libc/stdio/tmpfile.c

   1 /* Copyright (C) 1991, 1993, 1996, 1997, 1998 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 <features.h>
  19 #include <stdio.h>
  20 #include <sys/stat.h>
  21 #include <unistd.h>
  22 #include "../misc/internals/tempname.h"
  23 #include <not-cancel.h>
  24
  25
  26 /* This returns a new stream opened on a temporary file (generated
  27    by tmpnam).  The file is opened with mode "w+b" (binary read/write).
  28    If we couldn't generate a unique filename or the file couldn't
  29    be opened, NULL is returned.  */
  30 FILE * tmpfile (void)
  31 {
  32     char buf[FILENAME_MAX];
  33     int fd;
  34     FILE *f;
  35
  36     if (__path_search (buf, FILENAME_MAX, NULL, "tmpf", 0))
  37         return NULL;
  38     fd = __gen_tempname (buf, __GT_FILE, 0, 0, S_IRUSR | S_IWUSR);
  39     if (fd < 0)
  40         return NULL;
  41
  42     /* Note that this relies on the Unix semantics that
  43        a file is not really removed until it is closed.  */
  44     (void) remove (buf);
  45
  46     if ((f = fdopen (fd, "w+b")) == NULL)
  47         close_not_cancel (fd);
  48
  49     return f;
  50 }
  51 strong_alias(tmpfile,tmpfile64)