1/*	$NetBSD: tempnam.c,v 1.21 2009/10/25 20:44:13 christos Exp $	*/
2
3/*
4 * Copyright (c) 1988, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#if defined(LIBC_SCCS) && !defined(lint)
34#if 0
35static char sccsid[] = "@(#)tempnam.c	8.1 (Berkeley) 6/4/93";
36#else
37__RCSID("$NetBSD: tempnam.c,v 1.21 2009/10/25 20:44:13 christos Exp $");
38#endif
39#endif /* LIBC_SCCS and not lint */
40
41#include "namespace.h"
42#include <sys/param.h>
43#include <errno.h>
44#include <stdio.h>
45#include <stdlib.h>
46#include <string.h>
47#include <unistd.h>
48#include <paths.h>
49#include "reentrant.h"
50#include "local.h"
51
52__warn_references(tempnam,
53    "warning: tempnam() possibly used unsafely, use mkstemp() or mkdtemp()")
54
55static const char *
56trailsl(const char *f)
57{
58	const char *s = f;
59	while (*s)
60		s++;
61	return (f != s && s[-1] == '/') ? "" : "/";
62}
63
64static char *
65gentemp(char *name, size_t len, const char *tmp, const char  *pfx)
66{
67	(void)snprintf(name, len, "%s%s%sXXXXXXXXXX", tmp, trailsl(tmp), pfx);
68	return _mktemp(name);
69}
70
71char *
72tempnam(const char *dir, const char *pfx)
73{
74	int sverrno;
75	char *name, *f;
76	const char *tmp;
77
78	if (!(name = malloc((size_t)MAXPATHLEN)))
79		return NULL;
80
81	if (!pfx)
82		pfx = "tmp.";
83
84	if ((tmp = getenv("TMPDIR")) != NULL &&
85	    (f = gentemp(name, (size_t)MAXPATHLEN, tmp, pfx)) != NULL)
86		return f;
87
88	if (dir != NULL &&
89	    (f = gentemp(name, (size_t)MAXPATHLEN, dir, pfx)) != NULL)
90		return f;
91
92	if ((f = gentemp(name, (size_t)MAXPATHLEN, P_tmpdir, pfx)) != NULL)
93		return f;
94
95	if ((f = gentemp(name, (size_t)MAXPATHLEN, _PATH_TMP, pfx)) != NULL)
96		return f;
97
98	sverrno = errno;
99	free(name);
100	errno = sverrno;
101	return NULL;
102}
103