Mac OS X Tiger in a Nutshell

Connecting to Other X Window Systems

You can connect from Mac OS X to other X Window systems using ssh with X11 forwarding. If you use OpenSSH (which is included with Mac OS X), you must use the -X option to request X11 forwarding. When used with the ssh command, the -2 option specifies the SSH Version 2 protocol, as opposed to the older Version 1 protocol. For example:

$ ssh -2 -X remotemachine -l
                
               
                  username
               

As long as X11 is running, this can be entered in either an xterm window or in the Terminal. To have the X11 forwarding enabled in Terminal, you must have the DISPLAY variable set prior to making the connection. Under the bash shell (and other Bourne-compatible shells) use:

DISPLAY=:0.0; export DISPLAY

Under csh and tcsh, use:

setenv DISPLAY :0.0

It is also possible to create a double-clickable application that connects to a remote machine via SSH 2, with X11 forwarding enabled. For example, you can use the following script for this purpose:

#!/bin/sh
DISPLAY=:0.0; export DISPLAY
/usr/X11R6/bin/xterm -e ssh -2 -X remotemachine -l username

If you’ve installed the commercial version of SSH from http://www.ssh.com, the equivalent of the preceding script is as follows:

#!/bin/sh
DISPLAY=:0.0; export DISPLAY
/usr/X11R6/bin/xterm -e ssh2 remotemachine -l username

Tip

The X11 forwarding flag is +x with the commercial SSH, but it is enabled by default, so you need not include it in the command.

Using Apple’s X11, you can add an Application menu item to accomplish the same task. To do this, start ...