tmpfile.c revision 110429 
1/*-
2 * Copyright (c) 1990, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Chris Torek.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#if defined(LIBC_SCCS) && !defined(lint)
38static char sccsid[] = "@(#)tmpfile.c	8.1 (Berkeley) 6/4/93";
39#endif /* LIBC_SCCS and not lint */
40#include <sys/cdefs.h>
41__FBSDID("$FreeBSD: head/lib/libc/stdio/tmpfile.c 110429 2003-02-06 01:08:19Z mtm $");
42
43#include "namespace.h"
44#include <sys/types.h>
45#include <signal.h>
46#include <unistd.h>
47#include <errno.h>
48#include <stdio.h>
49#include <stdlib.h>
50#include <string.h>
51#include <paths.h>
52#include "un-namespace.h"
53
54FILE *
55tmpfile()
56{
57	sigset_t set, oset;
58	FILE *fp;
59	int fd, sverrno;
60#define	TRAILER	"tmp.XXXXXX"
61	char *buf;
62	const char *tmpdir;
63
64	tmpdir = NULL;
65	if (issetugid() == 0)
66		tmpdir = getenv("TMPDIR");
67	if (tmpdir == NULL)
68		tmpdir = _PATH_TMP;
69
70	(void)asprintf(&buf, "%s%s%s", tmpdir,
71	    (tmpdir[strlen(tmpdir) - 1] == '/') ? "" : "/", TRAILER);
72	if (buf == NULL)
73		return (NULL);
74
75	sigfillset(&set);
76	(void)_sigprocmask(SIG_BLOCK, &set, &oset);
77
78	fd = mkstemp(buf);
79	if (fd != -1)
80		(void)unlink(buf);
81
82	free(buf);
83
84	(void)_sigprocmask(SIG_SETMASK, &oset, NULL);
85
86	if (fd == -1)
87		return (NULL);
88
89	if ((fp = fdopen(fd, "w+")) == NULL) {
90		sverrno = errno;
91		(void)_close(fd);
92		errno = sverrno;
93		return (NULL);
94	}
95	return (fp);
96}
97