view lib/unlinkdir.c @ 12246:b156d2d1b827

freopen-safer: new module * modules/freopen-safer: New module. * m4/stdio-safer.m4 (gl_FREOPEN_SAFER): New macro. * lib/freopen-safer.c (freopen_safer): New file. * lib/stdio-safer.h (freopen_safer): New declaration. * lib/stdio--.h (freopen): New override. * MODULES.html.sh (File stream based Input/Output): Mention it. * doc/posix-functions/freopen.texi (freopen): Mention pitfalls and freopen-safer module. * doc/posix-functions/stderr.texi (stderr): Likewise. * doc/posix-functions/stdin.texi (stdin): Likewise. * doc/posix-functions/stdout.texi (stdout): Likewise. * modules/freopen-safer-tests: New test. * tests/test-reopen-safer.c: New file. Signed-off-by: Eric Blake <ebb9@byu.net>
author Eric Blake <ebb9@byu.net>
date Thu, 05 Nov 2009 15:13:00 -0700
parents af683213eeb0
children e8d2c6fc33ad
line wrap: on
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/* unlinkdir.c - determine whether we can unlink directories

   Copyright (C) 2005-2006, 2009 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/* Written by Paul Eggert, Jim Meyering, and David Bartley.  */

#include <config.h>

#include "unlinkdir.h"
#include "priv-set.h"
#include <unistd.h>

#if ! UNLINK_CANNOT_UNLINK_DIR

/* Return true if we cannot unlink directories, false if we might be
   able to unlink directories.  */

bool
cannot_unlink_dir (void)
{
  static bool initialized;
  static bool cannot;

  if (! initialized)
    {
# if defined PRIV_SYS_LINKDIR
      /* We might be able to unlink directories if we cannot
	 determine our privileges, or if we have the
	 PRIV_SYS_LINKDIR privilege.  */
      cannot = (priv_set_ismember (PRIV_SYS_LINKDIR) == 0);
# else
      /* In traditional Unix, only root can unlink directories.  */
      cannot = (geteuid () != 0);
# endif
      initialized = true;
    }

  return cannot;
}

#endif