xref: /netbsd-src/lib/libc/stdio/funopen.c (revision 2fa47ecfcb23a9fa15f2448c2ad113946a4b0bf9)
1 /*	$NetBSD: funopen.c,v 1.12 2012/03/15 18:22:30 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Chris Torek.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 #if defined(LIBC_SCCS) && !defined(lint)
37 #if 0
38 static char sccsid[] = "@(#)funopen.c	8.1 (Berkeley) 6/4/93";
39 #else
40 __RCSID("$NetBSD: funopen.c,v 1.12 2012/03/15 18:22:30 christos Exp $");
41 #endif
42 #endif /* LIBC_SCCS and not lint */
43 
44 #include <stdio.h>
45 #include <errno.h>
46 #include "reentrant.h"
47 #include "local.h"
48 
49 FILE *
50 funopen(const void *cookie,
51     int (*readfn)(void *, char *, int),
52     int (*writefn)(void *, const char *, int),
53     off_t (*seekfn)(void *, off_t, int),
54     int (*closefn)(void *))
55 {
56 	FILE *fp;
57 	int flags;
58 
59 	if (readfn == NULL) {
60 		if (writefn == NULL) {		/* illegal */
61 			errno = EINVAL;
62 			return NULL;
63 		} else
64 			flags = __SWR;		/* write only */
65 	} else {
66 		if (writefn == NULL)
67 			flags = __SRD;		/* read only */
68 		else
69 			flags = __SRW;		/* read-write */
70 	}
71 	if ((fp = __sfp()) == NULL)
72 		return NULL;
73 	fp->_flags = flags;
74 	fp->_file = -1;
75 	fp->_cookie = __UNCONST(cookie);
76 	fp->_read = readfn;
77 	fp->_write = writefn;
78 	fp->_seek = seekfn;
79 	fp->_close = closefn;
80 	return fp;
81 }
82