stdio-common/tempnam.c

   1 /* Copyright (C) 1991-2023 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <stdio.h>
  19 #include <string.h>
  20
  21 /* Generate a unique temporary filename using up to five characters of
  22    PFX if it is not NULL.  The directory to put this file in is
  23    searched for as follows: First the environment variable "TMPDIR" is
  24    checked.  If it contains the name of a directory, that directory is
  25    used.  If not and if DIR is not NULL, that value is checked.  If
  26    that fails, P_tmpdir is tried and finally "/tmp".  The storage for
  27    the filename is allocated by `malloc'.  */
  28 char *
  29 tempnam (const char *dir, const char *pfx)
  30 {
  31   char buf[FILENAME_MAX];
  32
  33   if (__path_search (buf, FILENAME_MAX, dir, pfx, 1))
  34     return NULL;
  35
  36   if (__gen_tempname (buf, 0, 0, __GT_NOCREATE))
  37     return NULL;
  38
  39   return __strdup (buf);
  40 }
  41
  42 link_warning (tempnam,
  43               "the use of `tempnam' is dangerous, better use `mkstemp'")