sysdeps/generic/tmpfile.c

   1 /* Open a stdio stream on an anonymous temporary file.  Generic/POSIX version.
   2    Copyright (C) 1991,93,96,97,98,99,2000,2002 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <stdio.h>
  21 #include <unistd.h>
  22
  23 #ifdef USE_IN_LIBIO
  24 # include <iolibio.h>
  25 # define __fdopen INTUSE(_IO_fdopen)
  26 # define tmpfile __new_tmpfile
  27 #endif
  28
  29 /* This returns a new stream opened on a temporary file (generated
  30    by tmpnam).  The file is opened with mode "w+b" (binary read/write).
  31    If we couldn't generate a unique filename or the file couldn't
  32    be opened, NULL is returned.  */
  33 FILE *
  34 tmpfile (void)
  35 {
  36   char buf[FILENAME_MAX];
  37   int fd;
  38   FILE *f;
  39
  40   if (__path_search (buf, FILENAME_MAX, NULL, "tmpf", 0))
  41     return NULL;
  42   fd = __gen_tempname (buf, __GT_FILE);
  43   if (fd < 0)
  44     return NULL;
  45
  46   /* Note that this relies on the Unix semantics that
  47      a file is not really removed until it is closed.  */
  48   (void) remove (buf);
  49
  50   if ((f = __fdopen (fd, "w+b")) == NULL)
  51     __close (fd);
  52
  53   return f;
  54 }
  55
  56 #ifdef USE_IN_LIBIO
  57 # undef tmpfile
  58 # include <shlib-compat.h>
  59 versioned_symbol (libc, __new_tmpfile, tmpfile, GLIBC_2_1);
  60 #endif