xfs(1)                                                        General Commands Manual                                                       xfs(1)

NAME

       xfs - X font server

SYNOPSIS

       xfs [ -config configuration_file ] [ -daemon ] [ -droppriv ] [ -ls listen_socket ] [ -nodaemon ] [ -port tcp_port ] [ -user username ]

DESCRIPTION

       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).

OPTIONS

       -config configuration_file
              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.

       -daemon
              instructs xfs to fork and go into the background automatically at startup.  If this option is not specified, xfs will run as a regu-
              lar  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 exit;

       -droppriv
              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.

       -ls listen_socket
              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.

       -nodaemon
              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 configuration.

       -port tcp_port
              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).

       -user username
              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.

INPUT FILES

       xfs  reads  and  serves any font file format recognized by the X server itself.  It locates font files through the specification of a cata-
       logue, 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.

       client-limit (cardinal)
              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.

       clone-self (boolean)
              indicates whether this font server should attempt to clone itself when the number of connected clients reaches the client-limit.

       default-point-size (cardinal)
              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.

       deferglyphs (string)
              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.

       error-file (string)
              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).

       no-listen (trans-type)
              disables the specified transport type.  For example, TCP/IP connections can be disabled with 'no-listen = tcp'.

       port (cardinal)
              indicates the TCP port on which the server will listen for connections.

       use-syslog (boolean)
              determines whether errors and diagnostics should be reported via syslog(3) (on supported systems) instead of being  written  to  the
              error-file (see above).

CATALOGUE DIR

       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  excep-
       tion 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:

           /usr/share/X11/fonts/misc:unscaled,
           /usr/share/X11/fonts/75dpi:unscaled,
           /usr/share/X11/fonts/Type1,
           /usr/share/fonts/default/Type1,
           /usr/share/fonts/default/ghostscript

   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,
                   /usr/X11R6/lib/X11/fonts/misc,
                   /usr/X11R6/lib/X11/fonts/100dpi/

       # 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

OUTPUT FILES

       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 "Con-
       figuration File Format", above.

ASYNCHRONOUS EVENTS

       xfs handles the following signals specially:

       SIGTERM
              causes the font server to exit cleanly.

       SIGUSR1
              causes xfs to re-read its configuration file.

       SIGUSR2
              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.

BUGS

       Multiple catalogues should be supported.

FUTURE DIRECTIONS

       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.

AUTHORS

       Dave Lemke, Network Computing Devices, Inc
       Keith Packard, Massachusetts Institute of Technology

SEE ALSO

       X(7), xfsinfo(1), fslsfonts(1), init(8), syslog(3), The X Font Service Protocol, Font Server Implementation Overview

X Version 11                                                         xfs 1.0.8                                                              xfs(1)