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authorAndreas Rottmann <a.rottmann@gmx.at>2009-09-14 12:34:39 +0200
committerAndreas Rottmann <a.rottmann@gmx.at>2009-09-14 12:34:39 +0200
commit79ca645d222db2e158784642c3b464a47bea26f3 (patch)
tree73fa0e7f2f509013ca7ea3395b268c8471b2355b /lib/dup2.c
parent8a927bfd7da41dbe61f3cfeaccbd37c761c0bc36 (diff)
parent3bebb94360f1c2333feb8d504a9fa4f96984d8b7 (diff)
Merge commit 'upstream/0.9.1.1'
Diffstat (limited to 'lib/dup2.c')
-rw-r--r--lib/dup2.c97
1 files changed, 97 insertions, 0 deletions
diff --git a/lib/dup2.c b/lib/dup2.c
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+++ b/lib/dup2.c
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+/* Duplicate an open file descriptor to a specified file descriptor.
+
+ 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 Lesser 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 Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+/* written by Paul Eggert */
+
+#include <config.h>
+
+/* Specification. */
+#include <unistd.h>
+
+#include <errno.h>
+#include <fcntl.h>
+
+#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);
+ 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)
+{
+ int duplicated_fd = dup (fd);
+ if (duplicated_fd < 0 || duplicated_fd == desired_fd)
+ return duplicated_fd;
+ else
+ {
+ int r = dupfd (fd, desired_fd);
+ int e = errno;
+ close (duplicated_fd);
+ errno = e;
+ return r;
+ }
+}
+# endif
+
+int
+dup2 (int fd, int desired_fd)
+{
+ if (fd == desired_fd)
+ return fd;
+ close (desired_fd);
+# ifdef F_DUPFD
+ return fcntl (fd, F_DUPFD, desired_fd);
+# else
+ return dupfd (fd, desired_fd);
+# endif
+}
+#endif /* !REPLACE_DUP2 */