xref: /illumos-gate/usr/src/ucblib/libucb/port/gen/setbuffer.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
40 
41 /*LINTLIBRARY*/
42 
43 #include <sys/types.h>
44 #include "file64.h"
45 #include <stdio.h>
46 #include "stdiom.h"
47 #include <stdlib.h>
48 
49 extern Uchar _smbuf[][_NFILE];
50 
51 void
52 setbuffer(FILE *iop, char *abuf, int asize)
53 {
54 	Uchar *buf = (Uchar *)abuf;
55 	int fno = fileno(iop);  /* file number */
56 	int size = asize - _SMBFSZ;
57 	Uchar *temp;
58 
59 	if (iop->_base != 0 && iop->_flag & _IOMYBUF)
60 		free((char *)iop->_base - PUSHBACK);
61 	iop->_flag &= ~(_IOMYBUF | _IONBF | _IOLBF);
62 	if (buf == 0) {
63 		iop->_flag |= _IONBF;
64 #ifndef _STDIO_ALLOCATE
65 		if (fno < 2) {
66 			/* use special buffer for std{in,out} */
67 			buf = (fno == 0) ? _sibuf : _sobuf;
68 			size = BUFSIZ - _SMBFSZ;
69 		} else /* needed for ifdef */
70 #endif
71 		if (fno < _NFILE) {
72 			buf = _smbuf[fno];
73 			size = _SMBFSZ - PUSHBACK;
74 		} else if ((buf = (Uchar *)malloc(_SMBFSZ * sizeof (Uchar))) !=
75 		    0) {
76 			iop->_flag |= _IOMYBUF;
77 			size = _SMBFSZ - PUSHBACK;
78 		}
79 	} else /* regular buffered I/O, specified buffer size */ {
80 		if (size <= 0)
81 			return;
82 	}
83 	if (buf == 0)
84 		return; /* malloc() failed */
85 	temp = buf + PUSHBACK;
86 	iop->_base = temp;
87 	_setbufend(iop, temp + size);
88 	iop->_ptr = temp;
89 	iop->_cnt = 0;
90 }
91 
92 /*
93  * set line buffering
94  */
95 
96 int
97 setlinebuf(FILE *iop)
98 {
99 	char *buf;
100 
101 	(void) fflush(iop);
102 	setbuffer(iop, (char *)NULL, 0);
103 	buf = (char *)malloc(128);
104 	if (buf != NULL) {
105 		setbuffer(iop, buf, 128);
106 		iop->_flag |= _IOLBF|_IOMYBUF;
107 	}
108 	return (0);	/* returns no useful value, keep the same prototype */
109 }
110