libc/stdio/tempnam.c

   1 /* Copyright (C) 1991,1993,1996-1999,2000 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 Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    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    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    see <http://www.gnu.org/licenses/>.  */
  17
  18 #include <stdio.h>
  19 #include <string.h>
  20 #include "../misc/internals/tempname.h"
  21
  22
  23 /* Generate a unique temporary filename using up to five characters of PFX
  24    if it is not NULL.  The directory to put this file in is searched for
  25    as follows: First the environment variable "TMPDIR" is checked.
  26    If it contains the name of a writable directory, that directory is used.
  27    If not and if DIR is not NULL, that value is checked.  If that fails,
  28    P_tmpdir is tried and finally "/tmp".  The storage for the filename
  29    is allocated by `malloc'.  */
  30 char *
  31 tempnam (const char *dir, const char *pfx)
  32 {
  33   char buf[FILENAME_MAX];
  34
  35   if (__path_search (buf, FILENAME_MAX, dir, pfx, 1))
  36     return NULL;
  37
  38   if (__gen_tempname (buf, __GT_NOCREATE, 0, 0, 0))
  39     return NULL;
  40
  41   return strdup (buf);
  42 }