Many vendors and local support groups have provided their own methods
for users to start up the X Window System. As you might expect after
our introductory grumbling, even on one machine the method may differ
if you are at the console or at an X terminal.
Frequently Unix itself starts up X
without any user encouragement. In that case, Unix both initiates X
and opens a special window on the display asking you to log in. Once
you have logged in, the login window may drop out of view and your
customized environment may be created on the screen (or the
default if you have been lazy).
Another common method for starting X is to log in in your normal way, and then issue the command xinit or xtstart. The programs run by these commands, as well other X programs, are usually kept in the directory /usr/bin/X11. You should add this directory to PATH in your .profile, as described in Chapter 2, Workstation Setup and Use, and in Appendix 6. If you are so inclined, you may browse through this directory to see some of the X commands available to you.
Once you have started X, you probably will see the screen turn gray, see one or more windows appear, as in Figure 4.1, and see the mouse pointer become activated (it's usually a small arrow). If you have trouble locating the mouse pointer on the screen, just roll the mouse around on its pad to get the pointer jumping around. While discussing mice, please note that from now on we will be lazy and suggest you move your ``mouse'' into some object on the screen when we really mean move your mouse's pointer. Keep your mouse on its pad; in fact, we recommend that you always keep your mouse on a clean mouse pad for precision of motion and protection of mouse.
As far as X is concerned, all mice have three buttons. While some mice may actually not have three buttons, operationally X assumes they do. For mice with only two buttons, depressing both simultaneously is equivalent to depressing the middle button:
If you can get your hands on your computer now, try moving the mouse around on the screen. Notice what happens when the mouse is pointed at various objects (parts of the screen) and different buttons are clicked or held down. Don't worry too much about "breaking" or confusing the system with your clicking; just try to get a feel for how the components making up X work. When you confuse or damage X beyond repair, just kill X and start again using the procedures described below.
Figure: X11 and Motif window environment.
Click on figure to view larger image.