Choosing Screen Fonts and Colors

The first step in customizing your xterm is to select font sizes for text, and colors for the foreground and background, which will help you view the windows comfortably. (We suspect the default fonts and colors were selected by some plaid-panted programmer after spending all night writing code and drinking Coke.) Fortunately the setup is easy. You first examine the available choices; then you decide which names you prefer placing in the .Xdefaults file in your home directory so they become the defaults. A standard set of options for xterm is:   

% xterm -display host:n -geom wxh+x+y -fn font  -bg color -fg color -e command   	    

Now let's make these more suitable for you. If you do not have a color screen, go ahead and ignore the color option. (We actually find black and white displays easier to read.)

Figure 4.7 shows some standard X11 monospaced fonts and their aliases. Changing fonts in your xterm window is not as simple as in Macintosh applications where you just choose a font from a menu. (The X11 R4 and R5 xterms do have font menus, but you need to set up the menu before using it.) The present standard, X11 R3, has a total of 157 different fonts to experiment with (counting all of the different type faces and sizes) and the new X11 R4 has more than 400. While not all vendors supply every font, some provide additional fonts for a more distinctive look. The large number of fonts means that a naming convention was needed which completely specifies the characteristics of every font. The new X11 R3 naming convention is consistent with the X documentation's fondness for succinctness: 

   
adobe-courier-bold-r-normal-18-180-75-75-m-110-iso8859-1   	     

 
Figure: A sample of X11 monospaced fonts.
Click on figure to view larger image. 

$ xterm -fn adobe-courier-bold-r-normal-18-180-75-75-m-110-iso8859-1   	   

Is this a bit much? Fortunately, wild cards can be used to shorten the name and still unambiguously specify the font:

$ xterm -fn '*-courier-bold-r-*-18-*'   	 Short version.     

Notice the quotes ' ' are used so the shell does not try to fill in the *'s. You also can use -courier-bold-r-18- to prevent substitution for the *'s if the quotes become too difficult, as they may when you try putting commands into a mwm menu.

Font names become even more confusing when you encounter the local aliases by which any given font may be known. For example, the font above may also be called cour.b.18 and courb18. You clearly need some help before making your choice and, fortunately, the system comes through for you. The command xlsfonts lists all of the fonts available on your system in both the X11 R3 naming convention and any aliases. The list may be long, so you may want to pipe it to more or direct the output to a file:

$ xlsfonts | more   	Examine fonts through more.    
$ xlsfonts > fontfile   	Store fonts in file.    

As usual, the list tells you the names of the fonts but not what the fonts look like. To preview the fonts, you may use the xfontsel command, if it is available.

It is generally best to use xterm fonts in which each character is of the same width (like on a typewriter) because monospaced fonts preserve the alignment and spacing of the output from the system. Choose fonts that look good to you, and then test them with the command: 

$ xterm -fn font_name   	Examine fonts.     

The X Window System also gives you the option of selecting colors for the background, foreground, windows, and fonts. Colors are a little simpler than fonts. Many color terminals have 256 colors available, but the limited memory on less expensive satellite terminals, such as X terminals, limits the options to 16. There may be programs available on your system to preview the colors:

$ xcolors   	 Show available colors.    
$ xterm -fn font_name -bg  color -fg color