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-rw-r--r--lib/dup-safer.c59
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diff --git a/lib/dup-safer.c b/lib/dup-safer.c
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+/* Invoke dup, but avoid some glitches.
+ Copyright (C) 2001, 2004 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+
+/* Written by Paul Eggert. */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <errno.h>
+
+#if HAVE_FCNTL_H
+# include <fcntl.h>
+#endif
+
+#if HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+#ifndef STDERR_FILENO
+# define STDERR_FILENO 2
+#endif
+
+#include <unistd-safer.h>
+
+/* Like dup, but do not return STDIN_FILENO, STDOUT_FILENO, or
+ STDERR_FILENO. */
+
+int
+dup_safer (int fd)
+{
+#ifdef F_DUPFD
+ return fcntl (fd, F_DUPFD, STDERR_FILENO + 1);
+#else
+ int f = dup (fd);
+ if (0 <= f && f <= STDERR_FILENO)
+ {
+ int f1 = dup_safer (f);
+ int e = errno;
+ close (f);
+ errno = e;
+ f = f1;
+ }
+ return f;
+#endif
+}