Symaptic: os/ossrv/genericopenlibs/cstdlib/LSTDIO/MAKEBUF.C@260cb5ec6c19

     1 /* MAKEBUF.C

     2  *

     3  * Portions Copyright (c) 1990-1999 Nokia Corporation and/or its subsidiary(-ies).

     4  * All rights reserved.

     5  */

     7 /* No user fns here.  Pesch 15apr92. */

     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  */

    26 #include <stdio_r.h>

    27 #include <stdlib_r.h>

    28 #include <sys/stat.h>

    29 #include <sys/types.h>

    30 #include <sys/unistd.h>

    32 #include "LOCAL.H"

    34 /*

    35  * Allocate a file buffer, or switch to unbuffered I/O.

    36  * Per the ANSI C standard, ALL tty devices default to line buffered.

    37  *

    38  * As a side effect, we set __SOPT or __SNPT (en/dis-able fseek

    39  * optimization) right after the _fstat() that finds the buffer size.

    40  */

    42 void

    43 __smakebuf (register FILE *fp)

    44 {

    45   register size_t size, couldbetty;

    46   register void* p;

    47   struct stat st;

    49   if (fp->_flags & __SNBF)

    50     {

    51       fp->_bf._base = fp->_p = fp->_nbuf;

    52       fp->_bf._size = 1;

    53       return;

    54     }

    55   if (fp->_file < 0 || _fstat_r (fp->_data, fp->_file, &st) < 0)

    56     {

    57       couldbetty = 0;

    58       size = BUFSIZ;

    59       /* do not try to optimise fseek() */

    60       fp->_flags |= __SNPT;

    61     }

    62   else

    63     {

    64       couldbetty = (st.st_mode & S_IFMT) == S_IFCHR;

    65       size = st.st_blksize <= 0 ? BUFSIZ : st.st_blksize;

    66       /*

    67        * Optimize fseek() only if it is a regular file.

    68        * (The test for __sseek is mainly paranoia.)

    69        */

    70       if ((st.st_mode & S_IFMT) == S_IFREG && fp->_seek == __sseek)

    71 	{

    72 	  fp->_flags |= __SOPT;

    73 	  fp->_blksize = st.st_blksize;

    74 	}

    75       else

    76 	fp->_flags |= __SNPT;

    77     }

    78   if ((p = _malloc_r (fp->_data, size)) == NULL)

    79     {

    80       fp->_flags |= __SNBF;

    81       fp->_bf._base = fp->_p = fp->_nbuf;

    82       fp->_bf._size = 1;

    83     }

    84   else

    85     {

    86       fp->_data->__cleanup = _cleanup_r;

    87       fp->_flags |= __SMBF;

    88       fp->_bf._base = fp->_p = (unsigned char *) p;

    89       fp->_bf._size = size;

    90       if (couldbetty && isatty (fp->_file))

    91 	fp->_flags |= __SLBF;

    92     }

    93 }

author	sl
	Tue, 10 Jun 2014 14:32:02 +0200
changeset 1	260cb5ec6c19
permissions	-rw-r--r--