Fonts
Red Hat Linux uses xfs (X Font Server) to provide fonts to the XFree86 server and the X client applications that connect to it. While it is possible to not use xfs and place the paths to font directories in your XF86Config and XF86Config-4 configuration files, xfs has several advantages:
It is easier to add and remove fonts, including editing the font path. The font path is a collection of paths in the filesystem where font files are stored. The xfs service keeps the font path out of the XFree86 configuration files, making it easier to edit.
Fonts may be stored on one machine acting as a networked font server, and the fonts can be shared among muliple X servers over the network. A common set of fonts can be maintained in one place, and easily shared between all users.
More types of fonts are supported. xfs can handle TrueType, Type1, and bitmap fonts.
The XFree86 configuration files know whether to use xfs or hard coded font paths because of the FontPath setting in their Files sections. By default, the FontPath is set to unix/:7100. This tells the XFree86 server to connect to port 7100 using an inner-machine communication link. The xfs server listening on this port and will respond with font information when queried by the XFree86 server.
The xfs service must be running when X is started. If it is not, you will be returned to a command prompt with an error similar to failed to set default font path 'unix/:7100'. Check to see if xfs is running using the ps aux | grep xfs command. By default, xfs is set to start in runlevels 2, 3, 4, and 5, covering all runlevels where you would run X. If xfs is not running on your system, you can start it as root using the service xfs start command. Use the serviceconf or chkconfig utilities to force it to start at the correct runlevels.
xfs Configuration
The /etc/rc.d/init.d/xfs script starts the xfs server. Several options can be configured in the /etc/X11/fs/config file:
alternate-servers — Sets a list of alternate font servers to be used if this font server is not available. A comma must separate every font server in the list.
catalogue — An ordered list of font paths to use that contain the font files. A comma must follow every font path before a new font path can be started in the list.
You can use the string :unscaled immediately after the font path to make the unscaled fonts in that path load first. Then, you can specify the entire path again, so that other scaled fonts will also be loaded.
client-limit — Sets the number of clients this font server will service before refusing to handle any more. The default is 10.
clone-self — Decides if the font server will clone a new version of itself when the client-limit is hit. By default, this option is on. Set it to off to disable this feature.
default-point-size — Sets the default point size for any font that does not specify this value. The value for this option is set in decipoints. The default of 120 corresponds to 12 point fonts.
default-resolutions — Specifies a list of resolutions supported by the XFree86 server. Each resolution in the list must be separated by a comma.
deferglyphs — Tells xfs whether to defer the loading of glyphs, which is an image used to visually represent a font. You can disable this feature (none), enable this feature for all fonts (all), or turn this this feature on only for 16-bit fonts (16), which are largely used with Asian languages.
error-file — Allows you to specify the path and file name of a locations where xfs errors can be logged.
no-listen — Tells xfs not to listen using a particular protocol. By default, this option is set to tcp to prevent xfs from listening on TCP ports, primarily for security reasons. If you plan on using xfs to serve fonts to networked workstations on a LAN, you need to remove the tcp from this line.
port — Specifies the TCP port that xfs will listen on if no-listen does not exist or is commented out.
use-syslog — Tells xfs to use the system error log if set to on.
Adding Fonts
When using xfs, adding fonts to your system is rather straightforward. Use the chkfontpath --list command to see the font paths currently configured on your system. To add new fonts in a new directory, follow these instructions as the root user:
Create a font directory, such as /usr/share/fonts, and place the fonts inside that directory. Be sure to set the permissions correctly; it is only necessary that the files can be read, no other permissions are necessary.
Type the chkfontpath --add <font-directory-path> command, where the <font-directory-path> is the full path to the directory holding the fonts. This will add this font path to the xfs configuration file.
Note You must have a fonts.dir file in your new font directory for the chkfontpath command to work correctly. The creation of the fonts.dir file, as well as any other files used by xfs with these fonts, is beyond the scope of this document.
Many font collections available for Linux include these files for you, it may not be necessary to create them by hand.
Restart xfs using the service xfs restart command. You will also need to restart your X session.
Typing the chkfontpath --list command will show the new font path. Any fonts you added are now available for use.
The Red Hat Support website contains more information on this subject, see http://www.redhat.com/support for additional help documents.