lib/libc/stdio/tempnam.c

   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 }