xref: /freebsd/lib/libc/stdio/tempnam.c (revision 6780ab54325a71e7e70112b11657973edde8655e)
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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)tempnam.c	8.1 (Berkeley) 6/4/93";
36 #endif /* LIBC_SCCS and not lint */
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <sys/param.h>
41 #include <errno.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 #include <paths.h>
47 
48 __warn_references(tempnam,
49     "warning: tempnam() possibly used unsafely; consider using mkstemp()");
50 
51 extern char *_mktemp(char *);
52 
53 char *
54 tempnam(dir, pfx)
55 	const char *dir, *pfx;
56 {
57 	int sverrno;
58 	char *f, *name;
59 
60 	if (!(name = malloc(MAXPATHLEN)))
61 		return(NULL);
62 
63 	if (!pfx)
64 		pfx = "tmp.";
65 
66 	if (issetugid() == 0 && (f = getenv("TMPDIR"))) {
67 		(void)snprintf(name, MAXPATHLEN, "%s%s%sXXXXXX", f,
68 		    *(f + strlen(f) - 1) == '/'? "": "/", pfx);
69 		if ((f = _mktemp(name)))
70 			return(f);
71 	}
72 
73 	if ((f = (char *)dir)) {
74 		(void)snprintf(name, MAXPATHLEN, "%s%s%sXXXXXX", f,
75 		    *(f + strlen(f) - 1) == '/'? "": "/", pfx);
76 		if ((f = _mktemp(name)))
77 			return(f);
78 	}
79 
80 	f = P_tmpdir;
81 	(void)snprintf(name, MAXPATHLEN, "%s%sXXXXXX", f, pfx);
82 	if ((f = _mktemp(name)))
83 		return(f);
84 
85 	f = _PATH_TMP;
86 	(void)snprintf(name, MAXPATHLEN, "%s%sXXXXXX", f, pfx);
87 	if ((f = _mktemp(name)))
88 		return(f);
89 
90 	sverrno = errno;
91 	free(name);
92 	errno = sverrno;
93 	return(NULL);
94 }
95