usr/src/lib/libbc/libc/stdio/common/setbuffer.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 /*
  28  * University Copyright- Copyright (c) 1982, 1986, 1988
  29  * The Regents of the University of California
  30  * All Rights Reserved
  31  *
  32  * University Acknowledgment- Portions of this document are derived from
  33  * software developed by the University of California, Berkeley, and its
  34  * contributors.
  35  */
  36
  37 #pragma ident   "%Z%%M% %I%     %E% SMI"
  38
  39 #include <stdio.h>
  40 #include <malloc.h>
  41 #include <unistd.h>
  42
  43 extern unsigned char (*_smbuf)[_SBFSIZ];
  44
  45 void
  46 setbuffer(FILE *iop, char *buf, int size)
  47 {
  48         int fno = fileno(iop);  /* file number */
  49
  50         if (iop->_base != NULL && iop->_flag&_IOMYBUF)
  51                 free((char *)iop->_base);
  52         iop->_flag &= ~(_IOMYBUF|_IONBF|_IOLBF);
  53         if ((iop->_base = (unsigned char *)buf) == NULL) {
  54                 iop->_flag |= _IONBF; /* file unbuffered except in fastio */
  55                 /* use small buffers reserved for this */
  56                 iop->_base = _smbuf[fno];
  57                 iop->_bufsiz = _SBFSIZ;
  58         } else {
  59                 /* regular buffered I/O, specified buffer size */
  60                 if (size <= 0)
  61                         return;
  62                 iop->_bufsiz = size;
  63         }
  64         iop->_ptr = iop->_base;
  65         iop->_cnt = 0;
  66 }
  67
  68 /*
  69  * set line buffering
  70  */
  71 int
  72 setlinebuf(FILE *iop)
  73 {
  74         char *buf;
  75
  76         fflush(iop);
  77         setbuffer(iop, NULL, 0);
  78         buf = (char *)malloc(128);
  79         if (buf != NULL) {
  80                 setbuffer(iop, buf, 128);
  81                 iop->_flag |= _IOLBF|_IOMYBUF;
  82         }
  83         return (0);
  84 }