Provided by: xfs_1.0.8-2.1_i386
xfs - X font server
xfs [ -config configuration_file ] [ -daemon ] [ -droppriv ] [ -ls
listen_socket ] [ -nodaemon ] [ -port tcp_port ] [ -user username ]
xfs is the X Window System font server. It supplies fonts to X Window
System display servers. The server is usually run by a system
administrator, and started via init(8). Users may also wish to start
private font servers for specific sets of fonts.
To connect to a font server, see the documentation for your X server;
it likely supports the syntax documented in the “FONT SERVER NAMES”
section of X(7).
specifies the configuration file xfs will use. If this
parameter is not specified, xfs will read its configuration from
the default file, /etc/X11/fs/config.
instructs xfs to fork and go into the background automatically
at startup. If this option is not specified, xfs will run as a
regular process (unless it was built to daemonize by default).
When running as a daemon, xfs will attempt to create a file in
which it stores its process ID, and will delete that file upon
instructs xfs to attempt to run as user and group xfs (unless
the -user option is used). This has been implemented for
security reasons, as xfs may have undiscovered buffer overflows
or other paths for possible exploit, both local and remote.
When using this option, you may also wish to specify ‘no-listen
= tcp’ in the config file, which ensures that xfs will not to
use a TCP port at all. By default, xfs runs with the user and
group IDs of the user who invoked it.
specifies a file descriptor which is already set up to be used
as the listen socket. This option is only intended to be used
by the font server itself when automatically spawning another
copy of itself to handle additional connections.
instructs xfs not to daemonize (fork and detach from its
controlling terminal). This option only has an effect if xfs is
built to daemonize by default, which is not the stock
specifies the TCP port number on which the server will listen
for connections. The default port number is 7100. This option
is ignored if xfs is configured to not listen to TCP transports
at all (see “Configuration File Format” below).
instructs xfs to run as the user username. See -droppriv for
why this may be desired. By default, xfs runs with the user and
group IDs of the user who invoked it.
xfs reads and serves any font file format recognized by the X server
itself. It locates font files through the specification of a
catalogue, which is declared in xfs’s configuration file.
Configuration File Format
xfs reads its configuration from a text file (see the -config option in
the “OPTIONS” section above). The configuration language is a list of
keyword and value pairs. Each keyword is followed by an equals sign
(‘=’) and then the desired value.
Recognized keywords include:
alternate-servers (list of strings)
lists alternate servers for this font server. See the “FONT
SERVER NAMES” section of X(7) for the syntax of the string.
catalogue (list of strings)
declares as ordered list of font path element names from which
fonts will be served. The current implementation only supports
a single catalogue ("all") containing all of the specified
fonts. A special directory with symlinks to font paths can be
specified using a catalogue:<dir> entry. See the CATALOGUE DIR
section below for details.
determines the number of clients this font server will support
before refusing service. This is useful for tuning the load on
each individual font server.
indicates whether this font server should attempt to clone
itself when the number of connected clients reaches the
The default pointsize (in decipoints) for font requests that
don’t specify a point size. The default is 120.
default-resolutions (list of resolutions)
indicates the resolutions the server supports by default. This
information may be used as a hint for pre-rendering, and
substituted into requests for scaled fonts which do not specify
a resolution. A resolution is a comma-separated pair of
horizontal and vertical resolutions in pixels per inch.
Multiple resolutions are separated by commas.
sets the mode for delayed fetching and caching of glyphs.
string should be one of ‘none’, meaning glyphs deferment is
disabled, ‘all’, meaning it is enabled for all fonts, and ‘16’,
meaning it is enabled only for 16-bit fonts.
indicates the filename of the error file. All warnings and
errors will be logged here, unless use-syslog is set to a true
value (see below).
disables the specified transport type. For example, TCP/IP
connections can be disabled with ‘no-listen = tcp’.
indicates the TCP port on which the server will listen for
determines whether errors and diagnostics should be reported via
syslog(3) (on supported systems) instead of being written to the
error-file (see above).
You can specify a special kind of font path in the form
catalogue:<dir>. The directory specified after the catalogue: prefix
will be scanned for symlinks and each symlink destination will be added
as a local fontfile FPE.
The symlink can be suffixed by attributes such as ’unscaled’, which
will be passed through to the underlying fontfile FPE. The only
exception is the newly introduced ’pri’ attribute, which will be used
for ordering the font paths specified by the symlinks.
An example configuration:
75dpi:unscaled:pri=20 -> /usr/share/X11/fonts/75dpi
ghostscript:pri=60 -> /usr/share/fonts/default/ghostscript
misc:unscaled:pri=10 -> /usr/share/X11/fonts/misc
type1:pri=40 -> /usr/share/X11/fonts/Type1
type1:pri=50 -> /usr/share/fonts/default/Type1
This will add /usr/share/X11/fonts/misc as the first FPE with the
attribute the attribute unscaled etc. This is functionally equivalent
to setting the following font path:
Example Configuration File
# sample font server configuration file
# allow a max of 10 clients to connect to this font server.
client-limit = 10
# When a font server reaches the above limit, start up a new one.
clone-self = on
# Identify alternate font servers for clients to use.
alternate-servers = hansen:7101,hansen:7102
# Look for fonts in the following directories. The first is a set of
# TrueType outlines, the second is a set of misc bitmaps (such as terminal
# and cursor fonts), and the last is a set of 100dpi bitmaps.
catalogue = /usr/X11R6/lib/X11/fonts/TTF,
# in 12 points, decipoints
default-point-size = 120
# 100 x 100 and 75 x 75
default-resolutions = 100,100,75,75
# Specify our log filename.
error-file = /var/log/xfs.log
# Direct diagnostics to our own log file instead of using syslog.
use-syslog = off
When operating in daemon mode, xfs sends diagnostic messages (errors
and warnings) to the system log via the syslog C library function by
default. However, these messages can be sent to an alternate location
via the error-file and use-syslog configuration variables; see
“Configuration File Format”, above.
xfs handles the following signals specially:
causes the font server to exit cleanly.
causes xfs to re-read its configuration file.
causes xfs to flush any cached data it may have.
SIGHUP causes xfs to reset, closing all active connections and re-
reading the configuration file.
Multiple catalogues should be supported.
Significant further development of xfs is unlikely. One of the
original motivations behind it was the single-threaded nature of the X
server — a user’s X session could seem to ‘freeze up’ while the X
server took a moment to rasterize a font. This problem with the X
server, which remains single-threaded in all popular implementations to
this day, has been mitigated on two fronts: machines have gotten much
faster, and client-side font rendering (particularly via the Xft
library) is the norm in contemporary software.
Dave Lemke, Network Computing Devices, Inc
Keith Packard, Massachusetts Institute of Technology
X(7), xfsinfo(1), fslsfonts(1), init(8), syslog(3), The X Font Service
Protocol, Font Server Implementation Overview