diff -uNrBbd openssh-5.1p1.org/ssh.c openssh-5.1p1.new/ssh.c
--- openssh-5.1p1.org/ssh.c	2008-07-04 04:53:50.000000000 +0200
+++ openssh-5.1p1.new/ssh.c	2009-02-18 21:15:26.000000000 +0100
@@ -140,6 +140,9 @@
 /* optional user configfile */
 char *config = NULL;
 
+/* file to write the pid in after daemonizing */
+char *pid_file = NULL;
+
 /*
  * Name of the host we are connecting to.  This is the name given on the
  * command line, or the HostName specified for the user-supplied name in a
@@ -185,6 +188,7 @@
 "           [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
 "           [-R [bind_address:]port:host:hostport] [-S ctl_path]\n"
 "           [-w local_tun[:remote_tun]] [user@]hostname [command]\n"
+"           [-z pid_file]\n"
 	);
 	exit(255);
 }
@@ -197,6 +201,26 @@
 void muxclient(const char *);
 void muxserver_listen(void);
 
+int write_pid_file(char *pid_file)
+{
+	char buffer[16];
+	int len;
+	int fd = open(pid_file, O_WRONLY | O_EXCL | O_CREAT, 0644);
+	if (fd == -1)
+		return -1;
+
+	len = snprintf(buffer, sizeof(buffer), "%d\n", getpid());
+	if (write(fd, buffer, len) != len)
+	{
+		close(fd);
+		return -1;
+	}
+
+	close(fd);
+
+	return 0;
+}
+
 /*
  * Main program for the ssh client.
  */
@@ -271,9 +295,12 @@
 	host = NULL;
 
  again:
-	while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
+	while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvxz:"
 	    "ACD:F:I:KL:MNO:PR:S:TVw:XY")) != -1) {
 		switch (opt) {
+		case 'z':
+			pid_file = optarg;
+			break;
 		case '1':
 			options.protocol = SSH_PROTO_1;
 			break;
@@ -833,6 +860,9 @@
 	if (options.control_path != NULL && muxserver_sock != -1)
 		unlink(options.control_path);
 
+	if (pid_file)
+		unlink(pid_file);
+
 	/*
 	 * Send SIGHUP to proxy command if used. We don't wait() in
 	 * case it hangs and instead rely on init to reap the child
@@ -1080,6 +1110,12 @@
 			fatal("daemon() failed: %.200s", strerror(errno));
 	}
 
+	if (pid_file)
+	{
+		if (write_pid_file(pid_file) == -1)
+			fatal("write_pid(%s) failed: %.200s", pid_file, strerror(errno));
+	}
+
 	/*
 	 * If a command was specified on the command line, execute the
 	 * command now. Otherwise request the server to start a shell.
@@ -1223,6 +1259,12 @@
 			fatal("daemon() failed: %.200s", strerror(errno));
 	}
 
+	if (pid_file)
+	{
+		if (write_pid_file(pid_file) == -1)
+			fatal("write_pid(%s) failed: %.200s", pid_file, strerror(errno));
+	}
+
 	return client_loop(tty_flag, tty_flag ?
 	    options.escape_char : SSH_ESCAPECHAR_NONE, id);
 }