xref: /netbsd/lib/libc/stdio/tmpfile.c (revision c4a72b64)
1 /*	$NetBSD: tmpfile.c,v 1.9 2002/08/10 16:28:51 yamt 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. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #if defined(LIBC_SCCS) && !defined(lint)
41 #if 0
42 static char sccsid[] = "@(#)tmpfile.c	8.1 (Berkeley) 6/4/93";
43 #else
44 __RCSID("$NetBSD: tmpfile.c,v 1.9 2002/08/10 16:28:51 yamt Exp $");
45 #endif
46 #endif /* LIBC_SCCS and not lint */
47 
48 #include "namespace.h"
49 #include <sys/types.h>
50 #include <unistd.h>
51 #include <signal.h>
52 #include <errno.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <paths.h>
57 
58 FILE *
59 tmpfile()
60 {
61 	sigset_t set, oset;
62 	FILE *fp;
63 	int fd, sverrno;
64 #define	TRAILER	"tmp.XXXXXXXXXX"
65 	char buf[sizeof(_PATH_TMP) + sizeof(TRAILER)];
66 
67 	(void)memcpy(buf, _PATH_TMP, sizeof(_PATH_TMP) - 1);
68 	(void)memcpy(buf + sizeof(_PATH_TMP) - 1, TRAILER, sizeof(TRAILER));
69 
70 	sigfillset(&set);
71 	(void)sigprocmask(SIG_BLOCK, &set, &oset);
72 
73 	fd = mkstemp(buf);
74 	if (fd != -1)
75 		(void)unlink(buf);
76 
77 	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
78 
79 	if (fd == -1)
80 		return (NULL);
81 
82 	if ((fp = fdopen(fd, "w+")) == NULL) {
83 		sverrno = errno;
84 		(void)close(fd);
85 		errno = sverrno;
86 		return (NULL);
87 	}
88 	return (fp);
89 }
90