added tag v1_9_0_4

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/tags/v1_9_0_4@18845 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 60 insertions, 0 deletions

diff --git a/trunk/missing/dup2.c b/trunk/missing/dup2.c
new file mode 100644
index 0000000000..7554084c5d
--- /dev/null
+++ b/trunk/missing/dup2.c
@@ -0,0 +1,60 @@
+/*
+ * Public domain dup2() lookalike
+ * by Curtis Jackson @ AT&T Technologies, Burlington, NC
+ * electronic address:  burl!rcj
+ *
+ * dup2 performs the following functions:
+ *
+ * Check to make sure that fd1 is a valid open file descriptor.
+ * Check to see if fd2 is already open; if so, close it.
+ * Duplicate fd1 onto fd2; checking to make sure fd2 is a valid fd.
+ * Return fd2 if all went well; return BADEXIT otherwise.
+ */
+
+#include "ruby/config.h"
+
+#if defined(HAVE_FCNTL)
+# include <fcntl.h>
+#endif
+
+#if !defined(HAVE_FCNTL) || !defined(F_DUPFD)
+# include <errno.h>
+#endif
+
+#define BADEXIT -1
+
+int
+dup2(int fd1, int fd2)
+{
+#if defined(HAVE_FCNTL) && defined(F_DUPFD)
+	if (fd1 != fd2) {
+#ifdef F_GETFL
+		if (fcntl(fd1, F_GETFL) < 0)
+			return BADEXIT;
+		if (fcntl(fd2, F_GETFL) >= 0)
+			close(fd2);
+#else
+		close(fd2);
+#endif
+		if (fcntl(fd1, F_DUPFD, fd2) < 0)
+			return BADEXIT;
+	}
+	return fd2;
+#else
+	extern int errno;
+	int i, fd, fds[256];
+
+	if (fd1 == fd2) return 0;
+	close(fd2);
+	for (i=0; i<256; i++) {
+		fd = fds[i] = dup(fd1);
+		if (fd == fd2) break;
+	}
+	while (i) {
+	    	close(fds[i--]);
+	}
+	if (fd == fd2) return 0;
+	errno = EMFILE;
+	return BADEXIT;
+#endif
+}