Getting started with X11 on Mac

Now that you know what X11 is good for, it’s time to play with it. First, launch /Applications/Utilities/X11.app. If this doesn’t exist, install it from an OS X DVD.

If you give keyboard/mouse focus to any X11 window, you’ll get X11.app’s menu bar. X11 software puts menus inside client windows. It’s the price of portability.

Unlocking the Mac’s X11 applications and documentation

To get to OS X’s standard set of X11 applications and man pages, you need to edit either ~/.profile or ~/.cshrc to alter your PATH and MANPATH environment variables. I use bash, so I added these lines to the bottom of ~/.profile:

export PATH=/usr/X11R6/bin:$PATH

export MANPATH=/usr/X11R6/man:$MANPATH

export DISPLAY=localhost:0.0

Without DISPLAY set properly, X11 won’t function. if you run into trouble, this is the first thing to suspect. DISPLAY won’t match the value shown above if you’re attached to a remote system. I’ll explain that in my next post.

Launching applications automatically when X11 starts

There’s one more file you want to change or create: ~/.xinitrc. Here’s where you put the commands you want to run every time X11.app starts. At a minimum, this should read:

quartz-wm &

xterm

As a rule, launch interactive X11 applications in the background, as with quartz-wm above. That’s as true for the command line as it is for ~/.xinitrc. Let the last command in ~/.xinitrc run in the foreground. When that last application exits, X11.app will either quit or wait for you to launch a new client application. Other X11 servers may reset or log you out.

X11’s workhorse, xterm

Now you’re ready for your first X11 app, the one in which you’ll likely spend most of your time. Open up an OS X Terminal window and type:

xterm &

xterm isn’t much to look at, but it has tons of command-line options; see the man page. Learn to love xterm, because it’s the only terminal you can count on across all X11 implementations.

If you can’t pull up a context menu in an X11 app like xterm, it might be triggered by mouse button 3. You can map virtual mouse buttons in X11.app’s preferences. You can also set shortcuts for frequently-used clients in X11.app’s Application menu. And you can always launch a new xterm instance by typing “xterm &” in an xterm window. Remember, launch X11 clients in the background.

Everything you just learned about xterm applies to X11 clients in general. It’s not rocket science.

In the next and final part of this series, you’ll learn how easy it is to use X11 to connect to remote hosts. In the meantime, rummage around in /usr/X11R6/bin. Most of the commands there have man pages, and any local client can be launched from an xterm window.