xref: /openbsd/lib/libc/stdio/tmpfile.c (revision 09467b48)
1 /*	$OpenBSD: tmpfile.c,v 1.12 2019/04/26 06:33:29 martijn Exp $ */
2 /*-
3  * Copyright (c) 1990, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * This code is derived from software contributed to Berkeley by
7  * Chris Torek.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <unistd.h>
35 #include <signal.h>
36 #include <errno.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <paths.h>
41 
42 FILE *
43 tmpfile(void)
44 {
45 	sigset_t set, oset;
46 	FILE *fp;
47 	int fd, sverrno;
48 	char buf[] = _PATH_TMP "tmp.XXXXXXXXXX";
49 
50 	sigfillset(&set);
51 	(void)sigprocmask(SIG_BLOCK, &set, &oset);
52 
53 	fd = mkstemp(buf);
54 	if (fd != -1)
55 		(void)unlink(buf);
56 
57 	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
58 
59 	if (fd == -1)
60 		return (NULL);
61 
62 	if ((fp = fdopen(fd, "w+")) == NULL) {
63 		sverrno = errno;
64 		(void)close(fd);
65 		errno = sverrno;
66 		return (NULL);
67 	}
68 	return (fp);
69 }
70 DEF_STRONG(tmpfile);
71