xref: /freebsd/lib/libc/stdio/funopen.c (revision f5463265955b829775bbb32e1fd0bc11dafc36ce)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 <stdio.h>
36 #include <errno.h>
37 
38 #include "local.h"
39 
40 FILE *
41 funopen(const void *cookie,
42 	int (*readfn)(void *, char *, int),
43 	int (*writefn)(void *, const char *, int),
44 	fpos_t (*seekfn)(void *, fpos_t, int),
45 	int (*closefn)(void *))
46 {
47 	FILE *fp;
48 	int flags;
49 
50 	if (readfn == NULL) {
51 		if (writefn == NULL) {		/* illegal */
52 			errno = EINVAL;
53 			return (NULL);
54 		} else
55 			flags = __SWR;		/* write only */
56 	} else {
57 		if (writefn == NULL)
58 			flags = __SRD;		/* read only */
59 		else
60 			flags = __SRW;		/* read-write */
61 	}
62 	if ((fp = __sfp()) == NULL)
63 		return (NULL);
64 	fp->_flags = flags;
65 	fp->_file = -1;
66 	fp->_cookie = (void *)cookie;
67 	fp->_read = readfn;
68 	fp->_write = writefn;
69 	fp->_seek = seekfn;
70 	fp->_close = closefn;
71 	return (fp);
72 }
73