xref: /titanic_41/usr/src/lib/libbc/libc/stdio/4.2/setbuf.c (revision e4b86885570d77af552e9cf94f142f4d744fb8c8)
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 		iop->_bufsiz = BUFSIZ;
58 	iop->_ptr = iop->_base;
59 	iop->_cnt = 0;
60 }
61