tempnam.c

绝对正真的stdio.h的实现

/* Copyright (C) 1991,1993,1996-1999,2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <stdio.h>
#include <string.h>

/* Generate a unique temporary filename using up to five characters of PFX
   if it is not NULL.  The directory to put this file in is searched for
   as follows: First the environment variable "TMPDIR" is checked.
   If it contains the name of a writable directory, that directory is used.
   If not and if DIR is not NULL, that value is checked.  If that fails,
   P_tmpdir is tried and finally "/tmp".  The storage for the filename
   is allocated by `malloc'.  */
char *
tempnam (const char *dir, const char *pfx)
{
  char buf[FILENAME_MAX];

  if (__path_search (buf, FILENAME_MAX, dir, pfx, 1))
    return NULL;

  if (__gen_tempname (buf, __GT_NOCREATE))
    return NULL;

  return __strdup (buf);
}

link_warning (tempnam,
	      "the use of `tempnam' is dangerous, better use `mkstemp'")