1 files changed, 45 insertions, 0 deletions

diff --git a/gl/dup-safer.c b/gl/dup-safer.c
new file mode 100644
index 00000000..7b12b615
--- /dev/null
+++ b/gl/dup-safer.c
@@ -0,0 +1,45 @@
+/* Invoke dup, but avoid some glitches.
+
+   Copyright (C) 2001, 2004, 2005, 2006 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 2, 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, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Paul Eggert.  */
+
+#include <config.h>
+
+#include "unistd-safer.h"
+
+#include <fcntl.h>
+
+#include <unistd.h>
+#ifndef STDERR_FILENO
+# define STDERR_FILENO 2
+#endif
+
+/* Like dup, but do not return STDIN_FILENO, STDOUT_FILENO, or
+   STDERR_FILENO.  */
+
+int
+dup_safer (int fd)
+{
+#if defined F_DUPFD && !defined FCHDIR_REPLACEMENT
+  return fcntl (fd, F_DUPFD, STDERR_FILENO + 1);
+#else
+  /* fd_safer calls us back, but eventually the recursion unwinds and
+     does the right thing.  */
+  return fd_safer (dup (fd));
+#endif
+}