xref: /freebsd/lib/libc/stdio/funopen.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
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 #if defined(LIBC_SCCS) && !defined(lint)
36 static char sccsid[] = "@(#)funopen.c	8.1 (Berkeley) 6/4/93";
37 #endif /* LIBC_SCCS and not lint */
38 #include <sys/cdefs.h>
39 #include <stdio.h>
40 #include <errno.h>
41 
42 #include "local.h"
43 
44 FILE *
45 funopen(const void *cookie,
46 	int (*readfn)(void *, char *, int),
47 	int (*writefn)(void *, const char *, int),
48 	fpos_t (*seekfn)(void *, fpos_t, int),
49 	int (*closefn)(void *))
50 {
51 	FILE *fp;
52 	int flags;
53 
54 	if (readfn == NULL) {
55 		if (writefn == NULL) {		/* illegal */
56 			errno = EINVAL;
57 			return (NULL);
58 		} else
59 			flags = __SWR;		/* write only */
60 	} else {
61 		if (writefn == NULL)
62 			flags = __SRD;		/* read only */
63 		else
64 			flags = __SRW;		/* read-write */
65 	}
66 	if ((fp = __sfp()) == NULL)
67 		return (NULL);
68 	fp->_flags = flags;
69 	fp->_file = -1;
70 	fp->_cookie = (void *)cookie;
71 	fp->_read = readfn;
72 	fp->_write = writefn;
73 	fp->_seek = seekfn;
74 	fp->_close = closefn;
75 	return (fp);
76 }
77