.5521 +	    statePtr->flags |= CHANNEL_BLOCKED;
  1.5522 +	}
  1.5523 +
  1.5524 +#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
  1.5525 +	if (nread <= toRead) {
  1.5526 +	  /* [SF Tcl Bug 943274] We have read the available data,
  1.5527 +	   * clear flag */
  1.5528 +	  statePtr->flags &= ~CHANNEL_HAS_MORE_DATA;
  1.5529 +	}
  1.5530 +#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
  1.5531 +
  1.5532 +    } else if (nread == 0) {
  1.5533 +	statePtr->flags |= CHANNEL_EOF;
  1.5534 +	statePtr->inputEncodingFlags |= TCL_ENCODING_END;
  1.5535 +    } else if (nread < 0) {
  1.5536 +	if ((result == EWOULDBLOCK) || (result == EAGAIN)) {
  1.5537 +	    statePtr->flags |= CHANNEL_BLOCKED;
  1.5538 +	    result = EAGAIN;
  1.5539 +	}
  1.5540 +	Tcl_SetErrno(result);
  1.5541 +	return result;
  1.5542 +    }
  1.5543 +    return 0;
  1.5544 +}
  1.5545 +
  1.5546 +/*
  1.5547 + *----------------------------------------------------------------------
  1.5548 + *
  1.5549 + * Tcl_Seek --
  1.5550 + *
  1.5551 + *	Implements seeking on Tcl Channels. This is a public function
  1.5552 + *	so that other C facilities may be implemented on top of it.
  1.5553 + *
  1.5554 + * Results:
  1.5555 + *	The new access point or -1 on error. If error, use Tcl_GetErrno()
  1.5556 + *	to retrieve the POSIX error code for the error that occurred.
  1.5557 + *
  1.5558 + * Side effects:
  1.5559 + *	May flush output on the channel. May discard queued input.
  1.5560 + *
  1.5561 + *----------------------------------------------------------------------
  1.5562 + */
  1.5563 +
  1.5564 +EXPORT_C Tcl_WideInt
  1.5565 +Tcl_Seek(chan, offset, mode)
  1.5566 +    Tcl_Channel chan;		/* The channel on which to seek. */
  1.5567 +    Tcl_WideInt offset;		/* Offset to seek to. */
  1.5568 +    int mode;			/* Relative to which location to seek? */
  1.5569 +{
  1.5570 +    Channel *chanPtr = (Channel *) chan;	/* The real IO channel. */
  1.5571 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.5572 +    int inputBuffered, outputBuffered;
  1.5573 +				/* # bytes held in buffers. */
  1.5574 +    int result;			/* Of device driver operations. */
  1.5575 +    Tcl_WideInt curPos;		/* Position on the device. */
  1.5576 +    int wasAsync;		/* Was the channel nonblocking before the
  1.5577 +                                 * seek operation? If so, must restore to
  1.5578 +                                 * nonblocking mode after the seek. */
  1.5579 +
  1.5580 +    if (CheckChannelErrors(statePtr, TCL_WRITABLE | TCL_READABLE) != 0) {
  1.5581 +	return Tcl_LongAsWide(-1);
  1.5582 +    }
  1.5583 +
  1.5584 +    /*
  1.5585 +     * Disallow seek on dead channels -- channels that have been closed but
  1.5586 +     * not yet been deallocated. Such channels can be found if the exit
  1.5587 +     * handler for channel cleanup has run but the channel is still
  1.5588 +     * registered in an interpreter.
  1.5589 +     */
  1.5590 +
  1.5591 +    if (CheckForDeadChannel(NULL, statePtr)) {
  1.5592 +	return Tcl_LongAsWide(-1);
  1.5593 +    }
  1.5594 +
  1.5595 +    /*
  1.5596 +     * This operation should occur at the top of a channel stack.
  1.5597 +     */
  1.5598 +
  1.5599 +    chanPtr = statePtr->topChanPtr;
  1.5600 +
  1.5601 +    /*
  1.5602 +     * Disallow seek on channels whose type does not have a seek procedure
  1.5603 +     * defined. This means that the channel does not support seeking.
  1.5604 +     */
  1.5605 +
  1.5606 +    if (chanPtr->typePtr->seekProc == (Tcl_DriverSeekProc *) NULL) {
  1.5607 +        Tcl_SetErrno(EINVAL);
  1.5608 +        return Tcl_LongAsWide(-1);
  1.5609 +    }
  1.5610 +
  1.5611 +    /*
  1.5612 +     * Compute how much input and output is buffered. If both input and
  1.5613 +     * output is buffered, cannot compute the current position.
  1.5614 +     */
  1.5615 +
  1.5616 +    inputBuffered = Tcl_InputBuffered(chan);
  1.5617 +    outputBuffered = Tcl_OutputBuffered(chan);
  1.5618 +
  1.5619 +    if ((inputBuffered != 0) && (outputBuffered != 0)) {
  1.5620 +        Tcl_SetErrno(EFAULT);
  1.5621 +        return Tcl_LongAsWide(-1);
  1.5622 +    }
  1.5623 +
  1.5624 +    /*
  1.5625 +     * If we are seeking relative to the current position, compute the
  1.5626 +     * corrected offset taking into account the amount of unread input.
  1.5627 +     */
  1.5628 +
  1.5629 +    if (mode == SEEK_CUR) {
  1.5630 +        offset -= inputBuffered;
  1.5631 +    }
  1.5632 +
  1.5633 +    /*
  1.5634 +     * Discard any queued input - this input should not be read after
  1.5635 +     * the seek.
  1.5636 +     */
  1.5637 +
  1.5638 +    DiscardInputQueued(statePtr, 0);
  1.5639 +
  1.5640 +    /*
  1.5641 +     * Reset EOF and BLOCKED flags. We invalidate them by moving the
  1.5642 +     * access point. Also clear CR related flags.
  1.5643 +     */
  1.5644 +
  1.5645 +    statePtr->flags &=
  1.5646 +        (~(CHANNEL_EOF | CHANNEL_STICKY_EOF | CHANNEL_BLOCKED | INPUT_SAW_CR));
  1.5647 +    
  1.5648 +    /*
  1.5649 +     * If the channel is in asynchronous output mode, switch it back
  1.5650 +     * to synchronous mode and cancel any async flush that may be
  1.5651 +     * scheduled. After the flush, the channel will be put back into
  1.5652 +     * asynchronous output mode.
  1.5653 +     */
  1.5654 +
  1.5655 +    wasAsync = 0;
  1.5656 +    if (statePtr->flags & CHANNEL_NONBLOCKING) {
  1.5657 +        wasAsync = 1;
  1.5658 +        result = StackSetBlockMode(chanPtr, TCL_MODE_BLOCKING);
  1.5659 +	if (result != 0) {
  1.5660 +	    return Tcl_LongAsWide(-1);
  1.5661 +	}
  1.5662 +        statePtr->flags &= (~(CHANNEL_NONBLOCKING));
  1.5663 +        if (statePtr->flags & BG_FLUSH_SCHEDULED) {
  1.5664 +            statePtr->flags &= (~(BG_FLUSH_SCHEDULED));
  1.5665 +        }
  1.5666 +    }
  1.5667 +    
  1.5668 +    /*
  1.5669 +     * If the flush fails we cannot recover the original position. In
  1.5670 +     * that case the seek is not attempted because we do not know where
  1.5671 +     * the access position is - instead we return the error. FlushChannel
  1.5672 +     * has already called Tcl_SetErrno() to report the error upwards.
  1.5673 +     * If the flush succeeds we do the seek also.
  1.5674 +     */
  1.5675 +    
  1.5676 +    if (FlushChannel(NULL, chanPtr, 0) != 0) {
  1.5677 +        curPos = -1;
  1.5678 +    } else {
  1.5679 +
  1.5680 +        /*
  1.5681 +         * Now seek to the new position in the channel as requested by the
  1.5682 +         * caller.  Note that we prefer the wideSeekProc if that is
  1.5683 +	 * available and non-NULL...
  1.5684 +         */
  1.5685 +
  1.5686 +	if (HaveVersion(chanPtr->typePtr, TCL_CHANNEL_VERSION_3) &&
  1.5687 +		chanPtr->typePtr->wideSeekProc != NULL) {
  1.5688 +	    curPos = (chanPtr->typePtr->wideSeekProc) (chanPtr->instanceData,
  1.5689 +		    offset, mode, &result);
  1.5690 +	} else if (offset < Tcl_LongAsWide(LONG_MIN) ||
  1.5691 +		offset > Tcl_LongAsWide(LONG_MAX)) {
  1.5692 +	    result = EOVERFLOW;
  1.5693 +	    curPos = Tcl_LongAsWide(-1);
  1.5694 +	} else {
  1.5695 +	    curPos = Tcl_LongAsWide((chanPtr->typePtr->seekProc) (
  1.5696 +		    chanPtr->instanceData, Tcl_WideAsLong(offset), mode,
  1.5697 +		    &result));
  1.5698 +	}
  1.5699 +	if (curPos == Tcl_LongAsWide(-1)) {
  1.5700 +	    Tcl_SetErrno(result);
  1.5701 +	}
  1.5702 +    }
  1.5703 +    
  1.5704 +    /*
  1.5705 +     * Restore to nonblocking mode if that was the previous behavior.
  1.5706 +     *
  1.5707 +     * NOTE: Even if there was an async flush active we do not restore
  1.5708 +     * it now because we already flushed all the queued output, above.
  1.5709 +     */
  1.5710 +    
  1.5711 +    if (wasAsync) {
  1.5712 +        statePtr->flags |= CHANNEL_NONBLOCKING;
  1.5713 +        result = StackSetBlockMode(chanPtr, TCL_MODE_NONBLOCKING);
  1.5714 +	if (result != 0) {
  1.5715 +	    return Tcl_LongAsWide(-1);
  1.5716 +	}
  1.5717 +    }
  1.5718 +
  1.5719 +    return curPos;
  1.5720 +}
  1.5721 +
  1.5722 +/*
  1.5723 + *----------------------------------------------------------------------
  1.5724 + *
  1.5725 + * Tcl_Tell --
  1.5726 + *
  1.5727 + *	Returns the position of the next character to be read/written on
  1.5728 + *	this channel.
  1.5729 + *
  1.5730 + * Results:
  1.5731 + *	A nonnegative integer on success, -1 on failure. If failed,
  1.5732 + *	use Tcl_GetErrno() to retrieve the POSIX error code for the
  1.5733 + *	error that occurred.
  1.5734 + *
  1.5735 + * Side effects:
  1.5736 + *	None.
  1.5737 + *
  1.5738 + *----------------------------------------------------------------------
  1.5739 + */
  1.5740 +
  1.5741 +EXPORT_C Tcl_WideInt
  1.5742 +Tcl_Tell(chan)
  1.5743 +    Tcl_Channel chan;			/* The channel to return pos for. */
  1.5744 +{
  1.5745 +    Channel *chanPtr = (Channel *) chan;	/* The real IO channel. */
  1.5746 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.5747 +    int inputBuffered, outputBuffered;	/* # bytes held in buffers. */
  1.5748 +    int result;				/* Of calling device driver. */
  1.5749 +    Tcl_WideInt curPos;			/* Position on device. */
  1.5750 +
  1.5751 +    if (CheckChannelErrors(statePtr, TCL_WRITABLE | TCL_READABLE) != 0) {
  1.5752 +	return Tcl_LongAsWide(-1);
  1.5753 +    }
  1.5754 +
  1.5755 +    /*
  1.5756 +     * Disallow tell on dead channels -- channels that have been closed but
  1.5757 +     * not yet been deallocated. Such channels can be found if the exit
  1.5758 +     * handler for channel cleanup has run but the channel is still
  1.5759 +     * registered in an interpreter.
  1.5760 +     */
  1.5761 +
  1.5762 +    if (CheckForDeadChannel(NULL, statePtr)) {
  1.5763 +	return Tcl_LongAsWide(-1);
  1.5764 +    }
  1.5765 +
  1.5766 +    /*
  1.5767 +     * This operation should occur at the top of a channel stack.
  1.5768 +     */
  1.5769 +
  1.5770 +    chanPtr = statePtr->topChanPtr;
  1.5771 +
  1.5772 +    /*
  1.5773 +     * Disallow tell on channels whose type does not have a seek procedure
  1.5774 +     * defined. This means that the channel does not support seeking.
  1.5775 +     */
  1.5776 +
  1.5777 +    if (chanPtr->typePtr->seekProc == (Tcl_DriverSeekProc *) NULL) {
  1.5778 +        Tcl_SetErrno(EINVAL);
  1.5779 +        return Tcl_LongAsWide(-1);
  1.5780 +    }
  1.5781 +
  1.5782 +    /*
  1.5783 +     * Compute how much input and output is buffered. If both input and
  1.5784 +     * output is buffered, cannot compute the current position.
  1.5785 +     */
  1.5786 +
  1.5787 +    inputBuffered = Tcl_InputBuffered(chan);
  1.5788 +    outputBuffered = Tcl_OutputBuffered(chan);
  1.5789 +
  1.5790 +    if ((inputBuffered != 0) && (outputBuffered != 0)) {
  1.5791 +        Tcl_SetErrno(EFAULT);
  1.5792 +        return Tcl_LongAsWide(-1);
  1.5793 +    }
  1.5794 +
  1.5795 +    /*
  1.5796 +     * Get the current position in the device and compute the position
  1.5797 +     * where the next character will be read or written.  Note that we
  1.5798 +     * prefer the wideSeekProc if that is available and non-NULL...
  1.5799 +     */
  1.5800 +
  1.5801 +    if (HaveVersion(chanPtr->typePtr, TCL_CHANNEL_VERSION_3) &&
  1.5802 +	    chanPtr->typePtr->wideSeekProc != NULL) {
  1.5803 +	curPos = (chanPtr->typePtr->wideSeekProc) (chanPtr->instanceData,
  1.5804 +		Tcl_LongAsWide(0), SEEK_CUR, &result);
  1.5805 +    } else {
  1.5806 +	curPos = Tcl_LongAsWide((chanPtr->typePtr->seekProc) (
  1.5807 +		chanPtr->instanceData, 0, SEEK_CUR, &result));
  1.5808 +    }
  1.5809 +    if (curPos == Tcl_LongAsWide(-1)) {
  1.5810 +        Tcl_SetErrno(result);
  1.5811 +        return Tcl_LongAsWide(-1);
  1.5812 +    }
  1.5813 +    if (inputBuffered != 0) {
  1.5814 +        return curPos - inputBuffered;
  1.5815 +    }
  1.5816 +    return curPos + outputBuffered;
  1.5817 +}
  1.5818 +
  1.5819 +/*
  1.5820 + *---------------------------------------------------------------------------
  1.5821 + *
  1.5822 + * Tcl_SeekOld, Tcl_TellOld --
  1.5823 + *
  1.5824 + *	Backward-compatability versions of the seek/tell interface that
  1.5825 + *	do not support 64-bit offsets.  This interface is not documented
  1.5826 + *	or expected to be supported indefinitely.
  1.5827 + *
  1.5828 + * Results:
  1.5829 + *	As for Tcl_Seek and Tcl_Tell respectively, except truncated to
  1.5830 + *	whatever value will fit in an 'int'.
  1.5831 + *
  1.5832 + * Side effects:
  1.5833 + *	As for Tcl_Seek and Tcl_Tell respectively.
  1.5834 + *
  1.5835 + *---------------------------------------------------------------------------
  1.5836 + */
  1.5837 +
  1.5838 +EXPORT_C int
  1.5839 +Tcl_SeekOld(chan, offset, mode)
  1.5840 +    Tcl_Channel chan;		/* The channel on which to seek. */
  1.5841 +    int offset;			/* Offset to seek to. */
  1.5842 +    int mode;			/* Relative to which location to seek? */
  1.5843 +{
  1.5844 +    Tcl_WideInt wOffset, wResult;
  1.5845 +
  1.5846 +    wOffset = Tcl_LongAsWide((long)offset);
  1.5847 +    wResult = Tcl_Seek(chan, wOffset, mode);
  1.5848 +    return (int)Tcl_WideAsLong(wResult);
  1.5849 +}
  1.5850 +
  1.5851 +EXPORT_C int
  1.5852 +Tcl_TellOld(chan)
  1.5853 +    Tcl_Channel chan;		/* The channel to return pos for. */
  1.5854 +{
  1.5855 +    Tcl_WideInt wResult;
  1.5856 +
  1.5857 +    wResult = Tcl_Tell(chan);
  1.5858 +    return (int)Tcl_WideAsLong(wResult);
  1.5859 +}
  1.5860 +
  1.5861 +/*
  1.5862 + *---------------------------------------------------------------------------
  1.5863 + *
  1.5864 + * CheckChannelErrors --
  1.5865 + *
  1.5866 + *	See if the channel is in an ready state and can perform the
  1.5867 + *	desired operation.
  1.5868 + *
  1.5869 + * Results:
  1.5870 + *	The return value is 0 if the channel is OK, otherwise the
  1.5871 + *	return value is -1 and errno is set to indicate the error.
  1.5872 + *
  1.5873 + * Side effects:
  1.5874 + *	May clear the EOF and/or BLOCKED bits if reading from channel.
  1.5875 + *
  1.5876 + *---------------------------------------------------------------------------
  1.5877 + */
  1.5878 + 
  1.5879 +static int
  1.5880 +CheckChannelErrors(statePtr, flags)
  1.5881 +    ChannelState *statePtr;	/* Channel to check. */
  1.5882 +    int flags;			/* Test if channel supports desired operation:
  1.5883 +				 * TCL_READABLE, TCL_WRITABLE.  Also indicates
  1.5884 +				 * Raw read or write for special close
  1.5885 +				 * processing*/
  1.5886 +{
  1.5887 +    int direction = flags & (TCL_READABLE|TCL_WRITABLE);
  1.5888 +
  1.5889 +    /*
  1.5890 +     * Check for unreported error.
  1.5891 +     */
  1.5892 +
  1.5893 +    if (statePtr->unreportedError != 0) {
  1.5894 +        Tcl_SetErrno(statePtr->unreportedError);
  1.5895 +        statePtr->unreportedError = 0;
  1.5896 +        return -1;
  1.5897 +    }
  1.5898 +
  1.5899 +    /*
  1.5900 +     * Only the raw read and write operations are allowed during close
  1.5901 +     * in order to drain data from stacked channels.
  1.5902 +     */
  1.5903 +
  1.5904 +    if ((statePtr->flags & CHANNEL_CLOSED) &&
  1.5905 +	    ((flags & CHANNEL_RAW_MODE) == 0)) {
  1.5906 +        Tcl_SetErrno(EACCES);
  1.5907 +        return -1;
  1.5908 +    }
  1.5909 +
  1.5910 +    /*
  1.5911 +     * Fail if the channel is not opened for desired operation.
  1.5912 +     */
  1.5913 +
  1.5914 +    if ((statePtr->flags & direction) == 0) {
  1.5915 +        Tcl_SetErrno(EACCES);
  1.5916 +        return -1;
  1.5917 +    }
  1.5918 +
  1.5919 +    /*
  1.5920 +     * Fail if the channel is in the middle of a background copy.
  1.5921 +     *
  1.5922 +     * Don't do this tests for raw channels here or else the chaining in the
  1.5923 +     * transformation drivers will fail with 'file busy' error instead of
  1.5924 +     * retrieving and transforming the data to copy.
  1.5925 +     */
  1.5926 +
  1.5927 +    if ((statePtr->csPtr != NULL) && ((flags & CHANNEL_RAW_MODE) == 0)) {
  1.5928 +	Tcl_SetErrno(EBUSY);
  1.5929 +	return -1;
  1.5930 +    }
  1.5931 +
  1.5932 +    if (direction == TCL_READABLE) {
  1.5933 +	/*
  1.5934 +	 * If we have not encountered a sticky EOF, clear the EOF bit
  1.5935 +	 * (sticky EOF is set if we have seen the input eofChar, to prevent
  1.5936 +	 * reading beyond the eofChar). Also, always clear the BLOCKED bit.
  1.5937 +	 * We want to discover these conditions anew in each operation.
  1.5938 +	 */
  1.5939 +
  1.5940 +	if ((statePtr->flags & CHANNEL_STICKY_EOF) == 0) {
  1.5941 +	    statePtr->flags &= ~CHANNEL_EOF;
  1.5942 +	}
  1.5943 +	statePtr->flags &= ~(CHANNEL_BLOCKED | CHANNEL_NEED_MORE_DATA);
  1.5944 +    }
  1.5945 +
  1.5946 +    return 0;
  1.5947 +}
  1.5948 +
  1.5949 +/*
  1.5950 + *----------------------------------------------------------------------
  1.5951 + *
  1.5952 + * Tcl_Eof --
  1.5953 + *
  1.5954 + *	Returns 1 if the channel is at EOF, 0 otherwise.
  1.5955 + *
  1.5956 + * Results:
  1.5957 + *	1 or 0, always.
  1.5958 + *
  1.5959 + * Side effects:
  1.5960 + *	None.
  1.5961 + *
  1.5962 + *----------------------------------------------------------------------
  1.5963 + */
  1.5964 +
  1.5965 +EXPORT_C int
  1.5966 +Tcl_Eof(chan)
  1.5967 +    Tcl_Channel chan;			/* Does this channel have EOF? */
  1.5968 +{
  1.5969 +    ChannelState *statePtr = ((Channel *) chan)->state;
  1.5970 +					/* State of real channel structure. */
  1.5971 +
  1.5972 +    return ((statePtr->flags & CHANNEL_STICKY_EOF) ||
  1.5973 +            ((statePtr->flags & CHANNEL_EOF) &&
  1.5974 +		    (Tcl_InputBuffered(chan) == 0))) ? 1 : 0;
  1.5975 +}
  1.5976 +
  1.5977 +/*
  1.5978 + *----------------------------------------------------------------------
  1.5979 + *
  1.5980 + * Tcl_InputBlocked --
  1.5981 + *
  1.5982 + *	Returns 1 if input is blocked on this channel, 0 otherwise.
  1.5983 + *
  1.5984 + * Results:
  1.5985 + *	0 or 1, always.
  1.5986 + *
  1.5987 + * Side effects:
  1.5988 + *	None.
  1.5989 + *
  1.5990 + *----------------------------------------------------------------------
  1.5991 + */
  1.5992 +
  1.5993 +EXPORT_C int
  1.5994 +Tcl_InputBlocked(chan)
  1.5995 +    Tcl_Channel chan;			/* Is this channel blocked? */
  1.5996 +{
  1.5997 +    ChannelState *statePtr = ((Channel *) chan)->state;
  1.5998 +					/* State of real channel structure. */
  1.5999 +
  1.6000 +    return (statePtr->flags & CHANNEL_BLOCKED) ? 1 : 0;
  1.6001 +}
  1.6002 +
  1.6003 +/*
  1.6004 + *----------------------------------------------------------------------
  1.6005 + *
  1.6006 + * Tcl_InputBuffered --
  1.6007 + *
  1.6008 + *	Returns the number of bytes of input currently buffered in the
  1.6009 + *	common internal buffer of a channel.
  1.6010 + *
  1.6011 + * Results:
  1.6012 + *	The number of input bytes buffered, or zero if the channel is not
  1.6013 + *	open for reading.
  1.6014 + *
  1.6015 + * Side effects:
  1.6016 + *	None.
  1.6017 + *
  1.6018 + *----------------------------------------------------------------------
  1.6019 + */
  1.6020 +
  1.6021 +EXPORT_C int
  1.6022 +Tcl_InputBuffered(chan)
  1.6023 +    Tcl_Channel chan;			/* The channel to query. */
  1.6024 +{
  1.6025 +    ChannelState *statePtr = ((Channel *) chan)->state;
  1.6026 +					/* State of real channel structure. */
  1.6027 +    ChannelBuffer *bufPtr;
  1.6028 +    int bytesBuffered;
  1.6029 +
  1.6030 +    for (bytesBuffered = 0, bufPtr = statePtr->inQueueHead;
  1.6031 +	 bufPtr != (ChannelBuffer *) NULL;
  1.6032 +	 bufPtr = bufPtr->nextPtr) {
  1.6033 +        bytesBuffered += (bufPtr->nextAdded - bufPtr->nextRemoved);
  1.6034 +    }
  1.6035 +
  1.6036 +    /*
  1.6037 +     * Don't forget the bytes in the topmost pushback area.
  1.6038 +     */
  1.6039 +
  1.6040 +    for (bufPtr = statePtr->topChanPtr->inQueueHead;
  1.6041 +	 bufPtr != (ChannelBuffer *) NULL;
  1.6042 +	 bufPtr = bufPtr->nextPtr) {
  1.6043 +        bytesBuffered += (bufPtr->nextAdded - bufPtr->nextRemoved);
  1.6044 +    }
  1.6045 +
  1.6046 +    return bytesBuffered;
  1.6047 +}
  1.6048 +
  1.6049 +/*
  1.6050 + *----------------------------------------------------------------------
  1.6051 + *
  1.6052 + * Tcl_OutputBuffered --
  1.6053 + *
  1.6054 + *    Returns the number of bytes of output currently buffered in the
  1.6055 + *    common internal buffer of a channel.
  1.6056 + *
  1.6057 + * Results:
  1.6058 + *    The number of output bytes buffered, or zero if the channel is not
  1.6059 + *    open for writing.
  1.6060 + *
  1.6061 + * Side effects:
  1.6062 + *    None.
  1.6063 + *
  1.6064 + *----------------------------------------------------------------------
  1.6065 + */
  1.6066 +
  1.6067 +EXPORT_C int
  1.6068 +Tcl_OutputBuffered(chan)
  1.6069 +    Tcl_Channel chan;                 /* The channel to query. */
  1.6070 +{
  1.6071 +    ChannelState *statePtr = ((Channel *) chan)->state;
  1.6072 +                                      /* State of real channel structure. */
  1.6073 +    ChannelBuffer *bufPtr;
  1.6074 +    int bytesBuffered;
  1.6075 +
  1.6076 +    for (bytesBuffered = 0, bufPtr = statePtr->outQueueHead;
  1.6077 +	bufPtr != (ChannelBuffer *) NULL;
  1.6078 +	bufPtr = bufPtr->nextPtr) {
  1.6079 +	bytesBuffered += (bufPtr->nextAdded - bufPtr->nextRemoved);
  1.6080 +    }
  1.6081 +    if ((statePtr->curOutPtr != (ChannelBuffer *) NULL) &&
  1.6082 +	(statePtr->curOutPtr->nextAdded > statePtr->curOutPtr->nextRemoved)) {
  1.6083 +	statePtr->flags |= BUFFER_READY;
  1.6084 +	bytesBuffered +=
  1.6085 +	    (statePtr->curOutPtr->nextAdded - statePtr->curOutPtr->nextRemoved);
  1.6086 +    }
  1.6087 +
  1.6088 +    return bytesBuffered;
  1.6089 +}
  1.6090 +
  1.6091 +/*
  1.6092 + *----------------------------------------------------------------------
  1.6093 + *
  1.6094 + * Tcl_ChannelBuffered --
  1.6095 + *
  1.6096 + *	Returns the number of bytes of input currently buffered in the
  1.6097 + *	internal buffer (push back area) of a channel.
  1.6098 + *
  1.6099 + * Results:
  1.6100 + *	The number of input bytes buffered, or zero if the channel is not
  1.6101 + *	open for reading.
  1.6102 + *
  1.6103 + * Side effects:
  1.6104 + *	None.
  1.6105 + *
  1.6106 + *----------------------------------------------------------------------
  1.6107 + */
  1.6108 +
  1.6109 +EXPORT_C int
  1.6110 +Tcl_ChannelBuffered(chan)
  1.6111 +    Tcl_Channel chan;			/* The channel to query. */
  1.6112 +{
  1.6113 +    Channel *chanPtr = (Channel *) chan;
  1.6114 +					/* real channel structure. */
  1.6115 +    ChannelBuffer *bufPtr;
  1.6116 +    int bytesBuffered;
  1.6117 +
  1.6118 +    for (bytesBuffered = 0, bufPtr = chanPtr->inQueueHead;
  1.6119 +	 bufPtr != (ChannelBuffer *) NULL;
  1.6120 +	 bufPtr = bufPtr->nextPtr) {
  1.6121 +        bytesBuffered += (bufPtr->nextAdded - bufPtr->nextRemoved);
  1.6122 +    }
  1.6123 +
  1.6124 +    return bytesBuffered;
  1.6125 +}
  1.6126 +
  1.6127 +/*
  1.6128 + *----------------------------------------------------------------------
  1.6129 + *
  1.6130 + * Tcl_SetChannelBufferSize --
  1.6131 + *
  1.6132 + *	Sets the size of buffers to allocate to store input or output
  1.6133 + *	in the channel. The size must be between 1 byte and 1 MByte.
  1.6134 + *
  1.6135 + * Results:
  1.6136 + *	None.
  1.6137 + *
  1.6138 + * Side effects:
  1.6139 + *	Sets the size of buffers subsequently allocated for this channel.
  1.6140 + *
  1.6141 + *----------------------------------------------------------------------
  1.6142 + */
  1.6143 +
  1.6144 +EXPORT_C void
  1.6145 +Tcl_SetChannelBufferSize(chan, sz)
  1.6146 +    Tcl_Channel chan;			/* The channel whose buffer size
  1.6147 +                                         * to set. */
  1.6148 +    int sz;				/* The size to set. */
  1.6149 +{
  1.6150 +    ChannelState *statePtr;		/* State of real channel structure. */
  1.6151 +    
  1.6152 +    /*
  1.6153 +     * If the buffer size is smaller than 1 byte or larger than one MByte,
  1.6154 +     * do not accept the requested size and leave the current buffer size.
  1.6155 +     */
  1.6156 +    
  1.6157 +    if (sz < 1) {
  1.6158 +        return;
  1.6159 +    }
  1.6160 +    if (sz > (1024 * 1024)) {
  1.6161 +        return;
  1.6162 +    }
  1.6163 +
  1.6164 +    statePtr = ((Channel *) chan)->state;
  1.6165 +    statePtr->bufSize = sz;
  1.6166 +
  1.6167 +    if (statePtr->outputStage != NULL) {
  1.6168 +	ckfree((char *) statePtr->outputStage);
  1.6169 +	statePtr->outputStage = NULL;
  1.6170 +    }
  1.6171 +    if ((statePtr->encoding != NULL) && (statePtr->flags & TCL_WRITABLE)) {
  1.6172 +	statePtr->outputStage = (char *)
  1.6173 +	    ckalloc((unsigned) (statePtr->bufSize + 2));
  1.6174 +    }
  1.6175 +}
  1.6176 +
  1.6177 +/*
  1.6178 + *----------------------------------------------------------------------
  1.6179 + *
  1.6180 + * Tcl_GetChannelBufferSize --
  1.6181 + *
  1.6182 + *	Retrieves the size of buffers to allocate for this channel.
  1.6183 + *
  1.6184 + * Results:
  1.6185 + *	The size.
  1.6186 + *
  1.6187 + * Side effects:
  1.6188 + *	None.
  1.6189 + *
  1.6190 + *----------------------------------------------------------------------
  1.6191 + */
  1.6192 +
  1.6193 +EXPORT_C int
  1.6194 +Tcl_GetChannelBufferSize(chan)
  1.6195 +    Tcl_Channel chan;		/* The channel for which to find the
  1.6196 +                                 * buffer size. */
  1.6197 +{
  1.6198 +    ChannelState *statePtr = ((Channel *) chan)->state;
  1.6199 +					/* State of real channel structure. */
  1.6200 +
  1.6201 +    return statePtr->bufSize;
  1.6202 +}
  1.6203 +
  1.6204 +/*
  1.6205 + *----------------------------------------------------------------------
  1.6206 + *
  1.6207 + * Tcl_BadChannelOption --
  1.6208 + *
  1.6209 + *	This procedure generates a "bad option" error message in an
  1.6210 + *	(optional) interpreter.  It is used by channel drivers when 
  1.6211 + *      a invalid Set/Get option is requested. Its purpose is to concatenate
  1.6212 + *      the generic options list to the specific ones and factorize
  1.6213 + *      the generic options error message string.
  1.6214 + *
  1.6215 + * Results:
  1.6216 + *	TCL_ERROR.
  1.6217 + *
  1.6218 + * Side effects:
  1.6219 + *	An error message is generated in interp's result object to
  1.6220 + *	indicate that a command was invoked with the a bad option
  1.6221 + *	The message has the form
  1.6222 + *		bad option "blah": should be one of 
  1.6223 + *              <...generic options...>+<...specific options...>
  1.6224 + *	"blah" is the optionName argument and "<specific options>"
  1.6225 + *	is a space separated list of specific option words.
  1.6226 + *      The function takes good care of inserting minus signs before
  1.6227 + *      each option, commas after, and an "or" before the last option.
  1.6228 + *
  1.6229 + *----------------------------------------------------------------------
  1.6230 + */
  1.6231 +
  1.6232 +EXPORT_C int
  1.6233 +Tcl_BadChannelOption(interp, optionName, optionList)
  1.6234 +    Tcl_Interp *interp;			/* Current interpreter. (can be NULL)*/
  1.6235 +    CONST char *optionName;		/* 'bad option' name */
  1.6236 +    CONST char *optionList;		/* Specific options list to append 
  1.6237 +					 * to the standard generic options.
  1.6238 +					 * can be NULL for generic options 
  1.6239 +					 * only.
  1.6240 +					 */
  1.6241 +{
  1.6242 +    if (interp) {
  1.6243 +	CONST char *genericopt = 
  1.6244 +	    "blocking buffering buffersize encoding eofchar translation";
  1.6245 +	CONST char **argv;
  1.6246 +	int  argc, i;
  1.6247 +	Tcl_DString ds;
  1.6248 +
  1.6249 +	Tcl_DStringInit(&ds);
  1.6250 +	Tcl_DStringAppend(&ds, genericopt, -1);
  1.6251 +	if (optionList && (*optionList)) {
  1.6252 +	    Tcl_DStringAppend(&ds, " ", 1);
  1.6253 +	    Tcl_DStringAppend(&ds, optionList, -1);
  1.6254 +	}
  1.6255 +	if (Tcl_SplitList(interp, Tcl_DStringValue(&ds), 
  1.6256 +		&argc, &argv) != TCL_OK) {
  1.6257 +	    panic("malformed option list in channel driver");
  1.6258 +	}
  1.6259 +	Tcl_ResetResult(interp);
  1.6260 +	Tcl_AppendResult(interp, "bad option \"", optionName, 
  1.6261 +		"\": should be one of ", (char *) NULL);
  1.6262 +	argc--;
  1.6263 +	for (i = 0; i < argc; i++) {
  1.6264 +	    Tcl_AppendResult(interp, "-", argv[i], ", ", (char *) NULL);
  1.6265 +	}
  1.6266 +	Tcl_AppendResult(interp, "or -", argv[i], (char *) NULL);
  1.6267 +	Tcl_DStringFree(&ds);
  1.6268 +	ckfree((char *) argv);
  1.6269 +    }
  1.6270 +    Tcl_SetErrno(EINVAL);
  1.6271 +    return TCL_ERROR;
  1.6272 +}
  1.6273 +
  1.6274 +/*
  1.6275 + *----------------------------------------------------------------------
  1.6276 + *
  1.6277 + * Tcl_GetChannelOption --
  1.6278 + *
  1.6279 + *	Gets a mode associated with an IO channel. If the optionName arg
  1.6280 + *	is non NULL, retrieves the value of that option. If the optionName
  1.6281 + *	arg is NULL, retrieves a list of alternating option names and
  1.6282 + *	values for the given channel.
  1.6283 + *
  1.6284 + * Results:
  1.6285 + *	A standard Tcl result. Also sets the supplied DString to the
  1.6286 + *	string value of the option(s) returned.
  1.6287 + *
  1.6288 + * Side effects:
  1.6289 + *      None.
  1.6290 + *
  1.6291 + *----------------------------------------------------------------------
  1.6292 + */
  1.6293 +
  1.6294 +EXPORT_C int
  1.6295 +Tcl_GetChannelOption(interp, chan, optionName, dsPtr)
  1.6296 +    Tcl_Interp *interp;		/* For error reporting - can be NULL. */
  1.6297 +    Tcl_Channel chan;		/* Channel on which to get option. */
  1.6298 +    CONST char *optionName;	/* Option to get. */
  1.6299 +    Tcl_DString *dsPtr;		/* Where to store value(s). */
  1.6300 +{
  1.6301 +    size_t len;			/* Length of optionName string. */
  1.6302 +    char optionVal[128];	/* Buffer for sprintf. */
  1.6303 +    Channel *chanPtr = (Channel *) chan;
  1.6304 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.6305 +    int flags;
  1.6306 +
  1.6307 +    /*
  1.6308 +     * Disallow options on dead channels -- channels that have been closed but
  1.6309 +     * not yet been deallocated. Such channels can be found if the exit
  1.6310 +     * handler for channel cleanup has run but the channel is still
  1.6311 +     * registered in an interpreter.
  1.6312 +     */
  1.6313 +
  1.6314 +    if (CheckForDeadChannel(interp, statePtr)) {
  1.6315 +	return TCL_ERROR;
  1.6316 +    }
  1.6317 +
  1.6318 +    /*
  1.6319 +     * This operation should occur at the top of a channel stack.
  1.6320 +     */
  1.6321 +
  1.6322 +    chanPtr = statePtr->topChanPtr;
  1.6323 +
  1.6324 +    /*
  1.6325 +     * If we are in the middle of a background copy, use the saved flags.
  1.6326 +     */
  1.6327 +
  1.6328 +    if (statePtr->csPtr) {
  1.6329 +	if (chanPtr == statePtr->csPtr->readPtr) {
  1.6330 +	    flags = statePtr->csPtr->readFlags;
  1.6331 +	} else {
  1.6332 +	    flags = statePtr->csPtr->writeFlags;
  1.6333 +	}
  1.6334 +    } else {
  1.6335 +	flags = statePtr->flags;
  1.6336 +    }
  1.6337 +
  1.6338 +    /*
  1.6339 +     * If the optionName is NULL it means that we want a list of all
  1.6340 +     * options and values.
  1.6341 +     */
  1.6342 +    
  1.6343 +    if (optionName == (char *) NULL) {
  1.6344 +        len = 0;
  1.6345 +    } else {
  1.6346 +        len = strlen(optionName);
  1.6347 +    }
  1.6348 +    
  1.6349 +    if ((len == 0) || ((len > 2) && (optionName[1] == 'b') &&
  1.6350 +            (strncmp(optionName, "-blocking", len) == 0))) {
  1.6351 +        if (len == 0) {
  1.6352 +            Tcl_DStringAppendElement(dsPtr, "-blocking");
  1.6353 +        }
  1.6354 +        Tcl_DStringAppendElement(dsPtr,
  1.6355 +		(flags & CHANNEL_NONBLOCKING) ? "0" : "1");
  1.6356 +        if (len > 0) {
  1.6357 +            return TCL_OK;
  1.6358 +        }
  1.6359 +    }
  1.6360 +    if ((len == 0) || ((len > 7) && (optionName[1] == 'b') &&
  1.6361 +            (strncmp(optionName, "-buffering", len) == 0))) {
  1.6362 +        if (len == 0) {
  1.6363 +            Tcl_DStringAppendElement(dsPtr, "-buffering");
  1.6364 +        }
  1.6365 +        if (flags & CHANNEL_LINEBUFFERED) {
  1.6366 +            Tcl_DStringAppendElement(dsPtr, "line");
  1.6367 +        } else if (flags & CHANNEL_UNBUFFERED) {
  1.6368 +            Tcl_DStringAppendElement(dsPtr, "none");
  1.6369 +        } else {
  1.6370 +            Tcl_DStringAppendElement(dsPtr, "full");
  1.6371 +        }
  1.6372 +        if (len > 0) {
  1.6373 +            return TCL_OK;
  1.6374 +        }
  1.6375 +    }
  1.6376 +    if ((len == 0) || ((len > 7) && (optionName[1] == 'b') &&
  1.6377 +            (strncmp(optionName, "-buffersize", len) == 0))) {
  1.6378 +        if (len == 0) {
  1.6379 +            Tcl_DStringAppendElement(dsPtr, "-buffersize");
  1.6380 +        }
  1.6381 +        TclFormatInt(optionVal, statePtr->bufSize);
  1.6382 +        Tcl_DStringAppendElement(dsPtr, optionVal);
  1.6383 +        if (len > 0) {
  1.6384 +            return TCL_OK;
  1.6385 +        }
  1.6386 +    }
  1.6387 +    if ((len == 0) ||
  1.6388 +	    ((len > 2) && (optionName[1] == 'e') &&
  1.6389 +		    (strncmp(optionName, "-encoding", len) == 0))) {
  1.6390 +	if (len == 0) {
  1.6391 +	    Tcl_DStringAppendElement(dsPtr, "-encoding");
  1.6392 +	}
  1.6393 +	if (statePtr->encoding == NULL) {
  1.6394 +	    Tcl_DStringAppendElement(dsPtr, "binary");
  1.6395 +	} else {
  1.6396 +	    Tcl_DStringAppendElement(dsPtr,
  1.6397 +		    Tcl_GetEncodingName(statePtr->encoding));
  1.6398 +	}
  1.6399 +	if (len > 0) {
  1.6400 +	    return TCL_OK;
  1.6401 +	}
  1.6402 +    }
  1.6403 +    if ((len == 0) ||
  1.6404 +            ((len > 2) && (optionName[1] == 'e') &&
  1.6405 +                    (strncmp(optionName, "-eofchar", len) == 0))) {
  1.6406 +        if (len == 0) {
  1.6407 +            Tcl_DStringAppendElement(dsPtr, "-eofchar");
  1.6408 +        }
  1.6409 +        if (((flags & (TCL_READABLE|TCL_WRITABLE)) ==
  1.6410 +                (TCL_READABLE|TCL_WRITABLE)) && (len == 0)) {
  1.6411 +            Tcl_DStringStartSublist(dsPtr);
  1.6412 +        }
  1.6413 +        if (flags & TCL_READABLE) {
  1.6414 +            if (statePtr->inEofChar == 0) {
  1.6415 +                Tcl_DStringAppendElement(dsPtr, "");
  1.6416 +            } else {
  1.6417 +                char buf[4];
  1.6418 +
  1.6419 +                sprintf(buf, "%c", statePtr->inEofChar);
  1.6420 +                Tcl_DStringAppendElement(dsPtr, buf);
  1.6421 +            }
  1.6422 +        }
  1.6423 +        if (flags & TCL_WRITABLE) {
  1.6424 +            if (statePtr->outEofChar == 0) {
  1.6425 +                Tcl_DStringAppendElement(dsPtr, "");
  1.6426 +            } else {
  1.6427 +                char buf[4];
  1.6428 +
  1.6429 +                sprintf(buf, "%c", statePtr->outEofChar);
  1.6430 +                Tcl_DStringAppendElement(dsPtr, buf);
  1.6431 +            }
  1.6432 +        }
  1.6433 +        if ( !(flags & (TCL_READABLE|TCL_WRITABLE))) {
  1.6434 +            /* Not readable or writable (server socket) */
  1.6435 +            Tcl_DStringAppendElement(dsPtr, "");
  1.6436 +        }
  1.6437 +        if (((flags & (TCL_READABLE|TCL_WRITABLE)) ==
  1.6438 +                (TCL_READABLE|TCL_WRITABLE)) && (len == 0)) {
  1.6439 +            Tcl_DStringEndSublist(dsPtr);
  1.6440 +        }
  1.6441 +        if (len > 0) {
  1.6442 +            return TCL_OK;
  1.6443 +        }
  1.6444 +    }
  1.6445 +    if ((len == 0) ||
  1.6446 +            ((len > 1) && (optionName[1] == 't') &&
  1.6447 +                    (strncmp(optionName, "-translation", len) == 0))) {
  1.6448 +        if (len == 0) {
  1.6449 +            Tcl_DStringAppendElement(dsPtr, "-translation");
  1.6450 +        }
  1.6451 +        if (((flags & (TCL_READABLE|TCL_WRITABLE)) ==
  1.6452 +                (TCL_READABLE|TCL_WRITABLE)) && (len == 0)) {
  1.6453 +            Tcl_DStringStartSublist(dsPtr);
  1.6454 +        }
  1.6455 +        if (flags & TCL_READABLE) {
  1.6456 +            if (statePtr->inputTranslation == TCL_TRANSLATE_AUTO) {
  1.6457 +                Tcl_DStringAppendElement(dsPtr, "auto");
  1.6458 +            } else if (statePtr->inputTranslation == TCL_TRANSLATE_CR) {
  1.6459 +                Tcl_DStringAppendElement(dsPtr, "cr");
  1.6460 +            } else if (statePtr->inputTranslation == TCL_TRANSLATE_CRLF) {
  1.6461 +                Tcl_DStringAppendElement(dsPtr, "crlf");
  1.6462 +            } else {
  1.6463 +                Tcl_DStringAppendElement(dsPtr, "lf");
  1.6464 +            }
  1.6465 +        }
  1.6466 +        if (flags & TCL_WRITABLE) {
  1.6467 +            if (statePtr->outputTranslation == TCL_TRANSLATE_AUTO) {
  1.6468 +                Tcl_DStringAppendElement(dsPtr, "auto");
  1.6469 +            } else if (statePtr->outputTranslation == TCL_TRANSLATE_CR) {
  1.6470 +                Tcl_DStringAppendElement(dsPtr, "cr");
  1.6471 +            } else if (statePtr->outputTranslation == TCL_TRANSLATE_CRLF) {
  1.6472 +                Tcl_DStringAppendElement(dsPtr, "crlf");
  1.6473 +            } else {
  1.6474 +                Tcl_DStringAppendElement(dsPtr, "lf");
  1.6475 +            }
  1.6476 +        }
  1.6477 +        if ( !(flags & (TCL_READABLE|TCL_WRITABLE))) {
  1.6478 +            /* Not readable or writable (server socket) */
  1.6479 +            Tcl_DStringAppendElement(dsPtr, "auto");
  1.6480 +        }
  1.6481 +        if (((flags & (TCL_READABLE|TCL_WRITABLE)) ==
  1.6482 +                (TCL_READABLE|TCL_WRITABLE)) && (len == 0)) {
  1.6483 +            Tcl_DStringEndSublist(dsPtr);
  1.6484 +        }
  1.6485 +        if (len > 0) {
  1.6486 +            return TCL_OK;
  1.6487 +        }
  1.6488 +    }
  1.6489 +    if (chanPtr->typePtr->getOptionProc != (Tcl_DriverGetOptionProc *) NULL) {
  1.6490 +	/*
  1.6491 +	 * let the driver specific handle additional options
  1.6492 +	 * and result code and message.
  1.6493 +	 */
  1.6494 +
  1.6495 +        return (chanPtr->typePtr->getOptionProc) (chanPtr->instanceData,
  1.6496 +		interp, optionName, dsPtr);
  1.6497 +    } else {
  1.6498 +	/*
  1.6499 +	 * no driver specific options case.
  1.6500 +	 */
  1.6501 +
  1.6502 +        if (len == 0) {
  1.6503 +            return TCL_OK;
  1.6504 +        }
  1.6505 +	return Tcl_BadChannelOption(interp, optionName, NULL);
  1.6506 +    }
  1.6507 +}
  1.6508 +
  1.6509 +/*
  1.6510 + *---------------------------------------------------------------------------
  1.6511 + *
  1.6512 + * Tcl_SetChannelOption --
  1.6513 + *
  1.6514 + *	Sets an option on a channel.
  1.6515 + *
  1.6516 + * Results:
  1.6517 + *	A standard Tcl result.  On error, sets interp's result object
  1.6518 + *	if interp is not NULL.
  1.6519 + *
  1.6520 + * Side effects:
  1.6521 + *	May modify an option on a device.
  1.6522 + *
  1.6523 + *---------------------------------------------------------------------------
  1.6524 + */
  1.6525 +
  1.6526 +EXPORT_C int
  1.6527 +Tcl_SetChannelOption(interp, chan, optionName, newValue)
  1.6528 +    Tcl_Interp *interp;		/* For error reporting - can be NULL. */
  1.6529 +    Tcl_Channel chan;		/* Channel on which to set mode. */
  1.6530 +    CONST char *optionName;	/* Which option to set? */
  1.6531 +    CONST char *newValue;	/* New value for option. */
  1.6532 +{
  1.6533 +    Channel *chanPtr = (Channel *) chan;	/* The real IO channel. */
  1.6534 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.6535 +    size_t len;			/* Length of optionName string. */
  1.6536 +    int argc;
  1.6537 +    CONST char **argv;
  1.6538 +
  1.6539 +    /*
  1.6540 +     * If the channel is in the middle of a background copy, fail.
  1.6541 +     */
  1.6542 +
  1.6543 +    if (statePtr->csPtr) {
  1.6544 +	if (interp) {
  1.6545 +	    Tcl_AppendResult(interp,
  1.6546 +		    "unable to set channel options: background copy in progress",
  1.6547 +		    (char *) NULL);
  1.6548 +	}
  1.6549 +        return TCL_ERROR;
  1.6550 +    }
  1.6551 +
  1.6552 +    /*
  1.6553 +     * Disallow options on dead channels -- channels that have been closed but
  1.6554 +     * not yet been deallocated. Such channels can be found if the exit
  1.6555 +     * handler for channel cleanup has run but the channel is still
  1.6556 +     * registered in an interpreter.
  1.6557 +     */
  1.6558 +
  1.6559 +    if (CheckForDeadChannel(NULL, statePtr)) {
  1.6560 +	return TCL_ERROR;
  1.6561 +    }
  1.6562 +
  1.6563 +    /*
  1.6564 +     * This operation should occur at the top of a channel stack.
  1.6565 +     */
  1.6566 +
  1.6567 +    chanPtr = statePtr->topChanPtr;
  1.6568 +
  1.6569 +    len = strlen(optionName);
  1.6570 +
  1.6571 +    if ((len > 2) && (optionName[1] == 'b') &&
  1.6572 +            (strncmp(optionName, "-blocking", len) == 0)) {
  1.6573 +	int newMode;
  1.6574 +        if (Tcl_GetBoolean(interp, newValue, &newMode) == TCL_ERROR) {
  1.6575 +            return TCL_ERROR;
  1.6576 +        }
  1.6577 +        if (newMode) {
  1.6578 +            newMode = TCL_MODE_BLOCKING;
  1.6579 +        } else {
  1.6580 +            newMode = TCL_MODE_NONBLOCKING;
  1.6581 +        }
  1.6582 +	return SetBlockMode(interp, chanPtr, newMode);
  1.6583 +    } else if ((len > 7) && (optionName[1] == 'b') &&
  1.6584 +            (strncmp(optionName, "-buffering", len) == 0)) {
  1.6585 +        len = strlen(newValue);
  1.6586 +        if ((newValue[0] == 'f') && (strncmp(newValue, "full", len) == 0)) {
  1.6587 +            statePtr->flags &=
  1.6588 +                (~(CHANNEL_UNBUFFERED|CHANNEL_LINEBUFFERED));
  1.6589 +        } else if ((newValue[0] == 'l') &&
  1.6590 +                (strncmp(newValue, "line", len) == 0)) {
  1.6591 +            statePtr->flags &= (~(CHANNEL_UNBUFFERED));
  1.6592 +            statePtr->flags |= CHANNEL_LINEBUFFERED;
  1.6593 +        } else if ((newValue[0] == 'n') &&
  1.6594 +                (strncmp(newValue, "none", len) == 0)) {
  1.6595 +            statePtr->flags &= (~(CHANNEL_LINEBUFFERED));
  1.6596 +            statePtr->flags |= CHANNEL_UNBUFFERED;
  1.6597 +        } else {
  1.6598 +            if (interp) {
  1.6599 +                Tcl_AppendResult(interp, "bad value for -buffering: ",
  1.6600 +                        "must be one of full, line, or none",
  1.6601 +                        (char *) NULL);
  1.6602 +                return TCL_ERROR;
  1.6603 +            }
  1.6604 +        }
  1.6605 +	return TCL_OK;
  1.6606 +    } else if ((len > 7) && (optionName[1] == 'b') &&
  1.6607 +            (strncmp(optionName, "-buffersize", len) == 0)) {
  1.6608 +	int newBufferSize;
  1.6609 +	if (Tcl_GetInt(interp, newValue, &newBufferSize) == TCL_ERROR) {
  1.6610 +	    return TCL_ERROR;
  1.6611 +	}
  1.6612 +	Tcl_SetChannelBufferSize(chan, newBufferSize);
  1.6613 +    } else if ((len > 2) && (optionName[1] == 'e') &&
  1.6614 +	    (strncmp(optionName, "-encoding", len) == 0)) {
  1.6615 +	Tcl_Encoding encoding;
  1.6616 +
  1.6617 +	if ((newValue[0] == '\0') || (strcmp(newValue, "binary") == 0)) {
  1.6618 +	    encoding = NULL;
  1.6619 +	} else {
  1.6620 +	    encoding = Tcl_GetEncoding(interp, newValue);
  1.6621 +	    if (encoding == NULL) {
  1.6622 +		return TCL_ERROR;
  1.6623 +	    }
  1.6624 +	}
  1.6625 +	/*
  1.6626 +	 * When the channel has an escape sequence driven encoding such as
  1.6627 +	 * iso2022, the terminated escape sequence must write to the buffer.
  1.6628 +	 */
  1.6629 +	if ((statePtr->encoding != NULL) && (statePtr->curOutPtr != NULL)
  1.6630 +		&& (CheckChannelErrors(statePtr, TCL_WRITABLE) == 0)) {
  1.6631 +	    statePtr->outputEncodingFlags |= TCL_ENCODING_END;
  1.6632 +	    WriteChars(chanPtr, "", 0);
  1.6633 +	}
  1.6634 +	Tcl_FreeEncoding(statePtr->encoding);
  1.6635 +	statePtr->encoding = encoding;
  1.6636 +	statePtr->inputEncodingState = NULL;
  1.6637 +	statePtr->inputEncodingFlags = TCL_ENCODING_START;
  1.6638 +	statePtr->outputEncodingState = NULL;
  1.6639 +	statePtr->outputEncodingFlags = TCL_ENCODING_START;
  1.6640 +	statePtr->flags &= ~CHANNEL_NEED_MORE_DATA;
  1.6641 +	UpdateInterest(chanPtr);
  1.6642 +    } else if ((len > 2) && (optionName[1] == 'e') &&
  1.6643 +            (strncmp(optionName, "-eofchar", len) == 0)) {
  1.6644 +        if (Tcl_SplitList(interp, newValue, &argc, &argv) == TCL_ERROR) {
  1.6645 +            return TCL_ERROR;
  1.6646 +        }
  1.6647 +        if (argc == 0) {
  1.6648 +            statePtr->inEofChar = 0;
  1.6649 +            statePtr->outEofChar = 0;
  1.6650 +        } else if (argc == 1) {
  1.6651 +            if (statePtr->flags & TCL_WRITABLE) {
  1.6652 +                statePtr->outEofChar = (int) argv[0][0];
  1.6653 +            }
  1.6654 +            if (statePtr->flags & TCL_READABLE) {
  1.6655 +                statePtr->inEofChar = (int) argv[0][0];
  1.6656 +            }
  1.6657 +        } else if (argc != 2) {
  1.6658 +            if (interp) {
  1.6659 +                Tcl_AppendResult(interp,
  1.6660 +                        "bad value for -eofchar: should be a list of zero,",
  1.6661 +                        " one, or two elements", (char *) NULL);
  1.6662 +            }
  1.6663 +            ckfree((char *) argv);
  1.6664 +            return TCL_ERROR;
  1.6665 +        } else {
  1.6666 +            if (statePtr->flags & TCL_READABLE) {
  1.6667 +                statePtr->inEofChar = (int) argv[0][0];
  1.6668 +            }
  1.6669 +            if (statePtr->flags & TCL_WRITABLE) {
  1.6670 +                statePtr->outEofChar = (int) argv[1][0];
  1.6671 +            }
  1.6672 +        }
  1.6673 +        if (argv != NULL) {
  1.6674 +            ckfree((char *) argv);
  1.6675 +        }
  1.6676 +
  1.6677 +	/*
  1.6678 +	 * [SF Tcl Bug 930851] Reset EOF and BLOCKED flags. Changing
  1.6679 +	 * the character which signals eof can transform a current eof
  1.6680 +	 * condition into a 'go ahead'. Ditto for blocked.
  1.6681 +	 */
  1.6682 +
  1.6683 +	statePtr->flags &= (~(CHANNEL_EOF | CHANNEL_STICKY_EOF | CHANNEL_BLOCKED));
  1.6684 +
  1.6685 +	return TCL_OK;
  1.6686 +    } else if ((len > 1) && (optionName[1] == 't') &&
  1.6687 +            (strncmp(optionName, "-translation", len) == 0)) {
  1.6688 +	CONST char *readMode, *writeMode;
  1.6689 +
  1.6690 +        if (Tcl_SplitList(interp, newValue, &argc, &argv) == TCL_ERROR) {
  1.6691 +            return TCL_ERROR;
  1.6692 +        }
  1.6693 +
  1.6694 +        if (argc == 1) {
  1.6695 +	    readMode = (statePtr->flags & TCL_READABLE) ? argv[0] : NULL;
  1.6696 +	    writeMode = (statePtr->flags & TCL_WRITABLE) ? argv[0] : NULL;
  1.6697 +	} else if (argc == 2) {
  1.6698 +	    readMode = (statePtr->flags & TCL_READABLE) ? argv[0] : NULL;
  1.6699 +	    writeMode = (statePtr->flags & TCL_WRITABLE) ? argv[1] : NULL;
  1.6700 +	} else {
  1.6701 +            if (interp) {
  1.6702 +                Tcl_AppendResult(interp,
  1.6703 +                        "bad value for -translation: must be a one or two",
  1.6704 +                        " element list", (char *) NULL);
  1.6705 +            }
  1.6706 +            ckfree((char *) argv);
  1.6707 +            return TCL_ERROR;
  1.6708 +	}
  1.6709 +
  1.6710 +	if (readMode) {
  1.6711 +	    TclEolTranslation translation;
  1.6712 +	    if (*readMode == '\0') {
  1.6713 +		translation = statePtr->inputTranslation;
  1.6714 +	    } else if (strcmp(readMode, "auto") == 0) {
  1.6715 +		translation = TCL_TRANSLATE_AUTO;
  1.6716 +	    } else if (strcmp(readMode, "binary") == 0) {
  1.6717 +		translation = TCL_TRANSLATE_LF;
  1.6718 +		statePtr->inEofChar = 0;
  1.6719 +		Tcl_FreeEncoding(statePtr->encoding);		    
  1.6720 +		statePtr->encoding = NULL;
  1.6721 +	    } else if (strcmp(readMode, "lf") == 0) {
  1.6722 +		translation = TCL_TRANSLATE_LF;
  1.6723 +	    } else if (strcmp(readMode, "cr") == 0) {
  1.6724 +		translation = TCL_TRANSLATE_CR;
  1.6725 +	    } else if (strcmp(readMode, "crlf") == 0) {
  1.6726 +		translation = TCL_TRANSLATE_CRLF;
  1.6727 +	    } else if (strcmp(readMode, "platform") == 0) {
  1.6728 +		translation = TCL_PLATFORM_TRANSLATION;
  1.6729 +	    } else {
  1.6730 +		if (interp) {
  1.6731 +		    Tcl_AppendResult(interp,
  1.6732 +			    "bad value for -translation: ",
  1.6733 +			    "must be one of auto, binary, cr, lf, crlf,",
  1.6734 +			    " or platform", (char *) NULL);
  1.6735 +		}
  1.6736 +		ckfree((char *) argv);
  1.6737 +		return TCL_ERROR;
  1.6738 +	    }
  1.6739 +
  1.6740 +	    /*
  1.6741 +	     * Reset the EOL flags since we need to look at any buffered
  1.6742 +	     * data to see if the new translation mode allows us to
  1.6743 +	     * complete the line.
  1.6744 +	     */
  1.6745 +
  1.6746 +	    if (translation != statePtr->inputTranslation) {
  1.6747 +		statePtr->inputTranslation = translation;
  1.6748 +		statePtr->flags &= ~(INPUT_SAW_CR);
  1.6749 +		statePtr->flags &= ~(CHANNEL_NEED_MORE_DATA);
  1.6750 +		UpdateInterest(chanPtr);
  1.6751 +	    }
  1.6752 +	}
  1.6753 +	if (writeMode) {
  1.6754 +	    if (*writeMode == '\0') {
  1.6755 +		/* Do nothing. */
  1.6756 +	    } else if (strcmp(writeMode, "auto") == 0) {
  1.6757 +		/*
  1.6758 +		 * This is a hack to get TCP sockets to produce output
  1.6759 +		 * in CRLF mode if they are being set into AUTO mode.
  1.6760 +		 * A better solution for achieving this effect will be
  1.6761 +		 * coded later.
  1.6762 +		 */
  1.6763 +
  1.6764 +		if (strcmp(Tcl_ChannelName(chanPtr->typePtr), "tcp") == 0) {
  1.6765 +		    statePtr->outputTranslation = TCL_TRANSLATE_CRLF;
  1.6766 +		} else {
  1.6767 +		    statePtr->outputTranslation = TCL_PLATFORM_TRANSLATION;
  1.6768 +		}
  1.6769 +	    } else if (strcmp(writeMode, "binary") == 0) {
  1.6770 +		statePtr->outEofChar = 0;
  1.6771 +		statePtr->outputTranslation = TCL_TRANSLATE_LF;
  1.6772 +		Tcl_FreeEncoding(statePtr->encoding);		    
  1.6773 +		statePtr->encoding = NULL;
  1.6774 +	    } else if (strcmp(writeMode, "lf") == 0) {
  1.6775 +		statePtr->outputTranslation = TCL_TRANSLATE_LF;
  1.6776 +	    } else if (strcmp(writeMode, "cr") == 0) {
  1.6777 +		statePtr->outputTranslation = TCL_TRANSLATE_CR;
  1.6778 +	    } else if (strcmp(writeMode, "crlf") == 0) {
  1.6779 +		statePtr->outputTranslation = TCL_TRANSLATE_CRLF;
  1.6780 +	    } else if (strcmp(writeMode, "platform") == 0) {
  1.6781 +		statePtr->outputTranslation = TCL_PLATFORM_TRANSLATION;
  1.6782 +	    } else {
  1.6783 +		if (interp) {
  1.6784 +		    Tcl_AppendResult(interp,
  1.6785 +			    "bad value for -translation: ",
  1.6786 +			    "must be one of auto, binary, cr, lf, crlf,",
  1.6787 +			    " or platform", (char *) NULL);
  1.6788 +		}
  1.6789 +		ckfree((char *) argv);
  1.6790 +		return TCL_ERROR;
  1.6791 +	    }
  1.6792 +	}
  1.6793 +        ckfree((char *) argv);            
  1.6794 +        return TCL_OK;
  1.6795 +    } else if (chanPtr->typePtr->setOptionProc != NULL) {
  1.6796 +        return (*chanPtr->typePtr->setOptionProc)(chanPtr->instanceData,
  1.6797 +                interp, optionName, newValue);
  1.6798 +    } else {
  1.6799 +	return Tcl_BadChannelOption(interp, optionName, (char *) NULL);
  1.6800 +    }
  1.6801 +
  1.6802 +    /*
  1.6803 +     * If bufsize changes, need to get rid of old utility buffer.
  1.6804 +     */
  1.6805 +
  1.6806 +    if (statePtr->saveInBufPtr != NULL) {
  1.6807 +	RecycleBuffer(statePtr, statePtr->saveInBufPtr, 1);
  1.6808 +	statePtr->saveInBufPtr = NULL;
  1.6809 +    }
  1.6810 +    if (statePtr->inQueueHead != NULL) {
  1.6811 +	if ((statePtr->inQueueHead->nextPtr == NULL)
  1.6812 +		&& (statePtr->inQueueHead->nextAdded ==
  1.6813 +			statePtr->inQueueHead->nextRemoved)) {
  1.6814 +	    RecycleBuffer(statePtr, statePtr->inQueueHead, 1);
  1.6815 +	    statePtr->inQueueHead = NULL;
  1.6816 +	    statePtr->inQueueTail = NULL;
  1.6817 +	}
  1.6818 +    }
  1.6819 +
  1.6820 +    /*
  1.6821 +     * If encoding or bufsize changes, need to update output staging buffer.
  1.6822 +     */
  1.6823 +
  1.6824 +    if (statePtr->outputStage != NULL) {
  1.6825 +	ckfree((char *) statePtr->outputStage);
  1.6826 +	statePtr->outputStage = NULL;
  1.6827 +    }
  1.6828 +    if ((statePtr->encoding != NULL) && (statePtr->flags & TCL_WRITABLE)) {
  1.6829 +	statePtr->outputStage = (char *) 
  1.6830 +	    ckalloc((unsigned) (statePtr->bufSize + 2));
  1.6831 +    }
  1.6832 +    return TCL_OK;
  1.6833 +}
  1.6834 +
  1.6835 +/*
  1.6836 + *----------------------------------------------------------------------
  1.6837 + *
  1.6838 + * CleanupChannelHandlers --
  1.6839 + *
  1.6840 + *	Removes channel handlers that refer to the supplied interpreter,
  1.6841 + *	so that if the actual channel is not closed now, these handlers
  1.6842 + *	will not run on subsequent events on the channel. This would be
  1.6843 + *	erroneous, because the interpreter no longer has a reference to
  1.6844 + *	this channel.
  1.6845 + *
  1.6846 + * Results:
  1.6847 + *	None.
  1.6848 + *
  1.6849 + * Side effects:
  1.6850 + *	Removes channel handlers.
  1.6851 + *
  1.6852 + *----------------------------------------------------------------------
  1.6853 + */
  1.6854 +
  1.6855 +static void
  1.6856 +CleanupChannelHandlers(interp, chanPtr)
  1.6857 +    Tcl_Interp *interp;
  1.6858 +    Channel *chanPtr;
  1.6859 +{
  1.6860 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.6861 +    EventScriptRecord *sPtr, *prevPtr, *nextPtr;
  1.6862 +
  1.6863 +    /*
  1.6864 +     * Remove fileevent records on this channel that refer to the
  1.6865 +     * given interpreter.
  1.6866 +     */
  1.6867 +    
  1.6868 +    for (sPtr = statePtr->scriptRecordPtr,
  1.6869 +             prevPtr = (EventScriptRecord *) NULL;
  1.6870 +	 sPtr != (EventScriptRecord *) NULL;
  1.6871 +	 sPtr = nextPtr) {
  1.6872 +        nextPtr = sPtr->nextPtr;
  1.6873 +        if (sPtr->interp == interp) {
  1.6874 +            if (prevPtr == (EventScriptRecord *) NULL) {
  1.6875 +                statePtr->scriptRecordPtr = nextPtr;
  1.6876 +            } else {
  1.6877 +                prevPtr->nextPtr = nextPtr;
  1.6878 +            }
  1.6879 +
  1.6880 +            Tcl_DeleteChannelHandler((Tcl_Channel) chanPtr,
  1.6881 +                    TclChannelEventScriptInvoker, (ClientData) sPtr);
  1.6882 +
  1.6883 +	    Tcl_DecrRefCount(sPtr->scriptPtr);
  1.6884 +            ckfree((char *) sPtr);
  1.6885 +        } else {
  1.6886 +            prevPtr = sPtr;
  1.6887 +        }
  1.6888 +    }
  1.6889 +}
  1.6890 +
  1.6891 +/*
  1.6892 + *----------------------------------------------------------------------
  1.6893 + *
  1.6894 + * Tcl_NotifyChannel --
  1.6895 + *
  1.6896 + *	This procedure is called by a channel driver when a driver
  1.6897 + *	detects an event on a channel.  This procedure is responsible
  1.6898 + *	for actually handling the event by invoking any channel
  1.6899 + *	handler callbacks.
  1.6900 + *
  1.6901 + * Results:
  1.6902 + *	None.
  1.6903 + *
  1.6904 + * Side effects:
  1.6905 + *	Whatever the channel handler callback procedure does.
  1.6906 + *
  1.6907 + *----------------------------------------------------------------------
  1.6908 + */
  1.6909 +
  1.6910 +EXPORT_C void
  1.6911 +Tcl_NotifyChannel(channel, mask)
  1.6912 +    Tcl_Channel channel;	/* Channel that detected an event. */
  1.6913 +    int mask;			/* OR'ed combination of TCL_READABLE,
  1.6914 +				 * TCL_WRITABLE, or TCL_EXCEPTION: indicates
  1.6915 +				 * which events were detected. */
  1.6916 +{
  1.6917 +    Channel *chanPtr = (Channel *) channel;
  1.6918 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.6919 +    ChannelHandler *chPtr;
  1.6920 +    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
  1.6921 +    NextChannelHandler nh;
  1.6922 +    Channel* upChanPtr;
  1.6923 +    Tcl_ChannelType* upTypePtr;
  1.6924 +
  1.6925 +#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
  1.6926 +    /* [SF Tcl Bug 943274]
  1.6927 +     * For a non-blocking channel without blockmodeproc we keep track
  1.6928 +     * of actual input coming from the OS so that we can do a credible
  1.6929 +     * imitation of non-blocking behaviour.
  1.6930 +     */
  1.6931 +
  1.6932 +    if ((mask & TCL_READABLE) &&
  1.6933 +	(statePtr->flags & CHANNEL_NONBLOCKING) &&
  1.6934 +	(Tcl_ChannelBlockModeProc(chanPtr->typePtr) == NULL) &&
  1.6935 +	!(statePtr->flags & CHANNEL_TIMER_FEV)) {
  1.6936 +
  1.6937 +        statePtr->flags |= CHANNEL_HAS_MORE_DATA;
  1.6938 +    }
  1.6939 +#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
  1.6940 +
  1.6941 +    /*
  1.6942 +     * In contrast to the other API functions this procedure walks towards
  1.6943 +     * the top of a stack and not down from it.
  1.6944 +     *
  1.6945 +     * The channel calling this procedure is the one who generated the event,
  1.6946 +     * and thus does not take part in handling it. IOW, its HandlerProc is
  1.6947 +     * not called, instead we begin with the channel above it.
  1.6948 +     *
  1.6949 +     * This behaviour also allows the transformation channels to
  1.6950 +     * generate their own events and pass them upward.
  1.6951 +     */
  1.6952 +
  1.6953 +    while (mask && (chanPtr->upChanPtr != ((Channel*) NULL))) {
  1.6954 +	Tcl_DriverHandlerProc* upHandlerProc;
  1.6955 +
  1.6956 +        upChanPtr = chanPtr->upChanPtr;
  1.6957 +	upTypePtr = upChanPtr->typePtr;
  1.6958 +	upHandlerProc = Tcl_ChannelHandlerProc(upTypePtr);
  1.6959 +	if (upHandlerProc != NULL) {
  1.6960 +	    mask = (*upHandlerProc) (upChanPtr->instanceData, mask);
  1.6961 +	}
  1.6962 +
  1.6963 +	/* ELSE:
  1.6964 +	 * Ignore transformations which are unable to handle the event
  1.6965 +	 * coming from below. Assume that they don't change the mask and
  1.6966 +	 * pass it on.
  1.6967 +	 */
  1.6968 +
  1.6969 +	chanPtr = upChanPtr;
  1.6970 +    }
  1.6971 +
  1.6972 +    channel = (Tcl_Channel) chanPtr;
  1.6973 +
  1.6974 +    /*
  1.6975 +     * Here we have either reached the top of the stack or the mask is
  1.6976 +     * empty.  We break out of the procedure if it is the latter.
  1.6977 +     */
  1.6978 +
  1.6979 +    if (!mask) {
  1.6980 +        return;
  1.6981 +    }
  1.6982 +
  1.6983 +    /*
  1.6984 +     * We are now above the topmost channel in a stack and have events
  1.6985 +     * left. Now call the channel handlers as usual.
  1.6986 +     *
  1.6987 +     * Preserve the channel struct in case the script closes it.
  1.6988 +     */
  1.6989 +     
  1.6990 +    Tcl_Preserve((ClientData) channel);
  1.6991 +    Tcl_Preserve((ClientData) statePtr);
  1.6992 +
  1.6993 +    /*
  1.6994 +     * If we are flushing in the background, be sure to call FlushChannel
  1.6995 +     * for writable events.  Note that we have to discard the writable
  1.6996 +     * event so we don't call any write handlers before the flush is
  1.6997 +     * complete.
  1.6998 +     */
  1.6999 +
  1.7000 +    if ((statePtr->flags & BG_FLUSH_SCHEDULED) && (mask & TCL_WRITABLE)) {
  1.7001 +	FlushChannel(NULL, chanPtr, 1);
  1.7002 +	mask &= ~TCL_WRITABLE;
  1.7003 +    }
  1.7004 +
  1.7005 +    /*
  1.7006 +     * Add this invocation to the list of recursive invocations of
  1.7007 +     * ChannelHandlerEventProc.
  1.7008 +     */
  1.7009 +    
  1.7010 +    nh.nextHandlerPtr = (ChannelHandler *) NULL;
  1.7011 +    nh.nestedHandlerPtr = tsdPtr->nestedHandlerPtr;
  1.7012 +    tsdPtr->nestedHandlerPtr = &nh;
  1.7013 +
  1.7014 +    for (chPtr = statePtr->chPtr; chPtr != (ChannelHandler *) NULL; ) {
  1.7015 +	/*
  1.7016 +	 * If this channel handler is interested in any of the events that
  1.7017 +	 * have occurred on the channel, invoke its procedure.
  1.7018 +	 */
  1.7019 +
  1.7020 +	if ((chPtr->mask & mask) != 0) {
  1.7021 +	    nh.nextHandlerPtr = chPtr->nextPtr;
  1.7022 +	    (*(chPtr->proc))(chPtr->clientData, mask);
  1.7023 +	    chPtr = nh.nextHandlerPtr;
  1.7024 +	} else {
  1.7025 +	    chPtr = chPtr->nextPtr;
  1.7026 +	}
  1.7027 +    }
  1.7028 +
  1.7029 +    /*
  1.7030 +     * Update the notifier interest, since it may have changed after
  1.7031 +     * invoking event handlers. Skip that if the channel was deleted
  1.7032 +     * in the call to the channel handler.
  1.7033 +     */
  1.7034 +
  1.7035 +    if (chanPtr->typePtr != NULL) {
  1.7036 +        UpdateInterest(chanPtr);
  1.7037 +    }
  1.7038 +
  1.7039 +    Tcl_Release((ClientData) statePtr);
  1.7040 +    Tcl_Release((ClientData) channel);
  1.7041 +
  1.7042 +    tsdPtr->nestedHandlerPtr = nh.nestedHandlerPtr;
  1.7043 +}
  1.7044 +
  1.7045 +/*
  1.7046 + *----------------------------------------------------------------------
  1.7047 + *
  1.7048 + * UpdateInterest --
  1.7049 + *
  1.7050 + *	Arrange for the notifier to call us back at appropriate times
  1.7051 + *	based on the current state of the channel.
  1.7052 + *
  1.7053 + * Results:
  1.7054 + *	None.
  1.7055 + *
  1.7056 + * Side effects:
  1.7057 + *	May schedule a timer or driver handler.
  1.7058 + *
  1.7059 + *----------------------------------------------------------------------
  1.7060 + */
  1.7061 +
  1.7062 +static void
  1.7063 +UpdateInterest(chanPtr)
  1.7064 +    Channel *chanPtr;		/* Channel to update. */
  1.7065 +{
  1.7066 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.7067 +    int mask = statePtr->interestMask;
  1.7068 +
  1.7069 +    /*
  1.7070 +     * If there are flushed buffers waiting to be written, then
  1.7071 +     * we need to watch for the channel to become writable.
  1.7072 +     */
  1.7073 +
  1.7074 +    if (statePtr->flags & BG_FLUSH_SCHEDULED) {
  1.7075 +	mask |= TCL_WRITABLE;
  1.7076 +    }
  1.7077 +
  1.7078 +    /*
  1.7079 +     * If there is data in the input queue, and we aren't waiting for more
  1.7080 +     * data, then we need to schedule a timer so we don't block in the
  1.7081 +     * notifier.  Also, cancel the read interest so we don't get duplicate
  1.7082 +     * events.
  1.7083 +     */
  1.7084 +
  1.7085 +    if (mask & TCL_READABLE) {
  1.7086 +	if (!(statePtr->flags & CHANNEL_NEED_MORE_DATA)
  1.7087 +		&& (statePtr->inQueueHead != (ChannelBuffer *) NULL)
  1.7088 +		&& (statePtr->inQueueHead->nextRemoved <
  1.7089 +			statePtr->inQueueHead->nextAdded)) {
  1.7090 +	    mask &= ~TCL_READABLE;
  1.7091 +
  1.7092 +	    /*
  1.7093 +	     * Andreas Kupries, April 11, 2003
  1.7094 +	     *
  1.7095 +	     * Some operating systems (Solaris 2.6 and higher (but not
  1.7096 +	     * Solaris 2.5, go figure)) generate READABLE and
  1.7097 +	     * EXCEPTION events when select()'ing [*] on a plain file,
  1.7098 +	     * even if EOF was not yet reached. This is a problem in
  1.7099 +	     * the following situation:
  1.7100 +	     *
  1.7101 +	     * - An extension asks to get both READABLE and EXCEPTION
  1.7102 +	     *   events.
  1.7103 +	     * - It reads data into a buffer smaller than the buffer
  1.7104 +	     *   used by Tcl itself.
  1.7105 +	     * - It does not process all events in the event queue, but
  1.7106 +	     *   only only one, at least in some situations.
  1.7107 +	     *
  1.7108 +	     * In that case we can get into a situation where
  1.7109 +	     *
  1.7110 +	     * - Tcl drops READABLE here, because it has data in its own
  1.7111 +	     *   buffers waiting to be read by the extension.
  1.7112 +	     * - A READABLE event is syntesized via timer.
  1.7113 +	     * - The OS still reports the EXCEPTION condition on the file.
  1.7114 +	     * - And the extension gets the EXCPTION event first, and
  1.7115 +	     *   handles this as EOF.
  1.7116 +	     *
  1.7117 +	     * End result ==> Premature end of reading from a file.
  1.7118 +	     *
  1.7119 +	     * The concrete example is 'Expect', and its [expect]
  1.7120 +	     * command (and at the C-level, deep in the bowels of
  1.7121 +	     * Expect, 'exp_get_next_event'. See marker 'SunOS' for
  1.7122 +	     * commentary in that function too).
  1.7123 +	     *
  1.7124 +	     * [*] As the Tcl notifier does. See also for marker
  1.7125 +	     * 'SunOS' in file 'exp_event.c' of Expect.
  1.7126 +	     *
  1.7127 +	     * Our solution here is to drop the interest in the
  1.7128 +	     * EXCEPTION events too. This compiles on all platforms,
  1.7129 +	     * and also passes the testsuite on all of them.
  1.7130 +	     */
  1.7131 +
  1.7132 +	    mask &= ~TCL_EXCEPTION;
  1.7133 +
  1.7134 +	    if (!statePtr->timer) {
  1.7135 +		statePtr->timer = Tcl_CreateTimerHandler(0, ChannelTimerProc,
  1.7136 +			(ClientData) chanPtr);
  1.7137 +	    }
  1.7138 +	}
  1.7139 +    }
  1.7140 +    (chanPtr->typePtr->watchProc)(chanPtr->instanceData, mask);
  1.7141 +}
  1.7142 +
  1.7143 +/*
  1.7144 + *----------------------------------------------------------------------
  1.7145 + *
  1.7146 + * ChannelTimerProc --
  1.7147 + *
  1.7148 + *	Timer handler scheduled by UpdateInterest to monitor the
  1.7149 + *	channel buffers until they are empty.
  1.7150 + *
  1.7151 + * Results:
  1.7152 + *	None.
  1.7153 + *
  1.7154 + * Side effects:
  1.7155 + *	May invoke channel handlers.
  1.7156 + *
  1.7157 + *----------------------------------------------------------------------
  1.7158 + */
  1.7159 +
  1.7160 +static void
  1.7161 +ChannelTimerProc(clientData)
  1.7162 +    ClientData clientData;
  1.7163 +{
  1.7164 +    Channel *chanPtr = (Channel *) clientData;
  1.7165 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.7166 +
  1.7167 +    if (!(statePtr->flags & CHANNEL_NEED_MORE_DATA)
  1.7168 +	    && (statePtr->interestMask & TCL_READABLE)
  1.7169 +	    && (statePtr->inQueueHead != (ChannelBuffer *) NULL)
  1.7170 +	    && (statePtr->inQueueHead->nextRemoved <
  1.7171 +		    statePtr->inQueueHead->nextAdded)) {
  1.7172 +	/*
  1.7173 +	 * Restart the timer in case a channel handler reenters the
  1.7174 +	 * event loop before UpdateInterest gets called by Tcl_NotifyChannel.
  1.7175 +	 */
  1.7176 +
  1.7177 +	statePtr->timer = Tcl_CreateTimerHandler(0, ChannelTimerProc,
  1.7178 +		(ClientData) chanPtr);
  1.7179 +
  1.7180 +#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
  1.7181 +	/* Set the TIMER flag to notify the higher levels that the
  1.7182 +	 * driver might have no data for us. We do this only if we are
  1.7183 +	 * in non-blocking mode and the driver has no BlockModeProc
  1.7184 +	 * because only then we really don't know if the driver will
  1.7185 +	 * block or not. A similar test is done in "PeekAhead".
  1.7186 +	 */
  1.7187 +
  1.7188 +	if ((statePtr->flags & CHANNEL_NONBLOCKING) &&
  1.7189 +	    (Tcl_ChannelBlockModeProc(chanPtr->typePtr) == NULL)) {
  1.7190 +	    statePtr->flags |= CHANNEL_TIMER_FEV;
  1.7191 +	}
  1.7192 +#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
  1.7193 +
  1.7194 +	Tcl_Preserve((ClientData) statePtr);
  1.7195 +	Tcl_NotifyChannel((Tcl_Channel)chanPtr, TCL_READABLE);
  1.7196 +
  1.7197 +#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
  1.7198 +	statePtr->flags &= ~CHANNEL_TIMER_FEV; 
  1.7199 +#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
  1.7200 +
  1.7201 +	Tcl_Release((ClientData) statePtr);
  1.7202 +    } else {
  1.7203 +	statePtr->timer = NULL;
  1.7204 +	UpdateInterest(chanPtr);
  1.7205 +    }
  1.7206 +}
  1.7207 +
  1.7208 +/*
  1.7209 + *----------------------------------------------------------------------
  1.7210 + *
  1.7211 + * Tcl_CreateChannelHandler --
  1.7212 + *
  1.7213 + *	Arrange for a given procedure to be invoked whenever the
  1.7214 + *	channel indicated by the chanPtr arg becomes readable or
  1.7215 + *	writable.
  1.7216 + *
  1.7217 + * Results:
  1.7218 + *	None.
  1.7219 + *
  1.7220 + * Side effects:
  1.7221 + *	From now on, whenever the I/O channel given by chanPtr becomes
  1.7222 + *	ready in the way indicated by mask, proc will be invoked.
  1.7223 + *	See the manual entry for details on the calling sequence
  1.7224 + *	to proc.  If there is already an event handler for chan, proc
  1.7225 + *	and clientData, then the mask will be updated.
  1.7226 + *
  1.7227 + *----------------------------------------------------------------------
  1.7228 + */
  1.7229 +
  1.7230 +EXPORT_C void
  1.7231 +Tcl_CreateChannelHandler(chan, mask, proc, clientData)
  1.7232 +    Tcl_Channel chan;		/* The channel to create the handler for. */
  1.7233 +    int mask;			/* OR'ed combination of TCL_READABLE,
  1.7234 +				 * TCL_WRITABLE, and TCL_EXCEPTION:
  1.7235 +				 * indicates conditions under which
  1.7236 +				 * proc should be called. Use 0 to
  1.7237 +                                 * disable a registered handler. */
  1.7238 +    Tcl_ChannelProc *proc;	/* Procedure to call for each
  1.7239 +				 * selected event. */
  1.7240 +    ClientData clientData;	/* Arbitrary data to pass to proc. */
  1.7241 +{
  1.7242 +    ChannelHandler *chPtr;
  1.7243 +    Channel *chanPtr = (Channel *) chan;
  1.7244 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.7245 +
  1.7246 +    /*
  1.7247 +     * Check whether this channel handler is not already registered. If
  1.7248 +     * it is not, create a new record, else reuse existing record (smash
  1.7249 +     * current values).
  1.7250 +     */
  1.7251 +
  1.7252 +    for (chPtr = statePtr->chPtr;
  1.7253 +	 chPtr != (ChannelHandler *) NULL;
  1.7254 +	 chPtr = chPtr->nextPtr) {
  1.7255 +        if ((chPtr->chanPtr == chanPtr) && (chPtr->proc == proc) &&
  1.7256 +                (chPtr->clientData == clientData)) {
  1.7257 +            break;
  1.7258 +        }
  1.7259 +    }
  1.7260 +    if (chPtr == (ChannelHandler *) NULL) {
  1.7261 +        chPtr = (ChannelHandler *) ckalloc((unsigned) sizeof(ChannelHandler));
  1.7262 +        chPtr->mask = 0;
  1.7263 +        chPtr->proc = proc;
  1.7264 +        chPtr->clientData = clientData;
  1.7265 +        chPtr->chanPtr = chanPtr;
  1.7266 +        chPtr->nextPtr = statePtr->chPtr;
  1.7267 +        statePtr->chPtr = chPtr;
  1.7268 +    }
  1.7269 +
  1.7270 +    /*
  1.7271 +     * The remainder of the initialization below is done regardless of
  1.7272 +     * whether or not this is a new record or a modification of an old
  1.7273 +     * one.
  1.7274 +     */
  1.7275 +
  1.7276 +    chPtr->mask = mask;
  1.7277 +
  1.7278 +    /*
  1.7279 +     * Recompute the interest mask for the channel - this call may actually
  1.7280 +     * be disabling an existing handler.
  1.7281 +     */
  1.7282 +    
  1.7283 +    statePtr->interestMask = 0;
  1.7284 +    for (chPtr = statePtr->chPtr;
  1.7285 +	 chPtr != (ChannelHandler *) NULL;
  1.7286 +	 chPtr = chPtr->nextPtr) {
  1.7287 +	statePtr->interestMask |= chPtr->mask;
  1.7288 +    }
  1.7289 +
  1.7290 +    UpdateInterest(statePtr->topChanPtr);
  1.7291 +}
  1.7292 +
  1.7293 +/*
  1.7294 + *----------------------------------------------------------------------
  1.7295 + *
  1.7296 + * Tcl_DeleteChannelHandler --
  1.7297 + *
  1.7298 + *	Cancel a previously arranged callback arrangement for an IO
  1.7299 + *	channel.
  1.7300 + *
  1.7301 + * Results:
  1.7302 + *	None.
  1.7303 + *
  1.7304 + * Side effects:
  1.7305 + *	If a callback was previously registered for this chan, proc and
  1.7306 + *	 clientData , it is removed and the callback will no longer be called
  1.7307 + *	when the channel becomes ready for IO.
  1.7308 + *
  1.7309 + *----------------------------------------------------------------------
  1.7310 + */
  1.7311 +
  1.7312 +EXPORT_C void
  1.7313 +Tcl_DeleteChannelHandler(chan, proc, clientData)
  1.7314 +    Tcl_Channel chan;		/* The channel for which to remove the
  1.7315 +                                 * callback. */
  1.7316 +    Tcl_ChannelProc *proc;	/* The procedure in the callback to delete. */
  1.7317 +    ClientData clientData;	/* The client data in the callback
  1.7318 +                                 * to delete. */
  1.7319 +    
  1.7320 +{
  1.7321 +    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
  1.7322 +    ChannelHandler *chPtr, *prevChPtr;
  1.7323 +    Channel *chanPtr = (Channel *) chan;
  1.7324 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.7325 +    NextChannelHandler *nhPtr;
  1.7326 +
  1.7327 +    /*
  1.7328 +     * Find the entry and the previous one in the list.
  1.7329 +     */
  1.7330 +
  1.7331 +    for (prevChPtr = (ChannelHandler *) NULL, chPtr = statePtr->chPtr;
  1.7332 +	 chPtr != (ChannelHandler *) NULL;
  1.7333 +	 chPtr = chPtr->nextPtr) {
  1.7334 +        if ((chPtr->chanPtr == chanPtr) && (chPtr->clientData == clientData)
  1.7335 +                && (chPtr->proc == proc)) {
  1.7336 +            break;
  1.7337 +        }
  1.7338 +        prevChPtr = chPtr;
  1.7339 +    }
  1.7340 +
  1.7341 +    /*
  1.7342 +     * If not found, return without doing anything.
  1.7343 +     */
  1.7344 +
  1.7345 +    if (chPtr == (ChannelHandler *) NULL) {
  1.7346 +        return;
  1.7347 +    }
  1.7348 +
  1.7349 +    /*
  1.7350 +     * If ChannelHandlerEventProc is about to process this handler, tell it to
  1.7351 +     * process the next one instead - we are going to delete *this* one.
  1.7352 +     */
  1.7353 +
  1.7354 +    for (nhPtr = tsdPtr->nestedHandlerPtr;
  1.7355 +	 nhPtr != (NextChannelHandler *) NULL;
  1.7356 +	 nhPtr = nhPtr->nestedHandlerPtr) {
  1.7357 +        if (nhPtr->nextHandlerPtr == chPtr) {
  1.7358 +            nhPtr->nextHandlerPtr = chPtr->nextPtr;
  1.7359 +        }
  1.7360 +    }
  1.7361 +
  1.7362 +    /*
  1.7363 +     * Splice it out of the list of channel handlers.
  1.7364 +     */
  1.7365 +    
  1.7366 +    if (prevChPtr == (ChannelHandler *) NULL) {
  1.7367 +        statePtr->chPtr = chPtr->nextPtr;
  1.7368 +    } else {
  1.7369 +        prevChPtr->nextPtr = chPtr->nextPtr;
  1.7370 +    }
  1.7371 +    ckfree((char *) chPtr);
  1.7372 +
  1.7373 +    /*
  1.7374 +     * Recompute the interest list for the channel, so that infinite loops
  1.7375 +     * will not result if Tcl_DeleteChannelHandler is called inside an
  1.7376 +     * event.
  1.7377 +     */
  1.7378 +
  1.7379 +    statePtr->interestMask = 0;
  1.7380 +    for (chPtr = statePtr->chPtr;
  1.7381 +	 chPtr != (ChannelHandler *) NULL;
  1.7382 +	 chPtr = chPtr->nextPtr) {
  1.7383 +        statePtr->interestMask |= chPtr->mask;
  1.7384 +    }
  1.7385 +
  1.7386 +    UpdateInterest(statePtr->topChanPtr);
  1.7387 +}
  1.7388 +
  1.7389 +/*
  1.7390 + *----------------------------------------------------------------------
  1.7391 + *
  1.7392 + * DeleteScriptRecord --
  1.7393 + *
  1.7394 + *	Delete a script record for this combination of channel, interp
  1.7395 + *	and mask.
  1.7396 + *
  1.7397 + * Results:
  1.7398 + *	None.
  1.7399 + *
  1.7400 + * Side effects:
  1.7401 + *	Deletes a script record and cancels a channel event handler.
  1.7402 + *
  1.7403 + *----------------------------------------------------------------------
  1.7404 + */
  1.7405 +
  1.7406 +static void
  1.7407 +DeleteScriptRecord(interp, chanPtr, mask)
  1.7408 +    Tcl_Interp *interp;		/* Interpreter in which script was to be
  1.7409 +                                 * executed. */
  1.7410 +    Channel *chanPtr;		/* The channel for which to delete the
  1.7411 +                                 * script record (if any). */
  1.7412 +    int mask;			/* Events in mask must exactly match mask
  1.7413 +                                 * of script to delete. */
  1.7414 +{
  1.7415 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.7416 +    EventScriptRecord *esPtr, *prevEsPtr;
  1.7417 +
  1.7418 +    for (esPtr = statePtr->scriptRecordPtr,
  1.7419 +             prevEsPtr = (EventScriptRecord *) NULL;
  1.7420 +	 esPtr != (EventScriptRecord *) NULL;
  1.7421 +	 prevEsPtr = esPtr, esPtr = esPtr->nextPtr) {
  1.7422 +        if ((esPtr->interp == interp) && (esPtr->mask == mask)) {
  1.7423 +            if (esPtr == statePtr->scriptRecordPtr) {
  1.7424 +                statePtr->scriptRecordPtr = esPtr->nextPtr;
  1.7425 +            } else {
  1.7426 +                prevEsPtr->nextPtr = esPtr->nextPtr;
  1.7427 +            }
  1.7428 +
  1.7429 +            Tcl_DeleteChannelHandler((Tcl_Channel) chanPtr,
  1.7430 +                    TclChannelEventScriptInvoker, (ClientData) esPtr);
  1.7431 +            
  1.7432 +	    Tcl_DecrRefCount(esPtr->scriptPtr);
  1.7433 +            ckfree((char *) esPtr);
  1.7434 +
  1.7435 +            break;
  1.7436 +        }
  1.7437 +    }
  1.7438 +}
  1.7439 +
  1.7440 +/*
  1.7441 + *----------------------------------------------------------------------
  1.7442 + *
  1.7443 + * CreateScriptRecord --
  1.7444 + *
  1.7445 + *	Creates a record to store a script to be executed when a specific
  1.7446 + *	event fires on a specific channel.
  1.7447 + *
  1.7448 + * Results:
  1.7449 + *	None.
  1.7450 + *
  1.7451 + * Side effects:
  1.7452 + *	Causes the script to be stored for later execution.
  1.7453 + *
  1.7454 + *----------------------------------------------------------------------
  1.7455 + */
  1.7456 +
  1.7457 +static void
  1.7458 +CreateScriptRecord(interp, chanPtr, mask, scriptPtr)
  1.7459 +    Tcl_Interp *interp;			/* Interpreter in which to execute
  1.7460 +                                         * the stored script. */
  1.7461 +    Channel *chanPtr;			/* Channel for which script is to
  1.7462 +                                         * be stored. */
  1.7463 +    int mask;				/* Set of events for which script
  1.7464 +                                         * will be invoked. */
  1.7465 +    Tcl_Obj *scriptPtr;			/* Pointer to script object. */
  1.7466 +{
  1.7467 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.7468 +    EventScriptRecord *esPtr;
  1.7469 +
  1.7470 +    for (esPtr = statePtr->scriptRecordPtr;
  1.7471 +	 esPtr != (EventScriptRecord *) NULL;
  1.7472 +	 esPtr = esPtr->nextPtr) {
  1.7473 +        if ((esPtr->interp == interp) && (esPtr->mask == mask)) {
  1.7474 +	    Tcl_DecrRefCount(esPtr->scriptPtr);
  1.7475 +	    esPtr->scriptPtr = (Tcl_Obj *) NULL;
  1.7476 +            break;
  1.7477 +        }
  1.7478 +    }
  1.7479 +    if (esPtr == (EventScriptRecord *) NULL) {
  1.7480 +        esPtr = (EventScriptRecord *) ckalloc((unsigned)
  1.7481 +                sizeof(EventScriptRecord));
  1.7482 +        Tcl_CreateChannelHandler((Tcl_Channel) chanPtr, mask,
  1.7483 +                TclChannelEventScriptInvoker, (ClientData) esPtr);
  1.7484 +        esPtr->nextPtr = statePtr->scriptRecordPtr;
  1.7485 +        statePtr->scriptRecordPtr = esPtr;
  1.7486 +    }
  1.7487 +    esPtr->chanPtr = chanPtr;
  1.7488 +    esPtr->interp = interp;
  1.7489 +    esPtr->mask = mask;
  1.7490 +    Tcl_IncrRefCount(scriptPtr);
  1.7491 +    esPtr->scriptPtr = scriptPtr;
  1.7492 +}
  1.7493 +
  1.7494 +/*
  1.7495 + *----------------------------------------------------------------------
  1.7496 + *
  1.7497 + * TclChannelEventScriptInvoker --
  1.7498 + *
  1.7499 + *	Invokes a script scheduled by "fileevent" for when the channel
  1.7500 + *	becomes ready for IO. This function is invoked by the channel
  1.7501 + *	handler which was created by the Tcl "fileevent" command.
  1.7502 + *
  1.7503 + * Results:
  1.7504 + *	None.
  1.7505 + *
  1.7506 + * Side effects:
  1.7507 + *	Whatever the script does.
  1.7508 + *
  1.7509 + *----------------------------------------------------------------------
  1.7510 + */
  1.7511 +
  1.7512 +void
  1.7513 +TclChannelEventScriptInvoker(clientData, mask)
  1.7514 +    ClientData clientData;	/* The script+interp record. */
  1.7515 +    int mask;			/* Not used. */
  1.7516 +{
  1.7517 +    Tcl_Interp *interp;		/* Interpreter in which to eval the script. */
  1.7518 +    Channel *chanPtr;		/* The channel for which this handler is
  1.7519 +                                 * registered. */
  1.7520 +    EventScriptRecord *esPtr;	/* The event script + interpreter to eval it
  1.7521 +                                 * in. */
  1.7522 +    int result;			/* Result of call to eval script. */
  1.7523 +
  1.7524 +    esPtr	= (EventScriptRecord *) clientData;
  1.7525 +    chanPtr	= esPtr->chanPtr;
  1.7526 +    mask	= esPtr->mask;
  1.7527 +    interp	= esPtr->interp;
  1.7528 +
  1.7529 +    /*
  1.7530 +     * We must preserve the interpreter so we can report errors on it
  1.7531 +     * later.  Note that we do not need to preserve the channel because
  1.7532 +     * that is done by Tcl_NotifyChannel before calling channel handlers.
  1.7533 +     */
  1.7534 +    
  1.7535 +    Tcl_Preserve((ClientData) interp);
  1.7536 +    result = Tcl_EvalObjEx(interp, esPtr->scriptPtr, TCL_EVAL_GLOBAL);
  1.7537 +
  1.7538 +    /*
  1.7539 +     * On error, cause a background error and remove the channel handler
  1.7540 +     * and the script record.
  1.7541 +     *
  1.7542 +     * NOTE: Must delete channel handler before causing the background error
  1.7543 +     * because the background error may want to reinstall the handler.
  1.7544 +     */
  1.7545 +    
  1.7546 +    if (result != TCL_OK) {
  1.7547 +	if (chanPtr->typePtr != NULL) {
  1.7548 +	    DeleteScriptRecord(interp, chanPtr, mask);
  1.7549 +	}
  1.7550 +        Tcl_BackgroundError(interp);
  1.7551 +    }
  1.7552 +    Tcl_Release((ClientData) interp);
  1.7553 +}
  1.7554 +
  1.7555 +/*
  1.7556 + *----------------------------------------------------------------------
  1.7557 + *
  1.7558 + * Tcl_FileEventObjCmd --
  1.7559 + *
  1.7560 + *	This procedure implements the "fileevent" Tcl command. See the
  1.7561 + *	user documentation for details on what it does. This command is
  1.7562 + *	based on the Tk command "fileevent" which in turn is based on work
  1.7563 + *	contributed by Mark Diekhans.
  1.7564 + *
  1.7565 + * Results:
  1.7566 + *	A standard Tcl result.
  1.7567 + *
  1.7568 + * Side effects:
  1.7569 + *	May create a channel handler for the specified channel.
  1.7570 + *
  1.7571 + *----------------------------------------------------------------------
  1.7572 + */
  1.7573 +
  1.7574 +	/* ARGSUSED */
  1.7575 +int
  1.7576 +Tcl_FileEventObjCmd(clientData, interp, objc, objv)
  1.7577 +    ClientData clientData;		/* Not used. */
  1.7578 +    Tcl_Interp *interp;			/* Interpreter in which the channel
  1.7579 +                                         * for which to create the handler
  1.7580 +                                         * is found. */
  1.7581 +    int objc;				/* Number of arguments. */
  1.7582 +    Tcl_Obj *CONST objv[];		/* Argument objects. */
  1.7583 +{
  1.7584 +    Channel *chanPtr;			/* The channel to create
  1.7585 +                                         * the handler for. */
  1.7586 +    ChannelState *statePtr;		/* state info for channel */
  1.7587 +    Tcl_Channel chan;			/* The opaque type for the channel. */
  1.7588 +    char *chanName;
  1.7589 +    int modeIndex;			/* Index of mode argument. */
  1.7590 +    int mask;
  1.7591 +    static CONST char *modeOptions[] = {"readable", "writable", NULL};
  1.7592 +    static int maskArray[] = {TCL_READABLE, TCL_WRITABLE};
  1.7593 +
  1.7594 +    if ((objc != 3) && (objc != 4)) {
  1.7595 +	Tcl_WrongNumArgs(interp, 1, objv, "channelId event ?script?");
  1.7596 +	return TCL_ERROR;
  1.7597 +    }
  1.7598 +    if (Tcl_GetIndexFromObj(interp, objv[2], modeOptions, "event name", 0,
  1.7599 +	    &modeIndex) != TCL_OK) {
  1.7600 +	return TCL_ERROR;
  1.7601 +    }
  1.7602 +    mask = maskArray[modeIndex];
  1.7603 +
  1.7604 +    chanName = Tcl_GetString(objv[1]);
  1.7605 +    chan = Tcl_GetChannel(interp, chanName, NULL);
  1.7606 +    if (chan == (Tcl_Channel) NULL) {
  1.7607 +	return TCL_ERROR;
  1.7608 +    }
  1.7609 +    chanPtr  = (Channel *) chan;
  1.7610 +    statePtr = chanPtr->state;
  1.7611 +    if ((statePtr->flags & mask) == 0) {
  1.7612 +        Tcl_AppendResult(interp, "channel is not ",
  1.7613 +                (mask == TCL_READABLE) ? "readable" : "writable",
  1.7614 +                (char *) NULL);
  1.7615 +        return TCL_ERROR;
  1.7616 +    }
  1.7617 +    
  1.7618 +    /*
  1.7619 +     * If we are supposed to return the script, do so.
  1.7620 +     */
  1.7621 +
  1.7622 +    if (objc == 3) {
  1.7623 +	EventScriptRecord *esPtr;
  1.7624 +	for (esPtr = statePtr->scriptRecordPtr;
  1.7625 +             esPtr != (EventScriptRecord *) NULL;
  1.7626 +             esPtr = esPtr->nextPtr) {
  1.7627 +	    if ((esPtr->interp == interp) && (esPtr->mask == mask)) {
  1.7628 +		Tcl_SetObjResult(interp, esPtr->scriptPtr);
  1.7629 +		break;
  1.7630 +	    }
  1.7631 +	}
  1.7632 +        return TCL_OK;
  1.7633 +    }
  1.7634 +
  1.7635 +    /*
  1.7636 +     * If we are supposed to delete a stored script, do so.
  1.7637 +     */
  1.7638 +
  1.7639 +    if (*(Tcl_GetString(objv[3])) == '\0') {
  1.7640 +        DeleteScriptRecord(interp, chanPtr, mask);
  1.7641 +        return TCL_OK;
  1.7642 +    }
  1.7643 +
  1.7644 +    /*
  1.7645 +     * Make the script record that will link between the event and the
  1.7646 +     * script to invoke. This also creates a channel event handler which
  1.7647 +     * will evaluate the script in the supplied interpreter.
  1.7648 +     */
  1.7649 +
  1.7650 +    CreateScriptRecord(interp, chanPtr, mask, objv[3]);
  1.7651 +    
  1.7652 +    return TCL_OK;
  1.7653 +}
  1.7654 +
  1.7655 +/*
  1.7656 + *----------------------------------------------------------------------
  1.7657 + *
  1.7658 + * TclCopyChannel --
  1.7659 + *
  1.7660 + *	This routine copies data from one channel to another, either
  1.7661 + *	synchronously or asynchronously.  If a command script is
  1.7662 + *	supplied, the operation runs in the background.  The script
  1.7663 + *	is invoked when the copy completes.  Otherwise the function
  1.7664 + *	waits until the copy is completed before returning.
  1.7665 + *
  1.7666 + * Results:
  1.7667 + *	A standard Tcl result.
  1.7668 + *
  1.7669 + * Side effects:
  1.7670 + *	May schedule a background copy operation that causes both
  1.7671 + *	channels to be marked busy.
  1.7672 + *
  1.7673 + *----------------------------------------------------------------------
  1.7674 + */
  1.7675 +
  1.7676 +int
  1.7677 +TclCopyChannel(interp, inChan, outChan, toRead, cmdPtr)
  1.7678 +    Tcl_Interp *interp;		/* Current interpreter. */
  1.7679 +    Tcl_Channel inChan;		/* Channel to read from. */
  1.7680 +    Tcl_Channel outChan;	/* Channel to write to. */
  1.7681 +    int toRead;			/* Amount of data to copy, or -1 for all. */
  1.7682 +    Tcl_Obj *cmdPtr;		/* Pointer to script to execute or NULL. */
  1.7683 +{
  1.7684 +    Channel *inPtr = (Channel *) inChan;
  1.7685 +    Channel *outPtr = (Channel *) outChan;
  1.7686 +    ChannelState *inStatePtr, *outStatePtr;
  1.7687 +    int readFlags, writeFlags;
  1.7688 +    CopyState *csPtr;
  1.7689 +    int nonBlocking = (cmdPtr) ? CHANNEL_NONBLOCKING : 0;
  1.7690 +
  1.7691 +    inStatePtr	= inPtr->state;
  1.7692 +    outStatePtr	= outPtr->state;
  1.7693 +
  1.7694 +    if (inStatePtr->csPtr) {
  1.7695 +	if (interp) {
  1.7696 +	    Tcl_AppendStringsToObj(Tcl_GetObjResult(interp), "channel \"",
  1.7697 +		    Tcl_GetChannelName(inChan), "\" is busy", NULL);
  1.7698 +	}
  1.7699 +	return TCL_ERROR;
  1.7700 +    }
  1.7701 +    if (outStatePtr->csPtr) {
  1.7702 +	if (interp) {
  1.7703 +	    Tcl_AppendStringsToObj(Tcl_GetObjResult(interp), "channel \"",
  1.7704 +		    Tcl_GetChannelName(outChan), "\" is busy", NULL);
  1.7705 +	}
  1.7706 +	return TCL_ERROR;
  1.7707 +    }
  1.7708 +
  1.7709 +    readFlags	= inStatePtr->flags;
  1.7710 +    writeFlags	= outStatePtr->flags;
  1.7711 +
  1.7712 +    /*
  1.7713 +     * Set up the blocking mode appropriately.  Background copies need
  1.7714 +     * non-blocking channels.  Foreground copies need blocking channels.
  1.7715 +     * If there is an error, restore the old blocking mode.
  1.7716 +     */
  1.7717 +
  1.7718 +    if (nonBlocking != (readFlags & CHANNEL_NONBLOCKING)) {
  1.7719 +	if (SetBlockMode(interp, inPtr,
  1.7720 +		nonBlocking ? TCL_MODE_NONBLOCKING : TCL_MODE_BLOCKING)
  1.7721 +		!= TCL_OK) {
  1.7722 +	    return TCL_ERROR;
  1.7723 +	}
  1.7724 +    }	    
  1.7725 +    if (inPtr != outPtr) {
  1.7726 +	if (nonBlocking != (writeFlags & CHANNEL_NONBLOCKING)) {
  1.7727 +	    if (SetBlockMode(NULL, outPtr,
  1.7728 +		    nonBlocking ? TCL_MODE_NONBLOCKING : TCL_MODE_BLOCKING)
  1.7729 +		    != TCL_OK) {
  1.7730 +		if (nonBlocking != (readFlags & CHANNEL_NONBLOCKING)) {
  1.7731 +		    SetBlockMode(NULL, inPtr,
  1.7732 +			    (readFlags & CHANNEL_NONBLOCKING)
  1.7733 +			    ? TCL_MODE_NONBLOCKING : TCL_MODE_BLOCKING);
  1.7734 +		    return TCL_ERROR;
  1.7735 +		}
  1.7736 +	    }
  1.7737 +	}
  1.7738 +    }
  1.7739 +
  1.7740 +    /*
  1.7741 +     * Make sure the output side is unbuffered.
  1.7742 +     */
  1.7743 +
  1.7744 +    outStatePtr->flags = (outStatePtr->flags & ~(CHANNEL_LINEBUFFERED))
  1.7745 +	| CHANNEL_UNBUFFERED;
  1.7746 +
  1.7747 +    /*
  1.7748 +     * Allocate a new CopyState to maintain info about the current copy in
  1.7749 +     * progress.  This structure will be deallocated when the copy is
  1.7750 +     * completed.
  1.7751 +     */
  1.7752 +
  1.7753 +    csPtr = (CopyState*) ckalloc(sizeof(CopyState) + inStatePtr->bufSize);
  1.7754 +    csPtr->bufSize    = inStatePtr->bufSize;
  1.7755 +    csPtr->readPtr    = inPtr;
  1.7756 +    csPtr->writePtr   = outPtr;
  1.7757 +    csPtr->readFlags  = readFlags;
  1.7758 +    csPtr->writeFlags = writeFlags;
  1.7759 +    csPtr->toRead     = toRead;
  1.7760 +    csPtr->total      = 0;
  1.7761 +    csPtr->interp     = interp;
  1.7762 +    if (cmdPtr) {
  1.7763 +	Tcl_IncrRefCount(cmdPtr);
  1.7764 +    }
  1.7765 +    csPtr->cmdPtr = cmdPtr;
  1.7766 +    inStatePtr->csPtr = csPtr;
  1.7767 +    outStatePtr->csPtr = csPtr;
  1.7768 +
  1.7769 +    /*
  1.7770 +     * Start copying data between the channels.
  1.7771 +     */
  1.7772 +
  1.7773 +    return CopyData(csPtr, 0);
  1.7774 +}
  1.7775 +
  1.7776 +/*
  1.7777 + *----------------------------------------------------------------------
  1.7778 + *
  1.7779 + * CopyData --
  1.7780 + *
  1.7781 + *	This function implements the lowest level of the copying
  1.7782 + *	mechanism for TclCopyChannel.
  1.7783 + *
  1.7784 + * Results:
  1.7785 + *	Returns TCL_OK on success, else TCL_ERROR.
  1.7786 + *
  1.7787 + * Side effects:
  1.7788 + *	Moves data between channels, may create channel handlers.
  1.7789 + *
  1.7790 + *----------------------------------------------------------------------
  1.7791 + */
  1.7792 +
  1.7793 +static int
  1.7794 +CopyData(csPtr, mask)
  1.7795 +    CopyState *csPtr;		/* State of copy operation. */
  1.7796 +    int mask;			/* Current channel event flags. */
  1.7797 +{
  1.7798 +    Tcl_Interp *interp;
  1.7799 +    Tcl_Obj *cmdPtr, *errObj = NULL, *bufObj = NULL;
  1.7800 +    Tcl_Channel inChan, outChan;
  1.7801 +    ChannelState *inStatePtr, *outStatePtr;
  1.7802 +    int result = TCL_OK, size, total, sizeb;
  1.7803 +    char* buffer;
  1.7804 +
  1.7805 +    int inBinary, outBinary, sameEncoding; /* Encoding control */
  1.7806 +    int underflow;	/* input underflow */
  1.7807 +
  1.7808 +    inChan	= (Tcl_Channel) csPtr->readPtr;
  1.7809 +    outChan	= (Tcl_Channel) csPtr->writePtr;
  1.7810 +    inStatePtr	= csPtr->readPtr->state;
  1.7811 +    outStatePtr	= csPtr->writePtr->state;
  1.7812 +    interp	= csPtr->interp;
  1.7813 +    cmdPtr	= csPtr->cmdPtr;
  1.7814 +
  1.7815 +    /*
  1.7816 +     * Copy the data the slow way, using the translation mechanism.
  1.7817 +     *
  1.7818 +     * Note: We have make sure that we use the topmost channel in a stack
  1.7819 +     * for the copying. The caller uses Tcl_GetChannel to access it, and
  1.7820 +     * thus gets the bottom of the stack.
  1.7821 +     */
  1.7822 +
  1.7823 +    inBinary     = (inStatePtr->encoding  == NULL);
  1.7824 +    outBinary    = (outStatePtr->encoding == NULL);
  1.7825 +    sameEncoding = (inStatePtr->encoding  == outStatePtr->encoding);
  1.7826 +
  1.7827 +    if (!(inBinary || sameEncoding)) {
  1.7828 +        bufObj = Tcl_NewObj ();
  1.7829 +	Tcl_IncrRefCount (bufObj);
  1.7830 +    }
  1.7831 +
  1.7832 +    while (csPtr->toRead != 0) {
  1.7833 +	/*
  1.7834 +	 * Check for unreported background errors.
  1.7835 +	 */
  1.7836 +
  1.7837 +	if (inStatePtr->unreportedError != 0) {
  1.7838 +	    Tcl_SetErrno(inStatePtr->unreportedError);
  1.7839 +	    inStatePtr->unreportedError = 0;
  1.7840 +	    goto readError;
  1.7841 +	}
  1.7842 +	if (outStatePtr->unreportedError != 0) {
  1.7843 +	    Tcl_SetErrno(outStatePtr->unreportedError);
  1.7844 +	    outStatePtr->unreportedError = 0;
  1.7845 +	    goto writeError;
  1.7846 +	}
  1.7847 +	
  1.7848 +	/*
  1.7849 +	 * Read up to bufSize bytes.
  1.7850 +	 */
  1.7851 +
  1.7852 +	if ((csPtr->toRead == -1) || (csPtr->toRead > csPtr->bufSize)) {
  1.7853 +	    sizeb = csPtr->bufSize;
  1.7854 +	} else {
  1.7855 +	    sizeb = csPtr->toRead;
  1.7856 +	}
  1.7857 +
  1.7858 +	if (inBinary || sameEncoding) {
  1.7859 +	    size = DoRead(inStatePtr->topChanPtr, csPtr->buffer, sizeb);
  1.7860 +	} else {
  1.7861 +	    size = DoReadChars(inStatePtr->topChanPtr, bufObj, sizeb, 0 /* No append */);
  1.7862 +	}
  1.7863 +	underflow = (size >= 0) && (size < sizeb);	/* input underflow */
  1.7864 +
  1.7865 +	if (size < 0) {
  1.7866 +	    readError:
  1.7867 +	    errObj = Tcl_NewObj();
  1.7868 +	    Tcl_AppendStringsToObj(errObj, "error reading \"",
  1.7869 +		    Tcl_GetChannelName(inChan), "\": ",
  1.7870 +		    Tcl_PosixError(interp), (char *) NULL);
  1.7871 +	    break;
  1.7872 +	} else if (underflow) {
  1.7873 +	    /*
  1.7874 +	     * We had an underflow on the read side.  If we are at EOF,
  1.7875 +	     * then the copying is done, otherwise set up a channel
  1.7876 +	     * handler to detect when the channel becomes readable again.
  1.7877 +	     */
  1.7878 +	    
  1.7879 +	    if ((size == 0) && Tcl_Eof(inChan)) {
  1.7880 +		break;
  1.7881 +	    }
  1.7882 +	    if (! Tcl_Eof(inChan) && !(mask & TCL_READABLE)) {
  1.7883 +		if (mask & TCL_WRITABLE) {
  1.7884 +		    Tcl_DeleteChannelHandler(outChan, CopyEventProc,
  1.7885 +			    (ClientData) csPtr);
  1.7886 +		}
  1.7887 +		Tcl_CreateChannelHandler(inChan, TCL_READABLE,
  1.7888 +			CopyEventProc, (ClientData) csPtr);
  1.7889 +	    }
  1.7890 +	    if (size == 0) {
  1.7891 +	        if (bufObj != (Tcl_Obj*) NULL) {
  1.7892 +		    Tcl_DecrRefCount (bufObj);
  1.7893 +		    bufObj = (Tcl_Obj*) NULL;
  1.7894 +		}
  1.7895 +		return TCL_OK;
  1.7896 +	    }
  1.7897 +	}
  1.7898 +
  1.7899 +	/*
  1.7900 +	 * Now write the buffer out.
  1.7901 +	 */
  1.7902 +
  1.7903 +	if (inBinary || sameEncoding) {
  1.7904 +	    buffer = csPtr->buffer;
  1.7905 +	    sizeb = size;
  1.7906 +	} else {
  1.7907 +	    buffer = Tcl_GetStringFromObj (bufObj, &sizeb);
  1.7908 +	}
  1.7909 +
  1.7910 +	if (outBinary || sameEncoding) {
  1.7911 +	    sizeb = DoWrite(outStatePtr->topChanPtr, buffer, sizeb);
  1.7912 +	} else {
  1.7913 +	    sizeb = DoWriteChars(outStatePtr->topChanPtr, buffer, sizeb);
  1.7914 +	}
  1.7915 +
  1.7916 +	if (inBinary || sameEncoding) {
  1.7917 +	    /* Both read and write counted bytes */
  1.7918 +	    size = sizeb;
  1.7919 +	} /* else : Read counted characters, write counted bytes, i.e. size != sizeb */
  1.7920 +
  1.7921 +	if (sizeb < 0) {
  1.7922 +	    writeError:
  1.7923 +	    errObj = Tcl_NewObj();
  1.7924 +	    Tcl_AppendStringsToObj(errObj, "error writing \"",
  1.7925 +		    Tcl_GetChannelName(outChan), "\": ",
  1.7926 +		    Tcl_PosixError(interp), (char *) NULL);
  1.7927 +	    break;
  1.7928 +	}
  1.7929 +
  1.7930 +	/*
  1.7931 +	 * Update the current byte count.  Do it now so the count is
  1.7932 +	 * valid before a return or break takes us out of the loop.
  1.7933 +	 * The invariant at the top of the loop should be that 
  1.7934 +	 * csPtr->toRead holds the number of bytes left to copy.
  1.7935 +	 */
  1.7936 +
  1.7937 +	if (csPtr->toRead != -1) {
  1.7938 +	    csPtr->toRead -= size;
  1.7939 +	}
  1.7940 +	csPtr->total += size;
  1.7941 +
  1.7942 +	/*
  1.7943 +	 * Break loop if EOF && (size>0)
  1.7944 +	 */
  1.7945 +
  1.7946 +        if (Tcl_Eof(inChan)) {
  1.7947 +            break;
  1.7948 +        }
  1.7949 +
  1.7950 +	/*
  1.7951 +	 * Check to see if the write is happening in the background.  If so,
  1.7952 +	 * stop copying and wait for the channel to become writable again.
  1.7953 +	 * After input underflow we already installed a readable handler
  1.7954 +	 * therefore we don't need a writable handler.
  1.7955 +	 */
  1.7956 +
  1.7957 +	if ( ! underflow && (outStatePtr->flags & BG_FLUSH_SCHEDULED) ) {
  1.7958 +	    if (!(mask & TCL_WRITABLE)) {
  1.7959 +		if (mask & TCL_READABLE) {
  1.7960 +		    Tcl_DeleteChannelHandler(inChan, CopyEventProc,
  1.7961 +			    (ClientData) csPtr);
  1.7962 +		}
  1.7963 +		Tcl_CreateChannelHandler(outChan, TCL_WRITABLE,
  1.7964 +			CopyEventProc, (ClientData) csPtr);
  1.7965 +	    }
  1.7966 +	    if (bufObj != (Tcl_Obj*) NULL) {
  1.7967 +	        Tcl_DecrRefCount (bufObj);
  1.7968 +		bufObj = (Tcl_Obj*) NULL;
  1.7969 +	    }
  1.7970 +	    return TCL_OK;
  1.7971 +	}
  1.7972 +
  1.7973 +	/*
  1.7974 +	 * For background copies, we only do one buffer per invocation so
  1.7975 +	 * we don't starve the rest of the system.
  1.7976 +	 */
  1.7977 +
  1.7978 +	if (cmdPtr) {
  1.7979 +	    /*
  1.7980 +	     * The first time we enter this code, there won't be a
  1.7981 +	     * channel handler established yet, so do it here.
  1.7982 +	     */
  1.7983 +
  1.7984 +	    if (mask == 0) {
  1.7985 +		Tcl_CreateChannelHandler(outChan, TCL_WRITABLE,
  1.7986 +			CopyEventProc, (ClientData) csPtr);
  1.7987 +	    }
  1.7988 +	    if (bufObj != (Tcl_Obj*) NULL) {
  1.7989 +	        Tcl_DecrRefCount (bufObj);
  1.7990 +		bufObj = (Tcl_Obj*) NULL;
  1.7991 +	    }
  1.7992 +	    return TCL_OK;
  1.7993 +	}
  1.7994 +    } /* while */
  1.7995 +
  1.7996 +    if (bufObj != (Tcl_Obj*) NULL) {
  1.7997 +        Tcl_DecrRefCount (bufObj);
  1.7998 +	bufObj = (Tcl_Obj*) NULL;
  1.7999 +    }
  1.8000 +
  1.8001 +    /*
  1.8002 +     * Make the callback or return the number of bytes transferred.
  1.8003 +     * The local total is used because StopCopy frees csPtr.
  1.8004 +     */
  1.8005 +
  1.8006 +    total = csPtr->total;
  1.8007 +    if (cmdPtr && interp) {
  1.8008 +	/*
  1.8009 +	 * Get a private copy of the command so we can mutate it
  1.8010 +	 * by adding arguments.  Note that StopCopy frees our saved
  1.8011 +	 * reference to the original command obj.
  1.8012 +	 */
  1.8013 +
  1.8014 +	cmdPtr = Tcl_DuplicateObj(cmdPtr);
  1.8015 +	Tcl_IncrRefCount(cmdPtr);
  1.8016 +	StopCopy(csPtr);
  1.8017 +	Tcl_Preserve((ClientData) interp);
  1.8018 +
  1.8019 +	Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewIntObj(total));
  1.8020 +	if (errObj) {
  1.8021 +	    Tcl_ListObjAppendElement(interp, cmdPtr, errObj);
  1.8022 +	}
  1.8023 +	if (Tcl_EvalObjEx(interp, cmdPtr, TCL_EVAL_GLOBAL) != TCL_OK) {
  1.8024 +	    Tcl_BackgroundError(interp);
  1.8025 +	    result = TCL_ERROR;
  1.8026 +	}
  1.8027 +	Tcl_DecrRefCount(cmdPtr);
  1.8028 +	Tcl_Release((ClientData) interp);
  1.8029 +    } else {
  1.8030 +	StopCopy(csPtr);
  1.8031 +	if (interp) {
  1.8032 +	    if (errObj) {
  1.8033 +		Tcl_SetObjResult(interp, errObj);
  1.8034 +		result = TCL_ERROR;
  1.8035 +	    } else {
  1.8036 +		Tcl_ResetResult(interp);
  1.8037 +		Tcl_SetIntObj(Tcl_GetObjResult(interp), total);
  1.8038 +	    }
  1.8039 +	}
  1.8040 +    }
  1.8041 +    return result;
  1.8042 +}
  1.8043 +
  1.8044 +/*
  1.8045 + *----------------------------------------------------------------------
  1.8046 + *
  1.8047 + * DoRead --
  1.8048 + *
  1.8049 + *	Reads a given number of bytes from a channel.
  1.8050 + *
  1.8051 + *	No encoding conversions are applied to the bytes being read.
  1.8052 + *
  1.8053 + * Results:
  1.8054 + *	The number of characters read, or -1 on error. Use Tcl_GetErrno()
  1.8055 + *	to retrieve the error code for the error that occurred.
  1.8056 + *
  1.8057 + * Side effects:
  1.8058 + *	May cause input to be buffered.
  1.8059 + *
  1.8060 + *----------------------------------------------------------------------
  1.8061 + */
  1.8062 +
  1.8063 +static int
  1.8064 +DoRead(chanPtr, bufPtr, toRead)
  1.8065 +    Channel *chanPtr;		/* The channel from which to read. */
  1.8066 +    char *bufPtr;		/* Where to store input read. */
  1.8067 +    int toRead;			/* Maximum number of bytes to read. */
  1.8068 +{
  1.8069 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.8070 +    int copied;			/* How many characters were copied into
  1.8071 +                                 * the result string? */
  1.8072 +    int copiedNow;		/* How many characters were copied from
  1.8073 +                                 * the current input buffer? */
  1.8074 +    int result;			/* Of calling GetInput. */
  1.8075 +
  1.8076 +    /*
  1.8077 +     * If we have not encountered a sticky EOF, clear the EOF bit. Either
  1.8078 +     * way clear the BLOCKED bit. We want to discover these anew during
  1.8079 +     * each operation.
  1.8080 +     */
  1.8081 +
  1.8082 +    if (!(statePtr->flags & CHANNEL_STICKY_EOF)) {
  1.8083 +        statePtr->flags &= ~CHANNEL_EOF;
  1.8084 +    }
  1.8085 +    statePtr->flags &= ~(CHANNEL_BLOCKED | CHANNEL_NEED_MORE_DATA);
  1.8086 +    
  1.8087 +    for (copied = 0; copied < toRead; copied += copiedNow) {
  1.8088 +        copiedNow = CopyAndTranslateBuffer(statePtr, bufPtr + copied,
  1.8089 +                toRead - copied);
  1.8090 +        if (copiedNow == 0) {
  1.8091 +            if (statePtr->flags & CHANNEL_EOF) {
  1.8092 +		goto done;
  1.8093 +            }
  1.8094 +            if (statePtr->flags & CHANNEL_BLOCKED) {
  1.8095 +                if (statePtr->flags & CHANNEL_NONBLOCKING) {
  1.8096 +		    goto done;
  1.8097 +                }
  1.8098 +                statePtr->flags &= (~(CHANNEL_BLOCKED));
  1.8099 +            }
  1.8100 +            result = GetInput(chanPtr);
  1.8101 +            if (result != 0) {
  1.8102 +                if (result != EAGAIN) {
  1.8103 +                    copied = -1;
  1.8104 +                }
  1.8105 +		goto done;
  1.8106 +            }
  1.8107 +        }
  1.8108 +    }
  1.8109 +
  1.8110 +    statePtr->flags &= (~(CHANNEL_BLOCKED));
  1.8111 +
  1.8112 +    done:
  1.8113 +    /*
  1.8114 +     * Update the notifier state so we don't block while there is still
  1.8115 +     * data in the buffers.
  1.8116 +     */
  1.8117 +
  1.8118 +    UpdateInterest(chanPtr);
  1.8119 +    return copied;
  1.8120 +}
  1.8121 +
  1.8122 +/*
  1.8123 + *----------------------------------------------------------------------
  1.8124 + *
  1.8125 + * CopyAndTranslateBuffer --
  1.8126 + *
  1.8127 + *	Copy at most one buffer of input to the result space, doing
  1.8128 + *	eol translations according to mode in effect currently.
  1.8129 + *
  1.8130 + * Results:
  1.8131 + *	Number of bytes stored in the result buffer (as opposed to the
  1.8132 + *	number of bytes read from the channel).  May return
  1.8133 + *	zero if no input is available to be translated.
  1.8134 + *
  1.8135 + * Side effects:
  1.8136 + *	Consumes buffered input. May deallocate one buffer.
  1.8137 + *
  1.8138 + *----------------------------------------------------------------------
  1.8139 + */
  1.8140 +
  1.8141 +static int
  1.8142 +CopyAndTranslateBuffer(statePtr, result, space)
  1.8143 +    ChannelState *statePtr;	/* Channel state from which to read input. */
  1.8144 +    char *result;		/* Where to store the copied input. */
  1.8145 +    int space;			/* How many bytes are available in result
  1.8146 +                                 * to store the copied input? */
  1.8147 +{
  1.8148 +    ChannelBuffer *bufPtr;	/* The buffer from which to copy bytes. */
  1.8149 +    int bytesInBuffer;		/* How many bytes are available to be
  1.8150 +                                 * copied in the current input buffer? */
  1.8151 +    int copied;			/* How many characters were already copied
  1.8152 +                                 * into the destination space? */
  1.8153 +    int i;			/* Iterates over the copied input looking
  1.8154 +                                 * for the input eofChar. */
  1.8155 +    
  1.8156 +    /*
  1.8157 +     * If there is no input at all, return zero. The invariant is that either
  1.8158 +     * there is no buffer in the queue, or if the first buffer is empty, it
  1.8159 +     * is also the last buffer (and thus there is no input in the queue).
  1.8160 +     * Note also that if the buffer is empty, we leave it in the queue.
  1.8161 +     */
  1.8162 +    
  1.8163 +    if (statePtr->inQueueHead == (ChannelBuffer *) NULL) {
  1.8164 +        return 0;
  1.8165 +    }
  1.8166 +    bufPtr = statePtr->inQueueHead;
  1.8167 +    bytesInBuffer = bufPtr->nextAdded - bufPtr->nextRemoved;
  1.8168 +
  1.8169 +    copied = 0;
  1.8170 +    switch (statePtr->inputTranslation) {
  1.8171 +        case TCL_TRANSLATE_LF: {
  1.8172 +            if (bytesInBuffer == 0) {
  1.8173 +                return 0;
  1.8174 +            }
  1.8175 +
  1.8176 +	    /*
  1.8177 +             * Copy the current chunk into the result buffer.
  1.8178 +             */
  1.8179 +
  1.8180 +	    if (bytesInBuffer < space) {
  1.8181 +		space = bytesInBuffer;
  1.8182 +	    }
  1.8183 +	    memcpy((VOID *) result,
  1.8184 +		    (VOID *) (bufPtr->buf + bufPtr->nextRemoved),
  1.8185 +		    (size_t) space);
  1.8186 +	    bufPtr->nextRemoved += space;
  1.8187 +	    copied = space;
  1.8188 +            break;
  1.8189 +	}
  1.8190 +        case TCL_TRANSLATE_CR: {
  1.8191 +	    char *end;
  1.8192 +	    
  1.8193 +            if (bytesInBuffer == 0) {
  1.8194 +                return 0;
  1.8195 +            }
  1.8196 +
  1.8197 +	    /*
  1.8198 +             * Copy the current chunk into the result buffer, then
  1.8199 +             * replace all \r with \n.
  1.8200 +             */
  1.8201 +
  1.8202 +	    if (bytesInBuffer < space) {
  1.8203 +		space = bytesInBuffer;
  1.8204 +	    }
  1.8205 +	    memcpy((VOID *) result,
  1.8206 +		    (VOID *) (bufPtr->buf + bufPtr->nextRemoved),
  1.8207 +		    (size_t) space);
  1.8208 +	    bufPtr->nextRemoved += space;
  1.8209 +	    copied = space;
  1.8210 +
  1.8211 +	    for (end = result + copied; result < end; result++) {
  1.8212 +		if (*result == '\r') {
  1.8213 +		    *result = '\n';
  1.8214 +		}
  1.8215 +            }
  1.8216 +            break;
  1.8217 +	}
  1.8218 +        case TCL_TRANSLATE_CRLF: {
  1.8219 +	    char *src, *end, *dst;
  1.8220 +	    int curByte;
  1.8221 +	    
  1.8222 +            /*
  1.8223 +             * If there is a held-back "\r" at EOF, produce it now.
  1.8224 +             */
  1.8225 +            
  1.8226 +	    if (bytesInBuffer == 0) {
  1.8227 +                if ((statePtr->flags & (INPUT_SAW_CR | CHANNEL_EOF)) ==
  1.8228 +                        (INPUT_SAW_CR | CHANNEL_EOF)) {
  1.8229 +                    result[0] = '\r';
  1.8230 +                    statePtr->flags &= ~INPUT_SAW_CR;
  1.8231 +                    return 1;
  1.8232 +                }
  1.8233 +                return 0;
  1.8234 +            }
  1.8235 +
  1.8236 +            /*
  1.8237 +             * Copy the current chunk and replace "\r\n" with "\n"
  1.8238 +             * (but not standalone "\r"!).
  1.8239 +             */
  1.8240 +
  1.8241 +	    if (bytesInBuffer < space) {
  1.8242 +		space = bytesInBuffer;
  1.8243 +	    }
  1.8244 +	    memcpy((VOID *) result,
  1.8245 +		    (VOID *) (bufPtr->buf + bufPtr->nextRemoved),
  1.8246 +		    (size_t) space);
  1.8247 +	    bufPtr->nextRemoved += space;
  1.8248 +	    copied = space;
  1.8249 +
  1.8250 +	    end = result + copied;
  1.8251 +	    dst = result;
  1.8252 +	    for (src = result; src < end; src++) {
  1.8253 +		curByte = *src;
  1.8254 +		if (curByte == '\n') {
  1.8255 +                    statePtr->flags &= ~INPUT_SAW_CR;
  1.8256 +		} else if (statePtr->flags & INPUT_SAW_CR) {
  1.8257 +		    statePtr->flags &= ~INPUT_SAW_CR;
  1.8258 +		    *dst = '\r';
  1.8259 +		    dst++;
  1.8260 +		}
  1.8261 +		if (curByte == '\r') {
  1.8262 +		    statePtr->flags |= INPUT_SAW_CR;
  1.8263 +		} else {
  1.8264 +		    *dst = (char) curByte;
  1.8265 +		    dst++;
  1.8266 +		}
  1.8267 +	    }
  1.8268 +	    copied = dst - result;
  1.8269 +	    break;
  1.8270 +	}
  1.8271 +        case TCL_TRANSLATE_AUTO: {
  1.8272 +	    char *src, *end, *dst;
  1.8273 +	    int curByte;
  1.8274 +	
  1.8275 +            if (bytesInBuffer == 0) {
  1.8276 +                return 0;
  1.8277 +            }
  1.8278 +
  1.8279 +            /*
  1.8280 +             * Loop over the current buffer, converting "\r" and "\r\n"
  1.8281 +             * to "\n".
  1.8282 +             */
  1.8283 +
  1.8284 +	    if (bytesInBuffer < space) {
  1.8285 +		space = bytesInBuffer;
  1.8286 +	    }
  1.8287 +	    memcpy((VOID *) result,
  1.8288 +		    (VOID *) (bufPtr->buf + bufPtr->nextRemoved),
  1.8289 +		    (size_t) space);
  1.8290 +	    bufPtr->nextRemoved += space;
  1.8291 +	    copied = space;
  1.8292 +
  1.8293 +	    end = result + copied;
  1.8294 +	    dst = result;
  1.8295 +	    for (src = result; src < end; src++) {
  1.8296 +		curByte = *src;
  1.8297 +		if (curByte == '\r') {
  1.8298 +		    statePtr->flags |= INPUT_SAW_CR;
  1.8299 +		    *dst = '\n';
  1.8300 +		    dst++;
  1.8301 +		} else {
  1.8302 +		    if ((curByte != '\n') || 
  1.8303 +			    !(statePtr->flags & INPUT_SAW_CR)) {
  1.8304 +			*dst = (char) curByte;
  1.8305 +			dst++;
  1.8306 +		    }
  1.8307 +		    statePtr->flags &= ~INPUT_SAW_CR;
  1.8308 +		}
  1.8309 +	    }
  1.8310 +	    copied = dst - result;
  1.8311 +            break;
  1.8312 +	}
  1.8313 +        default: {
  1.8314 +            panic("unknown eol translation mode");
  1.8315 +	}
  1.8316 +    }
  1.8317 +
  1.8318 +    /*
  1.8319 +     * If an in-stream EOF character is set for this channel, check that
  1.8320 +     * the input we copied so far does not contain the EOF char.  If it does,
  1.8321 +     * copy only up to and excluding that character.
  1.8322 +     */
  1.8323 +    
  1.8324 +    if (statePtr->inEofChar != 0) {
  1.8325 +        for (i = 0; i < copied; i++) {
  1.8326 +            if (result[i] == (char) statePtr->inEofChar) {
  1.8327 +		/*
  1.8328 +		 * Set sticky EOF so that no further input is presented
  1.8329 +		 * to the caller.
  1.8330 +		 */
  1.8331 +		
  1.8332 +		statePtr->flags |= (CHANNEL_EOF | CHANNEL_STICKY_EOF);
  1.8333 +		statePtr->inputEncodingFlags |= TCL_ENCODING_END;
  1.8334 +		copied = i;
  1.8335 +                break;
  1.8336 +            }
  1.8337 +        }
  1.8338 +    }
  1.8339 +
  1.8340 +    /*
  1.8341 +     * If the current buffer is empty recycle it.
  1.8342 +     */
  1.8343 +
  1.8344 +    if (bufPtr->nextRemoved == bufPtr->nextAdded) {
  1.8345 +        statePtr->inQueueHead = bufPtr->nextPtr;
  1.8346 +        if (statePtr->inQueueHead == (ChannelBuffer *) NULL) {
  1.8347 +            statePtr->inQueueTail = (ChannelBuffer *) NULL;
  1.8348 +        }
  1.8349 +        RecycleBuffer(statePtr, bufPtr, 0);
  1.8350 +    }
  1.8351 +
  1.8352 +    /*
  1.8353 +     * Return the number of characters copied into the result buffer.
  1.8354 +     * This may be different from the number of bytes consumed, because
  1.8355 +     * of EOL translations.
  1.8356 +     */
  1.8357 +
  1.8358 +    return copied;
  1.8359 +}
  1.8360 +
  1.8361 +/*
  1.8362 + *----------------------------------------------------------------------
  1.8363 + *
  1.8364 + * CopyBuffer --
  1.8365 + *
  1.8366 + *	Copy at most one buffer of input to the result space.
  1.8367 + *
  1.8368 + * Results:
  1.8369 + *	Number of bytes stored in the result buffer.  May return
  1.8370 + *	zero if no input is available.
  1.8371 + *
  1.8372 + * Side effects:
  1.8373 + *	Consumes buffered input. May deallocate one buffer.
  1.8374 + *
  1.8375 + *----------------------------------------------------------------------
  1.8376 + */
  1.8377 +
  1.8378 +static int
  1.8379 +CopyBuffer(chanPtr, result, space)
  1.8380 +    Channel *chanPtr;		/* Channel from which to read input. */
  1.8381 +    char *result;		/* Where to store the copied input. */
  1.8382 +    int space;			/* How many bytes are available in result
  1.8383 +                                 * to store the copied input? */
  1.8384 +{
  1.8385 +    ChannelBuffer *bufPtr;	/* The buffer from which to copy bytes. */
  1.8386 +    int bytesInBuffer;		/* How many bytes are available to be
  1.8387 +                                 * copied in the current input buffer? */
  1.8388 +    int copied;			/* How many characters were already copied
  1.8389 +                                 * into the destination space? */
  1.8390 +    
  1.8391 +    /*
  1.8392 +     * If there is no input at all, return zero. The invariant is that
  1.8393 +     * either there is no buffer in the queue, or if the first buffer
  1.8394 +     * is empty, it is also the last buffer (and thus there is no
  1.8395 +     * input in the queue).  Note also that if the buffer is empty, we
  1.8396 +     * don't leave it in the queue, but recycle it.
  1.8397 +     */
  1.8398 +    
  1.8399 +    if (chanPtr->inQueueHead == (ChannelBuffer *) NULL) {
  1.8400 +        return 0;
  1.8401 +    }
  1.8402 +    bufPtr = chanPtr->inQueueHead;
  1.8403 +    bytesInBuffer = bufPtr->nextAdded - bufPtr->nextRemoved;
  1.8404 +
  1.8405 +    copied = 0;
  1.8406 +
  1.8407 +    if (bytesInBuffer == 0) {
  1.8408 +        RecycleBuffer(chanPtr->state, bufPtr, 0);
  1.8409 +	chanPtr->inQueueHead = (ChannelBuffer*) NULL;
  1.8410 +	chanPtr->inQueueTail = (ChannelBuffer*) NULL;
  1.8411 +        return 0;
  1.8412 +    }
  1.8413 +
  1.8414 +    /*
  1.8415 +     * Copy the current chunk into the result buffer.
  1.8416 +     */
  1.8417 +
  1.8418 +    if (bytesInBuffer < space) {
  1.8419 +        space = bytesInBuffer;
  1.8420 +    }
  1.8421 +
  1.8422 +    memcpy((VOID *) result,
  1.8423 +	   (VOID *) (bufPtr->buf + bufPtr->nextRemoved),
  1.8424 +	   (size_t) space);
  1.8425 +    bufPtr->nextRemoved += space;
  1.8426 +    copied = space;
  1.8427 +
  1.8428 +    /*
  1.8429 +     * We don't care about in-stream EOF characters here as the data
  1.8430 +     * read here may still flow through one or more transformations,
  1.8431 +     * i.e. is not in its final state yet.
  1.8432 +     */
  1.8433 +
  1.8434 +    /*
  1.8435 +     * If the current buffer is empty recycle it.
  1.8436 +     */
  1.8437 +
  1.8438 +    if (bufPtr->nextRemoved == bufPtr->nextAdded) {
  1.8439 +        chanPtr->inQueueHead = bufPtr->nextPtr;
  1.8440 +        if (chanPtr->inQueueHead == (ChannelBuffer *) NULL) {
  1.8441 +            chanPtr->inQueueTail = (ChannelBuffer *) NULL;
  1.8442 +        }
  1.8443 +        RecycleBuffer(chanPtr->state, bufPtr, 0);
  1.8444 +    }
  1.8445 +
  1.8446 +    /*
  1.8447 +     * Return the number of characters copied into the result buffer.
  1.8448 +     */
  1.8449 +
  1.8450 +    return copied;
  1.8451 +}
  1.8452 +
  1.8453 +/*
  1.8454 + *----------------------------------------------------------------------
  1.8455 + *
  1.8456 + * DoWrite --
  1.8457 + *
  1.8458 + *	Puts a sequence of characters into an output buffer, may queue the
  1.8459 + *	buffer for output if it gets full, and also remembers whether the
  1.8460 + *	current buffer is ready e.g. if it contains a newline and we are in
  1.8461 + *	line buffering mode.
  1.8462 + *
  1.8463 + * Results:
  1.8464 + *	The number of bytes written or -1 in case of error. If -1,
  1.8465 + *	Tcl_GetErrno will return the error code.
  1.8466 + *
  1.8467 + * Side effects:
  1.8468 + *	May buffer up output and may cause output to be produced on the
  1.8469 + *	channel.
  1.8470 + *
  1.8471 + *----------------------------------------------------------------------
  1.8472 + */
  1.8473 +
  1.8474 +static int
  1.8475 +DoWrite(chanPtr, src, srcLen)
  1.8476 +    Channel *chanPtr;			/* The channel to buffer output for. */
  1.8477 +    CONST char *src;			/* Data to write. */
  1.8478 +    int srcLen;				/* Number of bytes to write. */
  1.8479 +{
  1.8480 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.8481 +    ChannelBuffer *outBufPtr;		/* Current output buffer. */
  1.8482 +    int foundNewline;			/* Did we find a newline in output? */
  1.8483 +    char *dPtr;
  1.8484 +    CONST char *sPtr;			/* Search variables for newline. */
  1.8485 +    int crsent;				/* In CRLF eol translation mode,
  1.8486 +                                         * remember the fact that a CR was
  1.8487 +                                         * output to the channel without
  1.8488 +                                         * its following NL. */
  1.8489 +    int i;				/* Loop index for newline search. */
  1.8490 +    int destCopied;			/* How many bytes were used in this
  1.8491 +                                         * destination buffer to hold the
  1.8492 +                                         * output? */
  1.8493 +    int totalDestCopied;		/* How many bytes total were
  1.8494 +                                         * copied to the channel buffer? */
  1.8495 +    int srcCopied;			/* How many bytes were copied from
  1.8496 +                                         * the source string? */
  1.8497 +    char *destPtr;			/* Where in line to copy to? */
  1.8498 +
  1.8499 +    /*
  1.8500 +     * If we are in network (or windows) translation mode, record the fact
  1.8501 +     * that we have not yet sent a CR to the channel.
  1.8502 +     */
  1.8503 +
  1.8504 +    crsent = 0;
  1.8505 +    
  1.8506 +    /*
  1.8507 +     * Loop filling buffers and flushing them until all output has been
  1.8508 +     * consumed.
  1.8509 +     */
  1.8510 +
  1.8511 +    srcCopied = 0;
  1.8512 +    totalDestCopied = 0;
  1.8513 +
  1.8514 +    while (srcLen > 0) {
  1.8515 +        
  1.8516 +        /*
  1.8517 +         * Make sure there is a current output buffer to accept output.
  1.8518 +         */
  1.8519 +
  1.8520 +        if (statePtr->curOutPtr == (ChannelBuffer *) NULL) {
  1.8521 +            statePtr->curOutPtr = AllocChannelBuffer(statePtr->bufSize);
  1.8522 +        }
  1.8523 +
  1.8524 +        outBufPtr = statePtr->curOutPtr;
  1.8525 +
  1.8526 +        destCopied = outBufPtr->bufLength - outBufPtr->nextAdded;
  1.8527 +        if (destCopied > srcLen) {
  1.8528 +            destCopied = srcLen;
  1.8529 +        }
  1.8530 +        
  1.8531 +        destPtr = outBufPtr->buf + outBufPtr->nextAdded;
  1.8532 +        switch (statePtr->outputTranslation) {
  1.8533 +            case TCL_TRANSLATE_LF:
  1.8534 +                srcCopied = destCopied;
  1.8535 +                memcpy((VOID *) destPtr, (VOID *) src, (size_t) destCopied);
  1.8536 +                break;
  1.8537 +            case TCL_TRANSLATE_CR:
  1.8538 +                srcCopied = destCopied;
  1.8539 +                memcpy((VOID *) destPtr, (VOID *) src, (size_t) destCopied);
  1.8540 +                for (dPtr = destPtr; dPtr < destPtr + destCopied; dPtr++) {
  1.8541 +                    if (*dPtr == '\n') {
  1.8542 +                        *dPtr = '\r';
  1.8543 +                    }
  1.8544 +                }
  1.8545 +                break;
  1.8546 +            case TCL_TRANSLATE_CRLF:
  1.8547 +                for (srcCopied = 0, dPtr = destPtr, sPtr = src;
  1.8548 +                     dPtr < destPtr + destCopied;
  1.8549 +                     dPtr++, sPtr++, srcCopied++) {
  1.8550 +                    if (*sPtr == '\n') {
  1.8551 +                        if (crsent) {
  1.8552 +                            *dPtr = '\n';
  1.8553 +                            crsent = 0;
  1.8554 +                        } else {
  1.8555 +                            *dPtr = '\r';
  1.8556 +                            crsent = 1;
  1.8557 +                            sPtr--, srcCopied--;
  1.8558 +                        }
  1.8559 +                    } else {
  1.8560 +                        *dPtr = *sPtr;
  1.8561 +                    }
  1.8562 +                }
  1.8563 +                break;
  1.8564 +            case TCL_TRANSLATE_AUTO:
  1.8565 +                panic("Tcl_Write: AUTO output translation mode not supported");
  1.8566 +            default:
  1.8567 +                panic("Tcl_Write: unknown output translation mode");
  1.8568 +        }
  1.8569 +
  1.8570 +        /*
  1.8571 +         * The current buffer is ready for output if it is full, or if it
  1.8572 +         * contains a newline and this channel is line-buffered, or if it
  1.8573 +         * contains any output and this channel is unbuffered.
  1.8574 +         */
  1.8575 +
  1.8576 +        outBufPtr->nextAdded += destCopied;
  1.8577 +        if (!(statePtr->flags & BUFFER_READY)) {
  1.8578 +            if (outBufPtr->nextAdded == outBufPtr->bufLength) {
  1.8579 +                statePtr->flags |= BUFFER_READY;
  1.8580 +            } else if (statePtr->flags & CHANNEL_LINEBUFFERED) {
  1.8581 +                for (sPtr = src, i = 0, foundNewline = 0;
  1.8582 +		     (i < srcCopied) && (!foundNewline);
  1.8583 +		     i++, sPtr++) {
  1.8584 +                    if (*sPtr == '\n') {
  1.8585 +                        foundNewline = 1;
  1.8586 +                        break;
  1.8587 +                    }
  1.8588 +                }
  1.8589 +                if (foundNewline) {
  1.8590 +                    statePtr->flags |= BUFFER_READY;
  1.8591 +                }
  1.8592 +            } else if (statePtr->flags & CHANNEL_UNBUFFERED) {
  1.8593 +                statePtr->flags |= BUFFER_READY;
  1.8594 +            }
  1.8595 +        }
  1.8596 +        
  1.8597 +        totalDestCopied += srcCopied;
  1.8598 +        src += srcCopied;
  1.8599 +        srcLen -= srcCopied;
  1.8600 +
  1.8601 +        if (statePtr->flags & BUFFER_READY) {
  1.8602 +            if (FlushChannel(NULL, chanPtr, 0) != 0) {
  1.8603 +                return -1;
  1.8604 +            }
  1.8605 +        }
  1.8606 +    } /* Closes "while" */
  1.8607 +
  1.8608 +    return totalDestCopied;
  1.8609 +}
  1.8610 +
  1.8611 +/*
  1.8612 + *----------------------------------------------------------------------
  1.8613 + *
  1.8614 + * CopyEventProc --
  1.8615 + *
  1.8616 + *	This routine is invoked as a channel event handler for
  1.8617 + *	the background copy operation.  It is just a trivial wrapper
  1.8618 + *	around the CopyData routine.
  1.8619 + *
  1.8620 + * Results:
  1.8621 + *	None.
  1.8622 + *
  1.8623 + * Side effects:
  1.8624 + *	None.
  1.8625 + *
  1.8626 + *----------------------------------------------------------------------
  1.8627 + */
  1.8628 +
  1.8629 +static void
  1.8630 +CopyEventProc(clientData, mask)
  1.8631 +    ClientData clientData;
  1.8632 +    int mask;
  1.8633 +{
  1.8634 +    (void) CopyData((CopyState *)clientData, mask);
  1.8635 +}
  1.8636 +
  1.8637 +/*
  1.8638 + *----------------------------------------------------------------------
  1.8639 + *
  1.8640 + * StopCopy --
  1.8641 + *
  1.8642 + *	This routine halts a copy that is in progress.
  1.8643 + *
  1.8644 + * Results:
  1.8645 + *	None.
  1.8646 + *
  1.8647 + * Side effects:
  1.8648 + *	Removes any pending channel handlers and restores the blocking
  1.8649 + *	and buffering modes of the channels.  The CopyState is freed.
  1.8650 + *
  1.8651 + *----------------------------------------------------------------------
  1.8652 + */
  1.8653 +
  1.8654 +static void
  1.8655 +StopCopy(csPtr)
  1.8656 +    CopyState *csPtr;		/* State for bg copy to stop . */
  1.8657 +{
  1.8658 +    ChannelState *inStatePtr, *outStatePtr;
  1.8659 +    int nonBlocking;
  1.8660 +
  1.8661 +    if (!csPtr) {
  1.8662 +	return;
  1.8663 +    }
  1.8664 +
  1.8665 +    inStatePtr	= csPtr->readPtr->state;
  1.8666 +    outStatePtr	= csPtr->writePtr->state;
  1.8667 +
  1.8668 +    /*
  1.8669 +     * Restore the old blocking mode and output buffering mode.
  1.8670 +     */
  1.8671 +
  1.8672 +    nonBlocking = (csPtr->readFlags & CHANNEL_NONBLOCKING);
  1.8673 +    if (nonBlocking != (inStatePtr->flags & CHANNEL_NONBLOCKING)) {
  1.8674 +	SetBlockMode(NULL, csPtr->readPtr,
  1.8675 +		nonBlocking ? TCL_MODE_NONBLOCKING : TCL_MODE_BLOCKING);
  1.8676 +    }
  1.8677 +    if (csPtr->readPtr != csPtr->writePtr) {
  1.8678 +	nonBlocking = (csPtr->writeFlags & CHANNEL_NONBLOCKING);
  1.8679 +	if (nonBlocking != (outStatePtr->flags & CHANNEL_NONBLOCKING)) {
  1.8680 +	    SetBlockMode(NULL, csPtr->writePtr,
  1.8681 +		    nonBlocking ? TCL_MODE_NONBLOCKING : TCL_MODE_BLOCKING);
  1.8682 +	}
  1.8683 +    }
  1.8684 +    outStatePtr->flags &= ~(CHANNEL_LINEBUFFERED | CHANNEL_UNBUFFERED);
  1.8685 +    outStatePtr->flags |=
  1.8686 +	csPtr->writeFlags & (CHANNEL_LINEBUFFERED | CHANNEL_UNBUFFERED);
  1.8687 +
  1.8688 +    if (csPtr->cmdPtr) {
  1.8689 +	Tcl_DeleteChannelHandler((Tcl_Channel)csPtr->readPtr, CopyEventProc,
  1.8690 +		(ClientData)csPtr);
  1.8691 +	if (csPtr->readPtr != csPtr->writePtr) {
  1.8692 +	    Tcl_DeleteChannelHandler((Tcl_Channel)csPtr->writePtr,
  1.8693 +		    CopyEventProc, (ClientData)csPtr);
  1.8694 +	}
  1.8695 +        Tcl_DecrRefCount(csPtr->cmdPtr);
  1.8696 +    }
  1.8697 +    inStatePtr->csPtr  = NULL;
  1.8698 +    outStatePtr->csPtr = NULL;
  1.8699 +    ckfree((char*) csPtr);
  1.8700 +}
  1.8701 +
  1.8702 +/*
  1.8703 + *----------------------------------------------------------------------
  1.8704 + *
  1.8705 + * StackSetBlockMode --
  1.8706 + *
  1.8707 + *	This function sets the blocking mode for a channel, iterating
  1.8708 + *	through each channel in a stack and updates the state flags.
  1.8709 + *
  1.8710 + * Results:
  1.8711 + *	0 if OK, result code from failed blockModeProc otherwise.
  1.8712 + *
  1.8713 + * Side effects:
  1.8714 + *	Modifies the blocking mode of the channel and possibly generates
  1.8715 + *	an error.
  1.8716 + *
  1.8717 + *----------------------------------------------------------------------
  1.8718 + */
  1.8719 +
  1.8720 +static int
  1.8721 +StackSetBlockMode(chanPtr, mode)
  1.8722 +    Channel *chanPtr;		/* Channel to modify. */
  1.8723 +    int mode;			/* One of TCL_MODE_BLOCKING or
  1.8724 +				 * TCL_MODE_NONBLOCKING. */
  1.8725 +{
  1.8726 +    int result = 0;
  1.8727 +    Tcl_DriverBlockModeProc *blockModeProc;
  1.8728 +
  1.8729 +    /*
  1.8730 +     * Start at the top of the channel stack
  1.8731 +     */
  1.8732 +
  1.8733 +    chanPtr = chanPtr->state->topChanPtr;
  1.8734 +    while (chanPtr != (Channel *) NULL) {
  1.8735 +	blockModeProc = Tcl_ChannelBlockModeProc(chanPtr->typePtr);
  1.8736 +	if (blockModeProc != NULL) {
  1.8737 +	    result = (*blockModeProc) (chanPtr->instanceData, mode);
  1.8738 +	    if (result != 0) {
  1.8739 +		Tcl_SetErrno(result);
  1.8740 +		return result;
  1.8741 +	    }
  1.8742 +	}
  1.8743 +	chanPtr = chanPtr->downChanPtr;
  1.8744 +    }
  1.8745 +    return 0;
  1.8746 +}
  1.8747 +
  1.8748 +/*
  1.8749 + *----------------------------------------------------------------------
  1.8750 + *
  1.8751 + * SetBlockMode --
  1.8752 + *
  1.8753 + *	This function sets the blocking mode for a channel and updates
  1.8754 + *	the state flags.
  1.8755 + *
  1.8756 + * Results:
  1.8757 + *	A standard Tcl result.
  1.8758 + *
  1.8759 + * Side effects:
  1.8760 + *	Modifies the blocking mode of the channel and possibly generates
  1.8761 + *	an error.
  1.8762 + *
  1.8763 + *----------------------------------------------------------------------
  1.8764 + */
  1.8765 +
  1.8766 +static int
  1.8767 +SetBlockMode(interp, chanPtr, mode)
  1.8768 +    Tcl_Interp *interp;		/* Interp for error reporting. */
  1.8769 +    Channel *chanPtr;		/* Channel to modify. */
  1.8770 +    int mode;			/* One of TCL_MODE_BLOCKING or
  1.8771 +				 * TCL_MODE_NONBLOCKING. */
  1.8772 +{
  1.8773 +    ChannelState *statePtr = chanPtr->state;	/* state info for channel */
  1.8774 +    int result = 0;
  1.8775 +
  1.8776 +    result = StackSetBlockMode(chanPtr, mode);
  1.8777 +    if (result != 0) {
  1.8778 +	if (interp != (Tcl_Interp *) NULL) {
  1.8779 +	    Tcl_AppendResult(interp, "error setting blocking mode: ",
  1.8780 +		    Tcl_PosixError(interp), (char *) NULL);
  1.8781 +	}
  1.8782 +	return TCL_ERROR;
  1.8783 +    }
  1.8784 +    if (mode == TCL_MODE_BLOCKING) {
  1.8785 +	statePtr->flags &= (~(CHANNEL_NONBLOCKING | BG_FLUSH_SCHEDULED));
  1.8786 +    } else {
  1.8787 +	statePtr->flags |= CHANNEL_NONBLOCKING;
  1.8788 +    }
  1.8789 +    return TCL_OK;
  1.8790 +}
  1.8791 +
  1.8792 +/*
  1.8793 + *----------------------------------------------------------------------
  1.8794 + *
  1.8795 + * Tcl_GetChannelNames --
  1.8796 + *
  1.8797 + *	Return the names of all open channels in the interp.
  1.8798 + *
  1.8799 + * Results:
  1.8800 + *	TCL_OK or TCL_ERROR.
  1.8801 + *
  1.8802 + * Side effects:
  1.8803 + *	Interp result modified with list of channel names.
  1.8804 + *
  1.8805 + *----------------------------------------------------------------------
  1.8806 + */
  1.8807 +
  1.8808 +EXPORT_C int
  1.8809 +Tcl_GetChannelNames(interp)
  1.8810 +    Tcl_Interp *interp;		/* Interp for error reporting. */
  1.8811 +{
  1.8812 +    return Tcl_GetChannelNamesEx(interp, (char *) NULL);
  1.8813 +}
  1.8814 +
  1.8815 +/*
  1.8816 + *----------------------------------------------------------------------
  1.8817 + *
  1.8818 + * Tcl_GetChannelNamesEx --
  1.8819 + *
  1.8820 + *	Return the names of open channels in the interp filtered
  1.8821 + *	filtered through a pattern.  If pattern is NULL, it returns
  1.8822 + *	all the open channels.
  1.8823 + *
  1.8824 + * Results:
  1.8825 + *	TCL_OK or TCL_ERROR.
  1.8826 + *
  1.8827 + * Side effects:
  1.8828 + *	Interp result modified with list of channel names.
  1.8829 + *
  1.8830 + *----------------------------------------------------------------------
  1.8831 + */
  1.8832 +
  1.8833 +EXPORT_C int
  1.8834 +Tcl_GetChannelNamesEx(interp, pattern)
  1.8835 +    Tcl_Interp *interp;		/* Interp for error reporting. */
  1.8836 +    CONST char *pattern;	/* pattern to filter on. */
  1.8837 +{
  1.8838 +    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
  1.8839 +    ChannelState *statePtr;
  1.8840 +    CONST char *name;		/* name for channel */
  1.8841 +    Tcl_Obj *resultPtr;		/* pointer to result object */
  1.8842 +    Tcl_HashTable *hTblPtr;	/* Hash table of channels. */
  1.8843 +    Tcl_HashEntry *hPtr;	/* Search variable. */
  1.8844 +    Tcl_HashSearch hSearch;	/* Search variable. */
  1.8845 +
  1.8846 +    if (interp == (Tcl_Interp *) NULL) {
  1.8847 +	return TCL_OK;
  1.8848 +    }
  1.8849 +
  1.8850 +    /*
  1.8851 +     * Get the channel table that stores the channels registered
  1.8852 +     * for this interpreter.
  1.8853 +     */
  1.8854 +    hTblPtr	= GetChannelTable(interp);
  1.8855 +    resultPtr	= Tcl_GetObjResult(interp);
  1.8856 +
  1.8857 +    for (hPtr = Tcl_FirstHashEntry(hTblPtr, &hSearch);
  1.8858 +	 hPtr != (Tcl_HashEntry *) NULL;
  1.8859 +	 hPtr = Tcl_NextHashEntry(&hSearch)) {
  1.8860 +
  1.8861 +	statePtr = ((Channel *) Tcl_GetHashValue(hPtr))->state;
  1.8862 +        if (statePtr->topChanPtr == (Channel *) tsdPtr->stdinChannel) {
  1.8863 +	    name = "stdin";
  1.8864 +	} else if (statePtr->topChanPtr == (Channel *) tsdPtr->stdoutChannel) {
  1.8865 +	    name = "stdout";
  1.8866 +	} else if (statePtr->topChanPtr == (Channel *) tsdPtr->stderrChannel) {
  1.8867 +	    name = "stderr";
  1.8868 +	} else {
  1.8869 +	    /*
  1.8870 +	     * This is also stored in Tcl_GetHashKey(hTblPtr, hPtr),
  1.8871 +	     * but it's simpler to just grab the name from the statePtr.
  1.8872 +	     */
  1.8873 +	    name = statePtr->channelName;
  1.8874 +	}
  1.8875 +
  1.8876 +	if (((pattern == NULL) || Tcl_StringMatch(name, pattern)) &&
  1.8877 +		(Tcl_ListObjAppendElement(interp, resultPtr,
  1.8878 +			Tcl_NewStringObj(name, -1)) != TCL_OK)) {
  1.8879 +	    return TCL_ERROR;
  1.8880 +	}
  1.8881 +    }
  1.8882 +    return TCL_OK;
  1.8883 +}
  1.8884 +
  1.8885 +/*
  1.8886 + *----------------------------------------------------------------------
  1.8887 + *
  1.8888 + * Tcl_IsChannelRegistered --
  1.8889 + *
  1.8890 + *	Checks whether the channel is associated with the interp.
  1.8891 + *	See also Tcl_RegisterChannel and Tcl_UnregisterChannel.
  1.8892 + *
  1.8893 + * Results:
  1.8894 + *	0 if the channel is not registered in the interpreter, 1 else.
  1.8895 + *
  1.8896 + * Side effects:
  1.8897 + *	None.
  1.8898 + *
  1.8899 + *----------------------------------------------------------------------
  1.8900 + */
  1.8901 +
  1.8902 +EXPORT_C int
  1.8903 +Tcl_IsChannelRegistered (interp, chan)
  1.8904 +     Tcl_Interp* interp;	/* The interp to query of the channel */
  1.8905 +     Tcl_Channel chan;		/* The channel to check */
  1.8906 +{
  1.8907 +    Tcl_HashTable	*hTblPtr;	/* Hash table of channels. */
  1.8908 +    Tcl_HashEntry	*hPtr;		/* Search variable. */
  1.8909 +    Channel		*chanPtr;	/* The real IO channel. */
  1.8910 +    ChannelState	*statePtr;	/* State of the real channel. */
  1.8911 +
  1.8912 +    /*
  1.8913 +     * Always check bottom-most channel in the stack.  This is the one
  1.8914 +     * that gets registered.
  1.8915 +     */
  1.8916 +    chanPtr = ((Channel *) chan)->state->bottomChanPtr;
  1.8917 +    statePtr = chanPtr->state;
  1.8918 +
  1.8919 +    hTblPtr = (Tcl_HashTable *) Tcl_GetAssocData(interp, "tclIO", NULL);
  1.8920 +    if (hTblPtr == (Tcl_HashTable *) NULL) {
  1.8921 +        return 0;
  1.8922 +    }
  1.8923 +    hPtr = Tcl_FindHashEntry(hTblPtr, statePtr->channelName);
  1.8924 +    if (hPtr == (Tcl_HashEntry *) NULL) {
  1.8925 +        return 0;
  1.8926 +    }
  1.8927 +    if ((Channel *) Tcl_GetHashValue(hPtr) != chanPtr) {
  1.8928 +        return 0;
  1.8929 +    }
  1.8930 +
  1.8931 +    return 1;
  1.8932 +}
  1.8933 +
  1.8934 +/*
  1.8935 + *----------------------------------------------------------------------
  1.8936 + *
  1.8937 + * Tcl_IsChannelShared --
  1.8938 + *
  1.8939 + *	Checks whether the channel is shared by multiple interpreters.
  1.8940 + *
  1.8941 + * Results:
  1.8942 + *	A boolean value (0 = Not shared, 1 = Shared).
  1.8943 + *
  1.8944 + * Side effects:
  1.8945 + *	None.
  1.8946 + *
  1.8947 + *----------------------------------------------------------------------
  1.8948 + */
  1.8949 +
  1.8950 +EXPORT_C int
  1.8951 +Tcl_IsChannelShared (chan)
  1.8952 +    Tcl_Channel chan;	/* The channel to query */
  1.8953 +{
  1.8954 +    ChannelState *statePtr = ((Channel *) chan)->state;
  1.8955 +					/* State of real channel structure. */
  1.8956 +
  1.8957 +    return ((statePtr->refCount > 1) ? 1 : 0);
  1.8958 +}
  1.8959 +
  1.8960 +/*
  1.8961 + *----------------------------------------------------------------------
  1.8962 + *
  1.8963 + * Tcl_IsChannelExisting --
  1.8964 + *
  1.8965 + *	Checks whether a channel of the given name exists in the
  1.8966 + *	(thread)-global list of all channels.
  1.8967 + *	See Tcl_GetChannelNamesEx for function exposed at the Tcl level.
  1.8968 + *
  1.8969 + * Results:
  1.8970 + *	A boolean value (0 = Does not exist, 1 = Does exist).
  1.8971 + *
  1.8972 + * Side effects:
  1.8973 + *	None.
  1.8974 + *
  1.8975 + *----------------------------------------------------------------------
  1.8976 + */
  1.8977 +
  1.8978 +EXPORT_C int
  1.8979 +Tcl_IsChannelExisting(chanName)
  1.8980 +    CONST char* chanName;	/* The name of the channel to look for. */
  1.8981 +{
  1.8982 +    ChannelState *statePtr;
  1.8983 +    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
  1.8984 +    CONST char *name;
  1.8985 +    int chanNameLen;
  1.8986 +
  1.8987 +    chanNameLen = strlen(chanName);
  1.8988 +    for (statePtr = tsdPtr->firstCSPtr;
  1.8989 +	 statePtr != NULL;
  1.8990 +	 statePtr = statePtr->nextCSPtr) {
  1.8991 +        if (statePtr->topChanPtr == (Channel *) tsdPtr->stdinChannel) {
  1.8992 +	    name = "stdin";
  1.8993 +	} else if (statePtr->topChanPtr == (Channel *) tsdPtr->stdoutChannel) {
  1.8994 +	    name = "stdout";
  1.8995 +	} else if (statePtr->topChanPtr == (Channel *) tsdPtr->stderrChannel) {
  1.8996 +	    name = "stderr";
  1.8997 +	} else {
  1.8998 +	    name = statePtr->channelName;
  1.8999 +	}
  1.9000 +
  1.9001 +	if ((*chanName == *name) &&
  1.9002 +		(memcmp(name, chanName, (size_t) chanNameLen) == 0)) {
  1.9003 +	    return 1;
  1.9004 +	}
  1.9005 +    }
  1.9006 +
  1.9007 +    return 0;
  1.9008 +}
  1.9009 +
  1.9010 +/*
  1.9011 + *----------------------------------------------------------------------
  1.9012 + *
  1.9013 + * Tcl_ChannelName --
  1.9014 + *
  1.9015 + *	Return the name of the channel type.
  1.9016 + *
  1.9017 + * Results:
  1.9018 + *	A pointer the name of the channel type.
  1.9019 + *
  1.9020 + * Side effects:
  1.9021 + *	None.
  1.9022 + *
  1.9023 + *----------------------------------------------------------------------
  1.9024 + */
  1.9025 +
  1.9026 +EXPORT_C CONST char *
  1.9027 +Tcl_ChannelName(chanTypePtr)
  1.9028 +    Tcl_ChannelType *chanTypePtr;	/* Pointer to channel type. */
  1.9029 +{
  1.9030 +    return chanTypePtr->typeName;
  1.9031 +}
  1.9032 +
  1.9033 +/*
  1.9034 + *----------------------------------------------------------------------
  1.9035 + *
  1.9036 + * Tcl_ChannelVersion --
  1.9037 + *
  1.9038 + *	Return the of version of the channel type.
  1.9039 + *
  1.9040 + * Results:
  1.9041 + *	One of the TCL_CHANNEL_VERSION_* constants from tcl.h
  1.9042 + *
  1.9043 + * Side effects:
  1.9044 + *	None.
  1.9045 + *
  1.9046 + *----------------------------------------------------------------------
  1.9047 + */
  1.9048 +
  1.9049 +EXPORT_C Tcl_ChannelTypeVersion
  1.9050 +Tcl_ChannelVersion(chanTypePtr)
  1.9051 +    Tcl_ChannelType *chanTypePtr;	/* Pointer to channel type. */
  1.9052 +{
  1.9053 +    if (chanTypePtr->version == TCL_CHANNEL_VERSION_2) {
  1.9054 +	return TCL_CHANNEL_VERSION_2;
  1.9055 +    } else if (chanTypePtr->version == TCL_CHANNEL_VERSION_3) {
  1.9056 +	return TCL_CHANNEL_VERSION_3;
  1.9057 +    } else if (chanTypePtr->version == TCL_CHANNEL_VERSION_4) {
  1.9058 +	return TCL_CHANNEL_VERSION_4;
  1.9059 +    } else {
  1.9060 +	/*
  1.9061 +	 * In <v2 channel versions, the version field is occupied
  1.9062 +	 * by the Tcl_DriverBlockModeProc
  1.9063 +	 */
  1.9064 +	return TCL_CHANNEL_VERSION_1;
  1.9065 +    }
  1.9066 +}
  1.9067 +
  1.9068 +/*
  1.9069 + *----------------------------------------------------------------------
  1.9070 + *
  1.9071 + * HaveVersion --
  1.9072 + *
  1.9073 + *	Return whether a channel type is (at least) of a given version.
  1.9074 + *
  1.9075 + * Results:
  1.9076 + *	True if the minimum version is exceeded by the version actually
  1.9077 + *	present.
  1.9078 + *
  1.9079 + * Side effects:
  1.9080 + *	None.
  1.9081 + *
  1.9082 + *----------------------------------------------------------------------
  1.9083 + */
  1.9084 +
  1.9085 +static int
  1.9086 +HaveVersion(chanTypePtr, minimumVersion)
  1.9087 +    Tcl_ChannelType *chanTypePtr;
  1.9088 +    Tcl_ChannelTypeVersion minimumVersion;
  1.9089 +{
  1.9090 +    Tcl_ChannelTypeVersion actualVersion = Tcl_ChannelVersion(chanTypePtr);
  1.9091 +
  1.9092 +    return ((int)actualVersion) >= ((int)minimumVersion);
  1.9093 +}
  1.9094 +
  1.9095 +/*
  1.9096 + *----------------------------------------------------------------------
  1.9097 + *
  1.9098 + * Tcl_ChannelBlockModeProc --
  1.9099 + *
  1.9100 + *	Return the Tcl_DriverBlockModeProc of the channel type.
  1.9101 + *
  1.9102 + * Results:
  1.9103 + *	A pointer to the proc.
  1.9104 + *
  1.9105 + * Side effects:
  1.9106 + *	None.
  1.9107 + *
  1.9108 + *---------------------------------------------------------------------- */
  1.9109 +
  1.9110 +EXPORT_C Tcl_DriverBlockModeProc *
  1.9111 +Tcl_ChannelBlockModeProc(chanTypePtr)
  1.9112 +    Tcl_ChannelType *chanTypePtr;	/* Pointer to channel type. */
  1.9113 +{
  1.9114 +    if (HaveVersion(chanTypePtr, TCL_CHANNEL_VERSION_2)) {
  1.9115 +	return chanTypePtr->blockModeProc;
  1.9116 +    } else {
  1.9117 +	/*
  1.9118 +	 * The v1 structure had the blockModeProc in a different place.
  1.9119 +	 */
  1.9120 +	return (Tcl_DriverBlockModeProc *) (chanTypePtr->version);
  1.9121 +    }
  1.9122 +}
  1.9123 +
  1.9124 +/*
  1.9125 + *----------------------------------------------------------------------
  1.9126 + *
  1.9127 + * Tcl_ChannelCloseProc --
  1.9128 + *
  1.9129 + *	Return the Tcl_DriverCloseProc of the channel type.
  1.9130 + *
  1.9131 + * Results:
  1.9132 + *	A pointer to the proc.
  1.9133 + *
  1.9134 + * Side effects:
  1.9135 + *	None.
  1.9136 + *
  1.9137 + *----------------------------------------------------------------------
  1.9138 + */
  1.9139 +
  1.9140 +EXPORT_C Tcl_DriverCloseProc *
  1.9141 +Tcl_ChannelCloseProc(chanTypePtr)
  1.9142 +    Tcl_ChannelType *chanTypePtr;	/* Pointer to channel type. */
  1.9143 +{
  1.9144 +    return chanTypePtr->closeProc;
  1.9145 +}
  1.9146 +
  1.9147 +/*
  1.9148 + *----------------------------------------------------------------------
  1.9149 + *
  1.9150 + * Tcl_ChannelClose2Proc --
  1.9151 + *
  1.9152 + *	Return the Tcl_DriverClose2Proc of the channel type.
  1.9153 + *
  1.9154 + * Results:
  1.9155 + *	A pointer to the proc.
  1.9156 + *
  1.9157 + * Side effects:
  1.9158 + *	None.
  1.9159 + *
  1.9160 + *----------------------------------------------------------------------
  1.9161 + */
  1.9162 +
  1.9163 +EXPORT_C Tcl_DriverClose2Proc *
  1.9164 +Tcl_ChannelClose2Proc(chanTypePtr)
  1.9165 +    Tcl_ChannelType *chanTypePtr;	/* Pointer to channel type. */
  1.9166 +{
  1.9167 +    return chanTypePtr->close2Proc;
  1.9168 +}
  1.9169 +
  1.9170 +/*
  1.9171 + *----------------------------------------------------------------------
  1.9172 + *
  1.9173 + * Tcl_ChannelInputProc --
  1.9174 + *
  1.9175 + *	Return the Tcl_DriverInputProc of the channel type.
  1.9176 + *
  1.9177 + * Results:
  1.9178 + *	A pointer to the proc.
  1.9179 + *
  1.9180 + * Side effects:
  1.9181 + *	None.
  1.9182 + *
  1.9183 + *----------------------------------------------------------------------
  1.9184 + */
  1.9185 +
  1.9186 +EXPORT_C Tcl_DriverInputProc *
  1.9187 +Tcl_ChannelInputProc(chanTypePtr)
  1.9188 +    Tcl_ChannelType *chanTypePtr;	/* Pointer to channel type. */
  1.9189 +{
  1.9190 +    return chanTypePtr->inputProc;
  1.9191 +}
  1.9192 +
  1.9193 +/*
  1.9194 + *----------------------------------------------------------------------
  1.9195 + *
  1.9196 + * Tcl_ChannelOutputProc --
  1.9197 + *
  1.9198 + *	Return the Tcl_DriverOutputProc of the channel type.
  1.9199 + *
  1.9200 + * Results:
  1.9201 + *	A pointer to the proc.
  1.9202 + *
  1.9203 + * Side effects:
  1.9204 + *	None.
  1.9205 + *
  1.9206 + *----------------------------------------------------------------------
  1.9207 + */
  1.9208 +
  1.9209 +EXPORT_C Tcl_DriverOutputProc *
  1.9210 +Tcl_ChannelOutputProc(chanTypePtr)
  1.9211 +    Tcl_ChannelType *chanTypePtr;	/* Pointer to channel type. */
  1.9212 +{
  1.9213 +    return chanTypePtr->outputProc;
  1.9214 +}
  1.9215 +
  1.9216 +/*
  1.9217 + *----------------------------------------------------------------------
  1.9218 + *
  1.9219 + * Tcl_ChannelSeekProc --
  1.9220 + *
  1.9221 + *	Return the Tcl_DriverSeekProc of the channel type.
  1.9222 + *
  1.9223 + * Results:
  1.9224 + *	A pointer to the proc.
  1.9225 + *
  1.9226 + * Side effects:
  1.9227 + *	None.
  1.9228 + *
  1.9229 + *----------------------------------------------------------------------
  1.9230 + */
  1.9231 +
  1.9232 +EXPORT_C Tcl_DriverSeekProc *
  1.9233 +Tcl_ChannelSeekProc(chanTypePtr)
  1.9234 +    Tcl_ChannelType *chanTypePtr;	/* Pointer to channel type. */
  1.9235 +{
  1.9236 +    return chanTypePtr->seekProc;
  1.9237 +}
  1.9238 +
  1.9239 +/*
  1.9240 + *----------------------------------------------------------------------
  1.9241 + *
  1.9242 + * Tcl_ChannelSetOptionProc --
  1.9243 + *
  1.9244 + *	Return the Tcl_DriverSetOptionProc of the channel type.
  1.9245 + *
  1.9246 + * Results:
  1.9247 + *	A pointer to the proc.
  1.9248 + *
  1.9249 + * Side effects:
  1.9250 + *	None.
  1.9251 + *
  1.9252 + *----------------------------------------------------------------------
  1.9253 + */
  1.9254 +
  1.9255 +EXPORT_C Tcl_DriverSetOptionProc *
  1.9256 +Tcl_ChannelSetOptionProc(chanTypePtr)
  1.9257 +    Tcl_ChannelType *chanTypePtr;	/* Pointer to channel type. */
  1.9258 +{
  1.9259 +    return chanTypePtr->setOptionProc;
  1.9260 +}
  1.9261 +
  1.9262 +/*
  1.9263 + *----------------------------------------------------------------------
  1.9264 + *
  1.9265 + * Tcl_ChannelGetOptionProc --
  1.9266 + *
  1.9267 + *	Return the Tcl_DriverGetOptionProc of the channel type.
  1.9268 + *
  1.9269 + * Results:
  1.9270 + *	A pointer to the proc.
  1.9271 + *
  1.9272 + * Side effects:
  1.9273 + *	None.
  1.9274 + *
  1.9275 + *----------------------------------------------------------------------
  1.9276 + */
  1.9277 +
  1.9278 +EXPORT_C Tcl_DriverGetOptionProc *
  1.9279 +Tcl_ChannelGetOptionProc(chanTypePtr)
  1.9280 +    Tcl_ChannelType *chanTypePtr;	/* Pointer to channel type. */
  1.9281 +{
  1.9282 +    return chanTypePtr->getOptionProc;
  1.9283 +}
  1.9284 +
  1.9285 +/*
  1.9286 + *----------------------------------------------------------------------
  1.9287 + *
  1.9288 + * Tcl_ChannelWatchProc --
  1.9289 + *
  1.9290 + *	Return the Tcl_DriverWatchProc of the channel type.
  1.9291 + *
  1.9292 + * Results:
  1.9293 + *	A pointer to the proc.
  1.9294 + *
  1.9295 + * Side effects:
  1.9296 + *	None.
  1.9297 + *
  1.9298 + *----------------------------------------------------------------------
  1.9299 + */
  1.9300 +
  1.9301 +EXPORT_C Tcl_DriverWatchProc *
  1.9302 +Tcl_ChannelWatchProc(chanTypePtr)
  1.9303 +    Tcl_ChannelType *chanTypePtr;	/* Pointer to channel type. */
  1.9304 +{
  1.9305 +    return chanTypePtr->watchProc;
  1.9306 +}
  1.9307 +
  1.9308 +/*
  1.9309 + *----------------------------------------------------------------------
  1.9310 + *
  1.9311 + * Tcl_ChannelGetHandleProc --
  1.9312 + *
  1.9313 + *	Return the Tcl_DriverGetHandleProc of the channel type.
  1.9314 + *
  1.9315 + * Results:
  1.9316 + *	A pointer to the proc.
  1.9317 + *
  1.9318 + * Side effects:
  1.9319 + *	None.
  1.9320 + *
  1.9321 + *----------------------------------------------------------------------
  1.9322 + */
  1.9323 +
  1.9324 +EXPORT_C Tcl_DriverGetHandleProc *
  1.9325 +Tcl_ChannelGetHandleProc(chanTypePtr)
  1.9326 +    Tcl_ChannelType *chanTypePtr;	/* Pointer to channel type. */
  1.9327 +{
  1.9328 +    return chanTypePtr->getHandleProc;
  1.9329 +}
  1.9330 +
  1.9331 +/*
  1.9332 + *----------------------------------------------------------------------
  1.9333 + *
  1.9334 + * Tcl_ChannelFlushProc --
  1.9335 + *
  1.9336 + *	Return the Tcl_DriverFlushProc of the channel type.
  1.9337 + *
  1.9338 + * Results:
  1.9339 + *	A pointer to the proc.
  1.9340 + *
  1.9341 + * Side effects:
  1.9342 + *	None.
  1.9343 + *
  1.9344 + *----------------------------------------------------------------------
  1.9345 + */
  1.9346 +
  1.9347 +EXPORT_C Tcl_DriverFlushProc *
  1.9348 +Tcl_ChannelFlushProc(chanTypePtr)
  1.9349 +    Tcl_ChannelType *chanTypePtr;	/* Pointer to channel type. */
  1.9350 +{
  1.9351 +    if (HaveVersion(chanTypePtr, TCL_CHANNEL_VERSION_2)) {
  1.9352 +	return chanTypePtr->flushProc;
  1.9353 +    } else {
  1.9354 +	return NULL;
  1.9355 +    }
  1.9356 +}
  1.9357 +
  1.9358 +/*
  1.9359 + *----------------------------------------------------------------------
  1.9360 + *
  1.9361 + * Tcl_ChannelHandlerProc --
  1.9362 + *
  1.9363 + *	Return the Tcl_DriverHandlerProc of the channel type.
  1.9364 + *
  1.9365 + * Results:
  1.9366 + *	A pointer to the proc.
  1.9367 + *
  1.9368 + * Side effects:
  1.9369 + *	None.
  1.9370 + *
  1.9371 + *----------------------------------------------------------------------
  1.9372 + */
  1.9373 +
  1.9374 +EXPORT_C Tcl_DriverHandlerProc *
  1.9375 +Tcl_ChannelHandlerProc(chanTypePtr)
  1.9376 +    Tcl_ChannelType *chanTypePtr;	/* Pointer to channel type. */
  1.9377 +{
  1.9378 +    if (HaveVersion(chanTypePtr, TCL_CHANNEL_VERSION_2)) {
  1.9379 +	return chanTypePtr->handlerProc;
  1.9380 +    } else {
  1.9381 +	return NULL;
  1.9382 +    }
  1.9383 +}
  1.9384 +
  1.9385 +/*
  1.9386 + *----------------------------------------------------------------------
  1.9387 + *
  1.9388 + * Tcl_ChannelWideSeekProc --
  1.9389 + *
  1.9390 + *	Return the Tcl_DriverWideSeekProc of the channel type.
  1.9391 + *
  1.9392 + * Results:
  1.9393 + *	A pointer to the proc.
  1.9394 + *
  1.9395 + * Side effects:
  1.9396 + *	None.
  1.9397 + *
  1.9398 + *----------------------------------------------------------------------
  1.9399 + */
  1.9400 +
  1.9401 +EXPORT_C Tcl_DriverWideSeekProc *
  1.9402 +Tcl_ChannelWideSeekProc(chanTypePtr)
  1.9403 +    Tcl_ChannelType *chanTypePtr;	/* Pointer to channel type. */
  1.9404 +{
  1.9405 +    if (HaveVersion(chanTypePtr, TCL_CHANNEL_VERSION_3)) {
  1.9406 +	return chanTypePtr->wideSeekProc;
  1.9407 +    } else {
  1.9408 +	return NULL;
  1.9409 +    }
  1.9410 +}
  1.9411 +
  1.9412 +/*
  1.9413 + *----------------------------------------------------------------------
  1.9414 + *
  1.9415 + * Tcl_ChannelThreadActionProc --
  1.9416 + *
  1.9417 + *	Return the Tcl_DriverThreadActionProc of the channel type.
  1.9418 + *
  1.9419 + * Results:
  1.9420 + *	A pointer to the proc.
  1.9421 + *
  1.9422 + * Side effects:
  1.9423 + *	None.
  1.9424 + *
  1.9425 + *----------------------------------------------------------------------
  1.9426 + */
  1.9427 +
  1.9428 +EXPORT_C Tcl_DriverThreadActionProc *
  1.9429 +Tcl_ChannelThreadActionProc(chanTypePtr)
  1.9430 +    Tcl_ChannelType *chanTypePtr;	/* Pointer to channel type. */
  1.9431 +{
  1.9432 +    if (HaveVersion(chanTypePtr, TCL_CHANNEL_VERSION_4)) {
  1.9433 +	return chanTypePtr->threadActionProc;
  1.9434 +    } else {
  1.9435 +	return NULL;
  1.9436 +    }
  1.9437 +}
  1.9438 +
  1.9439 +#if 0
  1.9440 +/* For future debugging work, a simple function to print the flags of
  1.9441 + * a channel in semi-readable form.
  1.9442 + */
  1.9443 +
  1.9444 +static int
  1.9445 +DumpFlags (str, flags)
  1.9446 +     char* str;
  1.9447 +     int flags;
  1.9448 +{
  1.9449 +  char buf [20];
  1.9450 +  int i = 0;
  1.9451 +
  1.9452 +  if (flags & TCL_READABLE)           {buf[i] = 'r';} else {buf [i]='_';}; i++;
  1.9453 +  if (flags & TCL_WRITABLE)           {buf[i] = 'w';} else {buf [i]='_';}; i++;
  1.9454 +  if (flags & CHANNEL_NONBLOCKING)    {buf[i] = 'n';} else {buf [i]='_';}; i++;
  1.9455 +  if (flags & CHANNEL_LINEBUFFERED)   {buf[i] = 'l';} else {buf [i]='_';}; i++;
  1.9456 +  if (flags & CHANNEL_UNBUFFERED)     {buf[i] = 'u';} else {buf [i]='_';}; i++;
  1.9457 +  if (flags & BUFFER_READY)           {buf[i] = 'R';} else {buf [i]='_';}; i++;
  1.9458 +  if (flags & BG_FLUSH_SCHEDULED)     {buf[i] = 'F';} else {buf [i]='_';}; i++;
  1.9459 +  if (flags & CHANNEL_CLOSED)         {buf[i] = 'c';} else {buf [i]='_';}; i++;
  1.9460 +  if (flags & CHANNEL_EOF)            {buf[i] = 'E';} else {buf [i]='_';}; i++;
  1.9461 +  if (flags & CHANNEL_STICKY_EOF)     {buf[i] = 'S';} else {buf [i]='_';}; i++;
  1.9462 +  if (flags & CHANNEL_BLOCKED)        {buf[i] = 'B';} else {buf [i]='_';}; i++;
  1.9463 +  if (flags & INPUT_SAW_CR)           {buf[i] = '/';} else {buf [i]='_';}; i++;
  1.9464 +  if (flags & INPUT_NEED_NL)          {buf[i] = '*';} else {buf [i]='_';}; i++;
  1.9465 +  if (flags & CHANNEL_DEAD)           {buf[i] = 'D';} else {buf [i]='_';}; i++;
  1.9466 +  if (flags & CHANNEL_RAW_MODE)       {buf[i] = 'R';} else {buf [i]='_';}; i++;
  1.9467 +#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
  1.9468 +  if (flags & CHANNEL_TIMER_FEV)      {buf[i] = 'T';} else {buf [i]='_';}; i++;
  1.9469 +  if (flags & CHANNEL_HAS_MORE_DATA)  {buf[i] = 'H';} else {buf [i]='_';}; i++;
  1.9470 +#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */
  1.9471 +  if (flags & CHANNEL_INCLOSE)        {buf[i] = 'x';} else {buf [i]='_';}; i++;
  1.9472 +  buf [i] ='\0';
  1.9473 +
  1.9474 +  fprintf (stderr,"%s: %s\n", str, buf); fflush(stderr);
  1.9475 +  return 0;
  1.9476 +}
  1.9477 +#endif