xref: /illumos-gate/usr/src/ucblib/libucb/port/gen/setbuffer.c (revision fd6d41c5025e9fb45a115fc82d86e9983d1e9fd6)
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 }
105