xref: /titanic_41/usr/src/lib/libbc/libc/stdio/common/setbuffer.c (revision 0bb073995ac5a95bd35f2dd790df1ea3d8c2d507)
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 }
85