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[gnulib.git] / lib / dup2.c

diff --git a/lib/dup2.c b/lib/dup2.c
index 77deaf6..6d61829 100644 (file)
--- a/lib/dup2.c
+++ b/lib/dup2.c
@@ -1,10 +1,12 @@
 /* Duplicate an open file descriptor to a specified file descriptor.
-   Copyright (C) 1999, 2004 Free Software Foundation, Inc.
 
-   This program is free software; you can redistribute it and/or modify
+   Copyright (C) 1999, 2004, 2005, 2006, 2007, 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 2, or (at your option)
-   any later version.
+   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
@@ -12,24 +14,57 @@
    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.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 /* written by Paul Eggert */
 
-#if HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include <config.h>
 
-#include <errno.h>
+/* Specification.  */
+#include <unistd.h>
 
+#include <errno.h>
 #include <fcntl.h>
 
-#if HAVE_UNISTD_H
-# include <unistd.h>
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Get declarations of the Win32 API functions.  */
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
 #endif
 
-#ifndef F_DUPFD
+#if REPLACE_DUP2
+
+# undef dup2
+
+int
+rpl_dup2 (int fd, int desired_fd)
+{
+  int result;
+# if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+  /* If fd is closed, mingw hangs on dup2 (fd, fd).  If fd is open,
+     dup2 (fd, fd) returns 0, but all further attempts to use fd in
+     future dup2 calls will hang.  */
+  if (fd == desired_fd)
+    {
+      if ((HANDLE) _get_osfhandle (fd) == INVALID_HANDLE_VALUE)
+        {
+          errno = EBADF;
+          return -1;
+        }
+      return fd;
+    }
+# endif
+  result = dup2 (fd, desired_fd);
+  if (result == 0)
+    result = desired_fd;
+  return result;
+}
+
+#else /* !REPLACE_DUP2 */
+
+/* On older platforms, dup2 did not exist.  */
+
+# ifndef F_DUPFD
 static int
 dupfd (int fd, int desired_fd)
 {
@@ -45,7 +80,7 @@ dupfd (int fd, int desired_fd)
       return r;
     }
 }
-#endif
+# endif
 
 int
 dup2 (int fd, int desired_fd)
@@ -53,9 +88,10 @@ dup2 (int fd, int desired_fd)
   if (fd == desired_fd)
     return fd;
   close (desired_fd);
-#ifdef F_DUPFD
+# ifdef F_DUPFD
   return fcntl (fd, F_DUPFD, desired_fd);
-#else
+# else
   return dupfd (fd, desired_fd);
-#endif
+# endif
 }
+#endif /* !REPLACE_DUP2 */