usr/src/lib/libbc/libc/stdio/sys5/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, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 1986 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1984 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"  /* from S5R2 2.2 */
  31
  32 /*LINTLIBRARY*/
  33 #include <stdio.h>
  34
  35 extern void free();
  36 extern int isatty();
  37 extern unsigned char (*_smbuf)[_SBFSIZ];
  38 extern void _getsmbuf();
  39
  40 void
  41 setbuf(iop, buf)
  42 register FILE *iop;
  43 char    *buf;
  44 {
  45         register int fno = fileno(iop);  /* file number */
  46
  47         if(iop->_base != NULL && iop->_flag & _IOMYBUF)
  48                 free((char*)iop->_base);
  49         iop->_flag &= ~(_IOMYBUF | _IONBF | _IOLBF);
  50         if((iop->_base = (unsigned char*)buf) == NULL) {
  51                 iop->_flag |= _IONBF; /* file unbuffered except in fastio */
  52                 /* use small buffers reserved for this */
  53                 iop->_base = _smbuf[fno];
  54                 iop->_bufsiz = _SBFSIZ;
  55         }
  56         else {  /* regular buffered I/O, standard buffer size */
  57                 if (isatty(fno))
  58                         iop->_flag |= _IOLBF;
  59                 iop->_bufsiz = BUFSIZ;
  60         }
  61         iop->_ptr = iop->_base;
  62         iop->_cnt = 0;
  63 }