X font server


       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).


       -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.

              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.

       -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.

              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

       -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.


       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.

       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

       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

       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).


       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