xref: /illumos-gate/usr/src/lib/libc/port/stdio/tmpnam_r.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T */
28 /*	  All Rights Reserved	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include "lint.h"
33 #include "mtlib.h"
34 #include <sys/types.h>
35 #include <stdio.h>
36 #include <string.h>
37 #include <stdlib.h>
38 #include <errno.h>
39 #include <thread.h>
40 #include <synch.h>
41 #include "tsd.h"
42 
43 static char seed[] = { 'a', 'a', 'a', '\0' };
44 
45 static mutex_t seed_lk = DEFAULTMUTEX;
46 
47 char *
48 tmpnam_r(char *s)
49 {
50 	char *p = s, *q;
51 
52 	if (!s)
53 		return (NULL);
54 
55 	(void) strcpy(p, P_tmpdir);
56 	lmutex_lock(&seed_lk);
57 	(void) strcat(p, seed);
58 	(void) strcat(p, "XXXXXX");
59 
60 	q = seed;
61 	while (*q == 'z')
62 		*q++ = 'a';
63 	if (*q != '\0')
64 		++*q;
65 	lmutex_unlock(&seed_lk);
66 	(void) mktemp(p);
67 	return (p);
68 }
69 
70 char *
71 tmpnam(char *s)
72 {
73 	if (s == NULL)
74 		s = tsdalloc(_T_TMPNAM, L_tmpnam, NULL);
75 	return (tmpnam_r(s));
76 }
77