stdio-common/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    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <stdio.h>
  20 #include <unistd.h>
  21
  22 #ifdef USE_IN_LIBIO
  23 # include <iolibio.h>
  24 # define __fdopen _IO_fdopen
  25 # define tmpfile __new_tmpfile
  26 #endif
  27
  28 /* This returns a new stream opened on a temporary file (generated
  29    by tmpnam).  The file is opened with mode "w+b" (binary read/write).
  30    If we couldn't generate a unique filename or the file couldn't
  31    be opened, NULL is returned.  */
  32 FILE *
  33 tmpfile (void)
  34 {
  35   char buf[FILENAME_MAX];
  36   int fd;
  37   FILE *f;
  38
  39   if (__path_search (buf, FILENAME_MAX, NULL, "tmpf", 0))
  40     return NULL;
  41   fd = __gen_tempname (buf, 1, 0);
  42   if (fd < 0)
  43     return NULL;
  44
  45   /* Note that this relies on the Unix semantics that
  46      a file is not really removed until it is closed.  */
  47   (void) remove (buf);
  48
  49   if ((f = __fdopen (fd, "w+b")) == NULL)
  50     __close (fd);
  51
  52   return f;
  53 }
  54
  55 #ifdef USE_IN_LIBIO
  56 # undef tmpfile
  57 # if defined PIC && DO_VERSIONING
  58 default_symbol_version (__new_tmpfile, tmpfile, GLIBC_2.1);
  59 # else
  60 #  ifdef weak_alias
  61 weak_alias (__new_tmpfile, tmpfile)
  62 #  endif
  63 # endif
  64 #endif