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      1 /*	$NetBSD: tempnam.c,v 1.22 2012/03/15 18:22:30 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
     35 static char sccsid[] = "@(#)tempnam.c	8.1 (Berkeley) 6/4/93";
     36 #else
     37 __RCSID("$NetBSD: tempnam.c,v 1.22 2012/03/15 18:22:30 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 
     55 static const char *
     56 trailsl(const char *f)
     57 {
     58 	const char *s = f;
     59 	while (*s)
     60 		s++;
     61 	return (f != s && s[-1] == '/') ? "" : "/";
     62 }
     63 
     64 static char *
     65 gentemp(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 
     71 char *
     72 tempnam(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