usr/src/ucblib/libucb/port/gen/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 (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 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  22 /*        All Rights Reserved   */
  23
  24 /*
  25  * University Copyright- Copyright (c) 1982, 1986, 1988
  26  * The Regents of the University of California
  27  * All Rights Reserved
  28  *
  29  * University Acknowledgment- Portions of this document are derived from
  30  * software developed by the University of California, Berkeley, and its
  31  * contributors.
  32  */
  33
  34 /*
  35  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  36  * Use is subject to license terms.
  37  */
  38
  39 /*LINTLIBRARY*/
  40
  41 #include <sys/types.h>
  42 #include "file64.h"
  43 #include <stdio.h>
  44 #include "stdiom.h"
  45 #include <stdlib.h>
  46
  47 extern Uchar _smbuf[][_NFILE];
  48
  49 void
  50 setbuffer(FILE *iop, char *abuf, int asize)
  51 {
  52         Uchar *buf = (Uchar *)abuf;
  53         int fno = fileno(iop);  /* file number */
  54         int size = asize - _SMBFSZ;
  55         Uchar *temp;
  56
  57         if (iop->_base != 0 && iop->_flag & _IOMYBUF)
  58                 free((char *)iop->_base - PUSHBACK);
  59         iop->_flag &= ~(_IOMYBUF | _IONBF | _IOLBF);
  60         if (buf == 0) {
  61                 iop->_flag |= _IONBF;
  62                 if (fno < 2) {
  63                         /* use special buffer for std{in,out} */
  64                         buf = (fno == 0) ? _sibuf : _sobuf;
  65                         size = BUFSIZ - _SMBFSZ;
  66                 } else if (fno < _NFILE) {
  67                         buf = _smbuf[fno];
  68                         size = _SMBFSZ - PUSHBACK;
  69                 } else if ((buf = (Uchar *)malloc(_SMBFSZ * sizeof (Uchar))) !=
  70                     0) {
  71                         iop->_flag |= _IOMYBUF;
  72                         size = _SMBFSZ - PUSHBACK;
  73                 }
  74         } else /* regular buffered I/O, specified buffer size */ {
  75                 if (size <= 0)
  76                         return;
  77         }
  78         if (buf == 0)
  79                 return; /* malloc() failed */
  80         temp = buf + PUSHBACK;
  81         iop->_base = temp;
  82         _setbufend(iop, temp + size);
  83         iop->_ptr = temp;
  84         iop->_cnt = 0;
  85 }
  86
  87 /*
  88  * set line buffering
  89  */
  90
  91 int
  92 setlinebuf(FILE *iop)
  93 {
  94         char *buf;
  95
  96         (void) fflush(iop);
  97         setbuffer(iop, (char *)NULL, 0);
  98         buf = (char *)malloc(128);
  99         if (buf != NULL) {
 100                 setbuffer(iop, buf, 128);
 101                 iop->_flag |= _IOLBF|_IOMYBUF;
 102         }
 103         return (0);     /* returns no useful value, keep the same prototype */
 104 }