We will presume for the following examples that we have picked a fairly stable window manager, such as FVWM2, to try out some sample configurations. I would suggest giving that a shot for the purpose of learning these topics, as most of what you will learn here and in the following sections will apply to any window manager out there, but the topics seem most easily picked up using FVWM2.
Our first step is to write ourselves an initialization file for X
itself. This file can be either a system-wide file, in which case it
would likely be placed in /var/X11R6/lib/xinit/xinitrc, or
it can be overridden on a per-user basis by placing the file
.xinitrc in your home directory. Generally, it is expected
that there will be a basic, default file in the system-wide location,
possibly enforced if necessary for security reasons, but otherwise
users will probably wish to configure the file themselves.
First let's create a file in your home directory called
.xinitrc. Open up your ``favorite'' text editor, and paste
the following, or something like it, in that file:
#!/bin/sh
# if your backspace and delete are reversed, try this:
xmodmap -e "keysym BackSpace=Delete" -e "keysym
Delete-BackSpace"
xsetroot -solid darkslateblue
# start some basic applications
xclock -geometry 96x96+2+2 -bg grey40 -fg black -hl white &
xload -geometry 120x96+2+147 -bg grey40 -fg white -hl darkred -update 4
&
xterm -sb -ls -geom 80x25-2+2 -title "shell" &
xterm -sb -ls -geom 80x25-2-2 &
# start the window manager
fvwm2
There are plenty of things to learn from this example. First of all, this file will be a shell script, as indicated by the first line. The xsetroot command on the second line turns the background of our desktop to a pleasant blue color, not a bad idea if we're going to be staring at that color predominantly all day.
The third and fourth lines are some programs that I like to leave running while I'm fast at work. You'll notice that some of the options make for a nicer setup, for example, specifying the colors and geometry (location on screen). I'll give you some tips for figuring this stuff out in a bit. The fifth and sixth lines follow similarly, opening up two handy xterm windows for us, which we will no doubt be needing soon.
The last line is very important--it is this line that starts up your window manager! Notice that the only commands we did not run as background processes (by putting the & at the end) were xsetroot, xmodmap, fvwm2. With these first two it doesn't matter, as the programs exit immediately. But all the rest of the programs have to be in the background, otherwise when you closed one, it would kill your X Window session. That would not be very pleasant, nor very expected. As shown above, when you close fvwm2, you exit X.
We can add lots to our primitive example of a startup file. For instance, this is a good way to warn yourself when you may have carelessly stared X as the root user. Red Hat users seem to do this often, for many of the configuration programs which must be run as root, must also be run in X. You can avoid this by issuing an su command to become root during your normal X user session, and then calling the program you need to run as root with the option -display :0.0 discussed above.
# change background color for root
if [ "$USER" = "root" ];
then
xsetroot -solid darkred
else xsetroot -solid darkslateblue
fi
This will check to see if you are the user named root, and if you are,
it will set the background to a harsh red, rather than the usual
friendly blue, to warn you. This next bit of code, also intended for
your
.xinitrc file, will merge in your user-specific and
system-wide
resources, first checking to be sure the files exist.
userresources=$HOME/.Xresources
usermodmap=$HOME/.Xmodmap
sysresources=/usr/X11R6/lib/X11/xinit/.Xresources
sysmodmap=/usr/X11R6/lib/X11/xinit/.Xmodmap
# Merge in defaults and keymaps
if [ -f $sysresources ]; then
xrdb -merge $sysresources; fi
if [ -f $sysmodmap ]; then
xmodmap $sysmodmap; fi
if [ -f $userresources ]; then
xrdb -merge $userresources; fi
if [ -f $usermodmap ]; then
xmodmap $usermodmap; fi
Placing everything on your screen by guesswork with the -geometry option can get very tedious indeed. Particularly when you consider that you can specify the -geometry option to pretty much any program you can run in X. This allows a great precision in tuning the interface, but that's a heck of a lot of options to set, indeed.
This brings up one very nice feature of the FVWM window managers. By default, when you move a window around the screen, you see the geometry specification appear on the screen. Go ahead, try moving a window around with the left button. Now try resizing it. As you can see, you can get some primitive specifications this way. However, even this method can be a little difficult, and it would be nice to have all the details about your window in one concise list.
It is at this point that we will introduce the program xwininfo. To use this program, go to an xterm window and type in that program name. It will ask you to click on another window that you want information about, and after you click it will dump out useful information that it knows about that window. This is useful for plugging information about windows once you have them set up how you want them on your screen - run this program, then click on the window, then put in those parameters in your startup file, and your window system will henceforth be frozen in a pristine state of immaculate precision.