1 files changed, 50 insertions, 0 deletions
diff --git a/src/grep/lib/dup-safer.c b/src/grep/lib/dup-safer.c
new file mode 100644
index 0000000..d8d3de3
--- /dev/null
+++ b/src/grep/lib/dup-safer.c
@@ -0,0 +1,50 @@
+/* Invoke dup, but avoid some glitches.
+
+   Copyright (C) 2001, 2004-2006, 2009-2021 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 <https://www.gnu.org/licenses/>.  */
+
+/* Written by Paul Eggert.  */
+
+#include <config.h>
+
+#include "unistd-safer.h"
+
+#include <fcntl.h>
+#include <unistd.h>
+
+/* Like dup, but do not return STDIN_FILENO, STDOUT_FILENO, or
+   STDERR_FILENO.  */
+
+int
+dup_safer (int fd)
+{
+#if defined(KMK_GREP) && defined(_MSC_VER)
+  int afd[STDERR_FILENO + 1];
+  int i;
+  for (i = 0; ; i++)
+    {
+      int fdNew = _dup(fd);
+      if (fdNew >= STDERR_FILENO + 1 || fdNew < 0)
+        {
+          while (i-- > 0)
+            close(afd[i]);
+          return fdNew;
+        }
+      afd[i] = fdNew;
+    }
+#else
+  return fcntl (fd, F_DUPFD, STDERR_FILENO + 1);
+#endif
+}