usr/src/lib/libc/port/stdio/setbuf.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #include "lint.h"
  33 #include "file64.h"
  34 #include "mtlib.h"
  35 #include <sys/types.h>
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <thread.h>
  39 #include <synch.h>
  40 #include "stdiom.h"
  41
  42
  43 void
  44 setbuf(FILE *iop, char *abuf)
  45 {
  46         Uchar *buf = (Uchar *)abuf;
  47         int fno = GET_FD(iop);  /* file number */
  48         int size = BUFSIZ - _SMBFSZ;
  49         Uchar *temp;
  50         rmutex_t *lk;
  51
  52         FLOCKFILE(lk, iop);
  53         if ((iop->_base != 0) && (iop->_flag & _IOMYBUF))
  54                 free((char *)iop->_base - PUSHBACK);
  55         iop->_flag &= ~(_IOMYBUF | _IONBF | _IOLBF);
  56         if (buf == 0) {
  57                 iop->_flag |= _IONBF;
  58 #ifndef _STDIO_ALLOCATE
  59                 if (fno < 2) {
  60                         /* use special buffer for std{in,out} */
  61                         buf = (fno == 0) ? _sibuf : _sobuf;
  62                 } else  /* needed for ifndef */
  63 #endif
  64                 if (fno < _NFILE) {
  65                         buf = _smbuf[fno];
  66                         size = _SMBFSZ - PUSHBACK;
  67                 } else
  68                 if ((buf = (Uchar *)malloc(_SMBFSZ * sizeof (Uchar))) != 0) {
  69                         iop->_flag |= _IOMYBUF;
  70                         size = _SMBFSZ - PUSHBACK;
  71                 }
  72         } else {        /* regular buffered I/O, standard buffer size */
  73                 if (isatty(fno))
  74                         iop->_flag |= _IOLBF;
  75         }
  76         if (buf == 0) {
  77                 FUNLOCKFILE(lk);
  78                 return;         /* malloc() failed */
  79         }
  80         temp = buf + PUSHBACK;
  81         iop->_base = temp;
  82         _setbufend(iop, temp + size);
  83         iop->_ptr = temp;
  84         iop->_cnt = 0;
  85         FUNLOCKFILE(lk);
  86 }