Imported Upstream version 1.3.9

[debian/gzip] / lib / pipe-safer.c

diff --git a/lib/pipe-safer.c b/lib/pipe-safer.c
new file mode 100644 (file)
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+++ b/lib/pipe-safer.c
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+/* Invoke pipe, but avoid some glitches.
+   Copyright (C) 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 Jim Meyering.  */
+
+#include <config.h>
+
+#include "unistd-safer.h"
+
+#include <unistd.h>
+#include <errno.h>
+
+/* Like pipe, but ensure that neither of the file descriptors is
+   STDIN_FILENO, STDOUT_FILENO, or STDERR_FILENO.  Fail with ENOSYS on
+   platforms that lack pipe.  */
+
+int
+pipe_safer (int fd[2])
+{
+#if HAVE_PIPE
+  if (pipe (fd) == 0)
+    {
+      int i;
+      for (i = 0; i < 2; i++)
+       {
+         fd[i] = fd_safer (fd[i]);
+         if (fd[i] < 0)
+           {
+             int e = errno;
+             close (fd[1 - i]);
+             errno = e;
+             return -1;
+           }
+       }
+
+      return 0;
+    }
+#else
+  errno = ENOSYS;
+#endif
+
+  return -1;
+}