os/ossrv/genericopenlibs/cstdlib/LSTDIO/REFILL.C
author sl
Tue, 10 Jun 2014 14:32:02 +0200
changeset 1 260cb5ec6c19
permissions -rw-r--r--
Update contrib.
     1 /* REFILL.C
     2  * 
     3  * Portions Copyright (c) 1990-1999 Nokia Corporation and/or its subsidiary(-ies).
     4  * All rights reserved.
     5  */
     6 
     7 /* No user fns here.  Pesch 15apr92. */
     8 
     9 /*
    10  * Copyright (c) 1990 The Regents of the University of California.
    11  * All rights reserved.
    12  *
    13  * Redistribution and use in source and binary forms are permitted
    14  * provided that the above copyright notice and this paragraph are
    15  * duplicated in all such forms and that any documentation,
    16  * advertising materials, and other materials related to such
    17  * distribution and use acknowledge that the software was developed
    18  * by the University of California, Berkeley.  The name of the
    19  * University may not be used to endorse or promote products derived
    20  * from this software without specific prior written permission.
    21  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
    22  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
    23  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
    24  */
    25 
    26 #include <stdio_r.h>
    27 #include "LOCAL.H"
    28 #include <stdlib_r.h>
    29 
    30 static int
    31 lflush (FILE *fp)
    32 {
    33   if ((fp->_flags & (__SLBF | __SWR)) == (__SLBF | __SWR))
    34     return fflush (fp);
    35   return 0;
    36 }
    37 
    38 /*
    39  * Refill a stdio buffer.
    40  * Return EOF on eof or error, 0 otherwise.
    41  */
    42 
    43 int
    44 __srefill (register FILE * fp)
    45 {
    46   /* make sure stdio is set up */
    47 
    48   CHECK_INIT (fp);
    49 
    50   fp->_r = 0;			/* largely a convenience for callers */
    51 
    52   /* SysV does not make this test; take it out for compatibility */
    53   if (fp->_flags & __SEOF)
    54     return EOF;
    55 
    56   /* if not already reading, have to be reading and writing */
    57   if ((fp->_flags & __SRD) == 0)
    58     {
    59       if ((fp->_flags & __SRW) == 0)
    60 	return EOF;
    61       /* switch to reading */
    62       if (fp->_flags & __SWR)
    63 	{
    64 	  if (fflush (fp))
    65 	    return EOF;
    66 	  fp->_flags &= ~__SWR;
    67 	  fp->_w = 0;
    68 	  fp->_lbfsize = 0;
    69 	}
    70       fp->_flags |= __SRD;
    71     }
    72   else
    73     {
    74       /*
    75        * We were reading.  If there is an ungetc buffer,
    76        * we must have been reading from that.  Drop it,
    77        * restoring the previous buffer (if any).  If there
    78        * is anything in that buffer, return.
    79        */
    80       if (HASUB (fp))
    81 	{
    82 	  FREEUB (fp);
    83 	  if ((fp->_r = fp->_ur) != 0)
    84 	    {
    85 	      fp->_p = fp->_up;
    86 	      return 0;
    87 	    }
    88 	}
    89     }
    90 
    91   if (fp->_bf._base == NULL)
    92     __smakebuf (fp);
    93 
    94   /*
    95    * Before reading from a line buffered or unbuffered file,
    96    * flush all line buffered output files, per the ANSI C
    97    * standard.
    98    */
    99 
   100   if (fp->_flags & (__SLBF | __SNBF))
   101     (void) _fwalk (fp->_data, lflush);
   102   fp->_p = fp->_bf._base;
   103   fp->_r = (*fp->_read) (fp->_cookie, (char *) fp->_p, fp->_bf._size);
   104   fp->_flags &= ~__SMOD;	/* buffer contents are again pristine */
   105   if (fp->_r <= 0)
   106     {
   107       if (fp->_r == 0)
   108 	fp->_flags |= __SEOF;
   109       else
   110 	{
   111 	  fp->_r = 0;
   112 	  fp->_flags |= __SERR;
   113 	}
   114       return EOF;
   115     }
   116   return 0;
   117 }