xref: /freebsd/lib/libc/stdio/tempnam.c (revision a10cee30c94cf5944826d2a495e9cdf339dfbcc8)
1  /*
2   * Copyright (c) 1988, 1993
3   *	The Regents of the University of California.  All rights reserved.
4   *
5   * Redistribution and use in source and binary forms, with or without
6   * modification, are permitted provided that the following conditions
7   * are met:
8   * 1. Redistributions of source code must retain the above copyright
9   *    notice, this list of conditions and the following disclaimer.
10   * 2. Redistributions in binary form must reproduce the above copyright
11   *    notice, this list of conditions and the following disclaimer in the
12   *    documentation and/or other materials provided with the distribution.
13   * 4. Neither the name of the University nor the names of its contributors
14   *    may be used to endorse or promote products derived from this software
15   *    without specific prior written permission.
16   *
17   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27   * SUCH DAMAGE.
28   */
29  
30  #if defined(LIBC_SCCS) && !defined(lint)
31  static char sccsid[] = "@(#)tempnam.c	8.1 (Berkeley) 6/4/93";
32  #endif /* LIBC_SCCS and not lint */
33  #include <sys/cdefs.h>
34  __FBSDID("$FreeBSD$");
35  
36  #include <sys/param.h>
37  #include <errno.h>
38  #include <stdio.h>
39  #include <stdlib.h>
40  #include <string.h>
41  #include <unistd.h>
42  #include <paths.h>
43  
44  __warn_references(tempnam,
45      "warning: tempnam() possibly used unsafely; consider using mkstemp()");
46  
47  extern char *_mktemp(char *);
48  
49  char *
50  tempnam(dir, pfx)
51  	const char *dir, *pfx;
52  {
53  	int sverrno;
54  	char *f, *name;
55  
56  	if (!(name = malloc(MAXPATHLEN)))
57  		return(NULL);
58  
59  	if (!pfx)
60  		pfx = "tmp.";
61  
62  	if (issetugid() == 0 && (f = getenv("TMPDIR"))) {
63  		(void)snprintf(name, MAXPATHLEN, "%s%s%sXXXXXX", f,
64  		    *(f + strlen(f) - 1) == '/'? "": "/", pfx);
65  		if ((f = _mktemp(name)))
66  			return(f);
67  	}
68  
69  	if ((f = (char *)dir)) {
70  		(void)snprintf(name, MAXPATHLEN, "%s%s%sXXXXXX", f,
71  		    *(f + strlen(f) - 1) == '/'? "": "/", pfx);
72  		if ((f = _mktemp(name)))
73  			return(f);
74  	}
75  
76  	f = P_tmpdir;
77  	(void)snprintf(name, MAXPATHLEN, "%s%sXXXXXX", f, pfx);
78  	if ((f = _mktemp(name)))
79  		return(f);
80  
81  	f = _PATH_TMP;
82  	(void)snprintf(name, MAXPATHLEN, "%s%sXXXXXX", f, pfx);
83  	if ((f = _mktemp(name)))
84  		return(f);
85  
86  	sverrno = errno;
87  	free(name);
88  	errno = sverrno;
89  	return(NULL);
90  }
91