xref: /freebsd/lib/libc/stdio/tempnam.c (revision 0b3105a37d7adcadcb720112fed4dc4e8040be99)
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  * 3. 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(const char *dir, const char *pfx)
51 {
52 	int sverrno;
53 	char *f, *name;
54 
55 	if (!(name = malloc(MAXPATHLEN)))
56 		return(NULL);
57 
58 	if (!pfx)
59 		pfx = "tmp.";
60 
61 	if (issetugid() == 0 && (f = getenv("TMPDIR"))) {
62 		(void)snprintf(name, MAXPATHLEN, "%s%s%sXXXXXX", f,
63 		    *(f + strlen(f) - 1) == '/'? "": "/", pfx);
64 		if ((f = _mktemp(name)))
65 			return(f);
66 	}
67 
68 	if ((f = (char *)dir)) {
69 		(void)snprintf(name, MAXPATHLEN, "%s%s%sXXXXXX", f,
70 		    *(f + strlen(f) - 1) == '/'? "": "/", pfx);
71 		if ((f = _mktemp(name)))
72 			return(f);
73 	}
74 
75 	f = P_tmpdir;
76 	(void)snprintf(name, MAXPATHLEN, "%s%sXXXXXX", f, pfx);
77 	if ((f = _mktemp(name)))
78 		return(f);
79 
80 	f = _PATH_TMP;
81 	(void)snprintf(name, MAXPATHLEN, "%s%sXXXXXX", f, pfx);
82 	if ((f = _mktemp(name)))
83 		return(f);
84 
85 	sverrno = errno;
86 	free(name);
87 	errno = sverrno;
88 	return(NULL);
89 }
90