stdio-common/tmpfile.c

   1 /* Open a stdio stream on an anonymous temporary file.  Generic/POSIX version.
   2    Copyright (C) 1991,1993,1996-2000,2002,2003,2007,2009,2011
   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 #include <iolibio.h>
  26 #define __fdopen INTUSE(_IO_fdopen)
  27 #ifndef tmpfile
  28 # define tmpfile __new_tmpfile
  29 #endif
  30
  31
  32 /* This returns a new stream opened on a temporary file (generated
  33    by tmpnam).  The file is opened with mode "w+b" (binary read/write).
  34    If we couldn't generate a unique filename or the file couldn't
  35    be opened, NULL is returned.  */
  36 FILE *
  37 tmpfile (void)
  38 {
  39   char buf[FILENAME_MAX];
  40   int fd;
  41   FILE *f;
  42
  43   if (__path_search (buf, FILENAME_MAX, NULL, "tmpf", 0))
  44     return NULL;
  45   int flags = 0;
  46 #ifdef FLAGS
  47   flags = FLAGS;
  48 #endif
  49   fd = __gen_tempname (buf, 0, flags, __GT_FILE);
  50   if (fd < 0)
  51     return NULL;
  52
  53   /* Note that this relies on the Unix semantics that
  54      a file is not really removed until it is closed.  */
  55   (void) __unlink (buf);
  56
  57   if ((f = __fdopen (fd, "w+b")) == NULL)
  58     __close (fd);
  59
  60   return f;
  61 }
  62
  63 #ifndef FLAGS /* Not for tmpfile64.  */
  64 # undef tmpfile
  65 # include <shlib-compat.h>
  66 versioned_symbol (libc, __new_tmpfile, tmpfile, GLIBC_2_1);
  67 #endif