compat_mkdtemp.c

   1 #include "config.h"
   2
   3 #if HAVE_MKDTEMP
   4
   5 int dummy;
   6
   7 #else
   8
   9 /*      $Id: compat_mkdtemp.c,v 1.2 2015/10/06 18:32:19 schwarze Exp $  */
  10 /*
  11  * Copyright (c) 2015 Ingo Schwarze <schwarze@openbsd.org>
  12  *
  13  * Permission to use, copy, modify, and distribute this software for any
  14  * purpose with or without fee is hereby granted, provided that the above
  15  * copyright notice and this permission notice appear in all copies.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  18  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  20  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  21  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  22  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  23  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  24  *
  25  * The algorithm of this function is inspired by OpenBSD mkdtemp(3)
  26  * by Theo de Raadt and Todd Miller, but the code differs.
  27  */
  28
  29 #include <sys/stat.h>
  30 #include <errno.h>
  31 #include <limits.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34
  35 char *
  36 mkdtemp(char *path)
  37 {
  38         char            *start, *cp;
  39         unsigned         int tries;
  40
  41         start = strchr(path, '\0');
  42         while (start > path && start[-1] == 'X')
  43                 start--;
  44
  45         for (tries = INT_MAX; tries; tries--) {
  46                 if (mktemp(path) == NULL) {
  47                         errno = EEXIST;
  48                         return NULL;
  49                 }
  50                 if (mkdir(path, S_IRUSR | S_IWUSR | S_IXUSR) == 0)
  51                         return path;
  52                 if (errno != EEXIST)
  53                         return NULL;
  54                 for (cp = start; *cp != '\0'; cp++)
  55                         *cp = 'X';
  56         }
  57         errno = EEXIST;
  58         return NULL;
  59 }
  60
  61 #endif