stdio-common/tmpfile.c

   1 /* Open a stdio stream on an anonymous temporary file.  Generic/POSIX version.
   2    Copyright (C) 1991,1993,1996-2000,2002,2003,2007,2009
   3    Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <fcntl.h>
  22 #include <stdio.h>
  23 #include <unistd.h>
  24
  25 #ifdef USE_IN_LIBIO
  26 # include <iolibio.h>
  27 # define __fdopen INTUSE(_IO_fdopen)
  28 # ifndef tmpfile
  29 #  define tmpfile __new_tmpfile
  30 # endif
  31 #endif
  32
  33
  34 /* This returns a new stream opened on a temporary file (generated
  35    by tmpnam).  The file is opened with mode "w+b" (binary read/write).
  36    If we couldn't generate a unique filename or the file couldn't
  37    be opened, NULL is returned.  */
  38 FILE *
  39 tmpfile (void)
  40 {
  41   char buf[FILENAME_MAX];
  42   int fd;
  43   FILE *f;
  44
  45   if (__path_search (buf, FILENAME_MAX, NULL, "tmpf", 0))
  46     return NULL;
  47   int flags = 0;
  48 #ifdef FLAGS
  49   flags = FLAGS;
  50 #endif
  51   fd = __gen_tempname (buf, 0, flags, __GT_FILE);
  52   if (fd < 0)
  53     return NULL;
  54
  55   /* Note that this relies on the Unix semantics that
  56      a file is not really removed until it is closed.  */
  57   (void) __unlink (buf);
  58
  59   if ((f = __fdopen (fd, "w+b")) == NULL)
  60     __close (fd);
  61
  62   return f;
  63 }
  64
  65 #if defined USE_IN_LIBIO && !defined FLAGS /* Not for tmpfile64.  */
  66 # undef tmpfile
  67 # include <shlib-compat.h>
  68 versioned_symbol (libc, __new_tmpfile, tmpfile, GLIBC_2_1);
  69 #endif