/* Duplicate an open file descriptor to a specified file descriptor.
- Copyright (C) 1999, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+ 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
#include <errno.h>
#include <fcntl.h>
-#ifndef F_DUPFD
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Get declarations of the Win32 API functions. */
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+#endif
+
+#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);
+# ifdef __linux__
+ /* Correct a Linux return value.
+ <http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.30.y.git;a=commitdiff;h=2b79bc4f7ebbd5af3c8b867968f9f15602d5f802>
+ */
+ if (fd == desired_fd && result == (unsigned int) -EBADF)
+ {
+ errno = EBADF;
+ result = -1;
+ }
+# endif
+ if (result == 0)
+ result = desired_fd;
+ /* Correct a cygwin 1.5.x errno value. */
+ else if (result == -1 && errno == EMFILE)
+ errno = EBADF;
+#if REPLACE_FCHDIR
+ if (fd != desired_fd && result == desired_fd)
+ result = _gl_register_dup (fd, desired_fd);
+#endif
+ return result;
+}
+
+#else /* !REPLACE_DUP2 */
+
+/* On older platforms, dup2 did not exist. */
+
+# ifndef F_DUPFD
static int
dupfd (int fd, int desired_fd)
{
return r;
}
}
-#endif
+# endif
int
dup2 (int fd, int desired_fd)
{
+ int result;
if (fd == desired_fd)
- return fd;
+ return fcntl (fd, F_GETFL) < 0 ? -1 : fd;
close (desired_fd);
-#ifdef F_DUPFD
- return fcntl (fd, F_DUPFD, desired_fd);
-#else
- return dupfd (fd, desired_fd);
+# ifdef F_DUPFD
+ result = fcntl (fd, F_DUPFD, desired_fd);
+# else
+ result = dupfd (fd, desired_fd);
+# endif
+#if REPLACE_FCHDIR
+ if (0 <= result)
+ result = _gl_register_dup (fd, desired_fd);
#endif
+ return result;
}
+#endif /* !REPLACE_DUP2 */