XSERVER(1)                  General Commands Manual                 XSERVER(1)



NAME
       Xserver - X Window System display server

SYNOPSIS
       X [option ...]

DESCRIPTION
       X  is  the  generic name for the X Window System display server.  It is
       frequently a link or a copy of the appropriate server binary for  driv-
       ing the most frequently used server on a given machine.

STARTING THE SERVER
       The  X  server  is  usually  started from the X Display Manager program
       xdm(1) or a similar display manager program.  This utility is run  from
       the  system  boot  files  and takes care of keeping the server running,
       prompting for usernames and passwords, and starting up  the  user  ses-
       sions.

       Installations  that run more than one window system may need to use the
       xinit(1) utility instead of a display manager.  However, xinit is to be
       considered  a tool for building startup scripts and is not intended for
       use by end users.  Site administrators are strongly urged to use a dis-
       play manager, or build other interfaces for novice users.

       The  X  server  may  also  be started directly by the user, though this
       method is usually reserved for testing and is not recommended for  nor-
       mal  operation.   On some platforms, the user must have special permis-
       sion to start the X server, often because  access  to  certain  devices
       (e.g. /dev/mouse) is restricted.

       When  the  X server starts up, it typically takes over the display.  If
       you are running on a workstation whose console is the display, you  may
       not be able to log into the console while the server is running.

OPTIONS
       Many X servers have device-specific command line options.  See the man-
       ual pages for the individual  servers  for  more  details;  a  list  of
       server-specific manual pages is provided in the SEE ALSO section below.

       All  of  the X servers accept the command line options described below.
       Some X servers may have alternative ways of  providing  the  parameters
       described  here,  but  the values provided via the command line options
       should override values specified via other mechanisms.

       :displaynumber
               The X server runs as the given displaynumber, which by  default
               is  0.   If  multiple  X servers are to run simultaneously on a
               host, each must have a unique display number.  See the  DISPLAY
               NAMES  section  of the X(7) manual page to learn how to specify
               which display number clients should try to use.

       -a number
               sets pointer acceleration  (i.e.  the  ratio  of  how  much  is
               reported to how much the user actually moved the pointer).

       -ac     disables  host-based access control mechanisms.  Enables access
               by any host, and permits any host to modify the access  control
               list.   Use with extreme caution.  This option exists primarily
               for running test suites remotely.

       -audit level
               sets the audit trail level.  The default level  is  1,  meaning
               only  connection rejections are reported.  Level 2 additionally
               reports all successful connections and  disconnects.   Level  4
               enables  messages  from  the  SECURITY  extension,  if present,
               including generation and revocation of authorizations and  vio-
               lations  of  the  security policy.  Level 0 turns off the audit
               trail.  Audit lines are sent as standard error output.

       -auth authorization-file
               specifies a file which contains a collection  of  authorization
               records  used  to authenticate access.  See also the xdm(1) and
               Xsecurity(7) manual pages.

       -background none
               Asks the driver not to clear the background on startup, if  the
               driver supports that.  May be useful for smooth transition with
               eg. fbdev driver.  For security reasons this is not the default
               as the screen contents might show a previous user session.

       -br     sets  the  default  root  window  to solid black instead of the
               standard root weave  pattern.    This  is  the  default  unless
               -retro or -wr is specified.

       -bs     disables backing store support on all screens.

       -c      turns off key-click.

       c volume
               sets key-click volume (allowable range: 0-100).

       -cc class
               sets  the  visual  class  for the root window of color screens.
               The class numbers are as specified  in  the  X  protocol.   Not
               obeyed by all servers.

       -core   causes the server to generate a core dump on fatal errors.

       -displayfd fd
               specifies  a  file descriptor in the launching process.  Rather
               than specify a display number, the X  server  will  attempt  to
               listen on successively higher display numbers, and upon finding
               a free one, will write the display number  back  on  this  file
               descriptor  as  a newline-terminated string.  The -pn option is
               ignored when using -displayfd.

       -deferglyphs whichfonts
               specifies the types  of  fonts  for  which  the  server  should
               attempt  to  use deferred glyph loading.  whichfonts can be all
               (all fonts), none (no fonts), or 16 (16 bit fonts only).

       -dpi resolution
               sets the resolution for all screens, in dots per inch.   To  be
               used  when  the server cannot determine the screen size(s) from
               the hardware.

       dpms    enables DPMS (display power management  services),  where  sup-
               ported.   The  default state is platform and configuration spe-
               cific.

       -dpms   disables DPMS (display power management services).  The default
               state is platform and configuration specific.

       -extensionextensionName
               disables  named  extension.    If  an unknown extension name is
               specified, a list of accepted extension names is printed.

       +extensionextensionName
               enables named extension.   If  an  unknown  extension  name  is
               specified, a list of accepted extension names is printed.

       -f volume
               sets beep (bell) volume (allowable range: 0-100).

       -fc cursorFont
               sets default cursor font.

       -fn font
               sets the default font.

       -fp fontPath
               sets the search path for fonts.  This path is a comma separated
               list of directories which the X server searches for font  data-
               bases.   See  the  FONTS  section  of this manual page for more
               information and the default list.

       -help   prints a usage message.

       -I      causes all remaining command line arguments to be ignored.

       -iglx   Prohibit creating indirect GLX contexts.  Indirect  GLX  is  of
               limited use, since it lacks support for many modern OpenGL fea-
               tures and extensions; it's slower than direct contexts; and  it
               opens a large attack surface for protocol parsing errors.  This
               is the default unless +iglx is specified.

       +iglx   Allow creating indirect GLX contexts.

       -maxbigreqsize size
               sets the maximum big request to size MB.

       -nocursor
               disable the display of the pointer cursor.

       -nolisten trans-type
               disables a transport type.  For example, TCP/IP connections can
               be disabled with -nolisten tcp.  This option may be issued mul-
               tiple times to disable listening to different transport types.

       -noreset
               prevents a server reset when  the  last  client  connection  is
               closed.   This  overrides  a  previous  -terminate command line
               option.

       -p minutes
               sets screen-saver pattern cycle time in minutes.

       -pn     permits the server to continue running if it fails to establish
               all  of its well-known sockets (connection points for clients),
               but establishes at least one.  This option is set by default.

       -nopn   causes the server to exit if it fails to establish all  of  its
               well-known sockets (connection points for clients).

       -r      turns off auto-repeat.

       r       turns on auto-repeat.

       -retro  starts the stipple with the classic stipple and cursor visible.
               The default is to start with a black root window, and  to  sup-
               press display of the cursor until the first time an application
               calls XDefineCursor(). For kdrive servers, this implies -zap.

       -s minutes
               sets screen-saver timeout time in minutes.

       -su     disables save under support on all screens.

       -seat seat
               seat to run on. Takes a string identifying a seat in a platform
               specific  syntax.  On platforms which support this feature this
               may be used to limit the server to expose only a specific  sub-
               set of devices connected to the system.

       -t number
               sets  pointer  acceleration threshold in pixels (i.e. after how
               many pixels pointer acceleration should take effect).

       -terminate
               causes the server to terminate at server reset, instead of con-
               tinuing  to  run.   This  overrides a previous -noreset command
               line option.

       -to seconds
               sets default connection timeout in seconds.

       -tst    disables all testing extensions (e.g., XTEST,  XTrap,  XTestEx-
               tension1, RECORD).

       ttyxx   ignored, for servers started the ancient way (from init).

       v       sets video-off screen-saver preference.

       -v      sets video-on screen-saver preference.

       -wm     forces  the  default  backing-store  of all windows to be When-
               Mapped.  This is a backdoor way  of  getting  backing-store  to
               apply  to  all  windows.  Although all mapped windows will have
               backing store, the backing store attribute  value  reported  by
               the server for a window will be the last value established by a
               client.  If it has never been set by a client, the server  will
               report the default value, NotUseful.  This behavior is required
               by the X protocol,  which  allows  the  server  to  exceed  the
               client's  backing store expectations but does not provide a way
               to tell the client that it is doing so.

       -wr     sets the default root window to  solid  white  instead  of  the
               standard root weave pattern.

       -x extension
               loads  the  specified  extension  at init.  This is a no-op for
               most implementations.

       [+-]xinerama
               enables(+) or disables(-) the XINERAMA extension.  The  default
               state is platform and configuration specific.

SERVER DEPENDENT OPTIONS
       Some X servers accept the following options:

       -ld kilobytes
               sets the data space limit of the server to the specified number
               of kilobytes.  A value of zero makes the data size as large  as
               possible.   The default value of -1 leaves the data space limit
               unchanged.

       -lf files
               sets the number-of-open-files limit of the server to the speci-
               fied  number.  A value of zero makes the limit as large as pos-
               sible.  The default value of -1 leaves the limit unchanged.

       -ls kilobytes
               sets the stack space limit of the server to the specified  num-
               ber  of  kilobytes.   A  value  of zero makes the stack size as
               large as possible.  The default value of -1  leaves  the  stack
               space limit unchanged.

       -render default|mono|gray|color  sets  the color allocation policy that
               will be used by the render extension.

               default selects the default  policy  defined  for  the  display
                       depth of the X server.

               mono    don't use any color cell.

               gray    use  a  gray  map  of  13  color cells for the X render
                       extension.

               color   use a color cube of at most 4*4*4 colors  (that  is  64
                       color cells).

       -dumbSched
               disables  smart  scheduling on platforms that support the smart
               scheduler.

       -schedInterval interval
               sets the smart scheduler's scheduling interval to interval mil-
               liseconds.

XDMCP OPTIONS
       X  servers  that  support  XDMCP have the following options.  See the X
       Display Manager Control Protocol specification for more information.

       -query hostname
               enables XDMCP and sends Query packets to  the  specified  host-
               name.

       -broadcast
               enable  XDMCP and broadcasts BroadcastQuery packets to the net-
               work.  The first responding display manager will be chosen  for
               the session.

       -multicast [address [hop count]]
               Enable  XDMCP and multicast BroadcastQuery packets to the  net-
               work.  The first responding display manager is chosen  for  the
               session.   If an address is specified, the multicast is sent to
               that address.  If no address is  specified,  the  multicast  is
               sent to the default XDMCP IPv6 multicast group.  If a hop count
               is specified, it is used as the maximum hop count for the  mul-
               ticast.   If no hop count is specified, the multicast is set to
               a maximum of 1 hop, to prevent the multicast from being  routed
               beyond the local network.

       -indirect hostname
               enables  XDMCP  and send IndirectQuery packets to the specified
               hostname.

       -port port-number
               uses the specified port-number for XDMCP  packets,  instead  of
               the  default.  This option must be specified before any -query,
               -broadcast, -multicast, or -indirect options.

       -from local-address
               specifies the local address to connect from (useful if the con-
               necting  host  has  multiple  network  interfaces).  The local-
               address may be expressed in any form  acceptable  to  the  host
               platform's gethostbyname(3) implementation.

       -once   causes  the  server  to  terminate (rather than reset) when the
               XDMCP session ends.

       -class display-class
               XDMCP has an additional  display  qualifier  used  in  resource
               lookup  for  display-specific  options.   This option sets that
               value, by default it is "MIT-Unspecified" (not  a  very  useful
               value).

       -cookie xdm-auth-bits
               When  testing  XDM-AUTHENTICATION-1,  a  private  key is shared
               between the server and the manager.  This option sets the value
               of that private data (not that it is very private, being on the
               command line!).

       -displayID display-id
               Yet another XDMCP specific value, this one allows  the  display
               manager  to  identify  each  display  so that it can locate the
               shared key.

XKEYBOARD OPTIONS
       X servers that support the XKEYBOARD (a.k.a.  "XKB")  extension  accept
       the  following options.  All layout files specified on the command line
       must be located in the XKB base directory or a subdirectory, and speci-
       fied as the relative path from the XKB base directory.  The default XKB
       base directory is /usr/lib/X11/xkb.

       [+-]accessx [ timeout [ timeout_mask [ feedback [ options_mask ] ] ] ]
               enables(+) or disables(-) AccessX key sequences.

       -xkbdir directory
               base directory for keyboard layout files.  This option  is  not
               available  for setuid X servers (i.e., when the X server's real
               and effective uids are different).

       -ardelay milliseconds
               sets the autorepeat delay (length of time in milliseconds  that
               a key must be depressed before autorepeat starts).

       -arinterval milliseconds
               sets  the  autorepeat  interval (length of time in milliseconds
               that should elapse between autorepeat-generated keystrokes).

       -xkbmap filename
               loads keyboard description in filename on server startup.

NETWORK CONNECTIONS
       The X server supports client connections via a platform-dependent  sub-
       set  of the following transport types: TCPIP, Unix Domain sockets, DEC-
       net, and several varieties of SVR4 local connections.  See the  DISPLAY
       NAMES  section  of  the  X(7) manual page to learn how to specify which
       transport type clients should try to use.

GRANTING ACCESS
       The X server implements a platform-dependent subset  of  the  following
       authorization  protocols: MIT-MAGIC-COOKIE-1, XDM-AUTHORIZATION-1, XDM-
       AUTHORIZATION-2, SUN-DES-1, and MIT-KERBEROS-5.  See  the  Xsecurity(7)
       manual page for information on the operation of these protocols.

       Authorization  data  required  by  the above protocols is passed to the
       server in a private file named with  the  -auth  command  line  option.
       Each  time  the  server is about to accept the first connection after a
       reset (or when the server is starting), it reads this  file.   If  this
       file contains any authorization records, the local host is not automat-
       ically allowed access to the server, and only clients which send one of
       the authorization records contained in the file in the connection setup
       information will be allowed access.  See the  Xau  manual  page  for  a
       description  of the binary format of this file.  See xauth(1) for main-
       tenance of this file, and distribution of its contents to remote hosts.

       The X server also uses a host-based access control  list  for  deciding
       whether  or  not  to  accept  connections  from clients on a particular
       machine.  If no other authorization mechanism is being used, this  list
       initially  consists  of the host on which the server is running as well
       as any machines listed in the file /etc/Xn.hosts, where n is  the  dis-
       play number of the server.  Each line of the file should contain either
       an Internet hostname (e.g. expo.lcs.mit.edu) or a  DECnet  hostname  in
       double  colon  format  (e.g.  hydra::) or a complete name in the format
       family:name as described in the xhost(1) manual page.  There should  be
       no leading or trailing spaces on any lines.  For example:

               joesworkstation
               corporate.company.com
               star::
               inet:bigcpu
               local:

       Users  can  add  or  remove  hosts from this list and enable or disable
       access control using the xhost command from the  same  machine  as  the
       server.

       If  the  X  FireWall  Proxy  (xfwp) is being used without a sitepolicy,
       host-based authorization must be turned on for clients to  be  able  to
       connect to the X server via the xfwp.  If xfwp is run without a config-
       uration file and thus no sitepolicy is defined, if xfwp is using  an  X
       server  where xhost + has been run to turn off host-based authorization
       checks, when a client tries to connect to this X server via xfwp, the X
       server  will  deny  the  connection.   See xfwp(1) for more information
       about this proxy.

       The X protocol intrinsically does not have any notion of window  opera-
       tion  permissions or place any restrictions on what a client can do; if
       a program can connect to a display, it has full run of the  screen.   X
       servers that support the SECURITY extension fare better because clients
       can be designated untrusted via the authorization they use to  connect;
       see  the xauth(1) manual page for details.  Restrictions are imposed on
       untrusted clients that curtail the mischief they can do.  See the SECU-
       RITY extension specification for a complete list of these restrictions.

       Sites  that  have better authentication and authorization systems might
       wish to make use of the hooks in the libraries and the server  to  pro-
       vide additional security models.

SIGNALS
       The X server attaches special meaning to the following signals:

       SIGHUP  This  signal  causes  the  server to close all existing connec-
               tions, free all resources, and restore  all  defaults.   It  is
               sent  by  the  display  manager  whenever  the main user's main
               application (usually an xterm or window manager) exits to force
               the server to clean up and prepare for the next user.

       SIGTERM This signal causes the server to exit cleanly.

       SIGUSR1 This signal is used quite differently from either of the above.
               When the server starts, it checks to see if  it  has  inherited
               SIGUSR1 as SIG_IGN instead of the usual SIG_DFL.  In this case,
               the server sends a SIGUSR1 to its parent process after  it  has
               set  up  the various connection schemes.  Xdm uses this feature
               to recognize when connecting to the server is possible.

FONTS
       The X server  can  obtain  fonts  from  directories  and/or  from  font
       servers.   The  list  of directories and font servers the X server uses
       when trying to open a font is controlled by the font path.

       The            default             font             path             is
       /usr/share/fonts/X11/misc,/usr/share/fonts/X11/cyril-
       lic,/usr/share/fonts/X11/100dpi/:unscaled,/usr/share/fonts/X11/75dpi/:unscaled,/usr/share/fonts/X11/Type1,/usr/share/fonts/X11/100dpi,/usr/share/fonts/X11/75dpi,built-
       ins .

       A  special kind of directory can be specified using the catalogue: pre-
       fix. Directories specified this way can contain  symlinks  pointing  to
       the real font directories. See the FONTPATH.D section for details.

       The  font  path  can be set with the -fp option or by xset(1) after the
       server has started.

FONTPATH.D
       You can specify  a  special  kind  of  font  path  in  the  form  cata-
       logue:<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  'unscaled',  second  FPE will be /usr/share/X11/fonts/75dpi,
       also with 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


FILES
       /etc/Xn.hosts                 Initial  access  control list for display
                                     number n

       /usr/share/fonts/X11/misc,/usr/share/fonts/X11/75dpi,/usr/share/fonts/X11/100dpi
                                     Bitmap font directories

       /usr/share/fonts/X11/TTF,/usr/share/fonts/X11/Type1
                                     Outline font directories

       /tmp/.X11-unix/Xn             Unix domain socket for display number n

       /usr/adm/Xnmsgs               Error  log  file  for display number n if
                                     run from init(8)

       /usr/lib/X11/xdm/xdm-errors   Default error log file if the  server  is
                                     run from xdm(1)

SEE ALSO
       General information: X(7)

       Protocols:  X  Window  System  Protocol, The X Font Service Protocol, X
       Display Manager Control Protocol

       Fonts: bdftopcf(1), mkfontdir(1), mkfontscale(1), xfs(1),  xlsfonts(1),
       xfontsel(1), xfd(1), X Logical Font Description Conventions

       Keyboards: xkeyboard-config(7)

       Security:  Xsecurity(7),  xauth(1),  Xau(1), xdm(1), xhost(1), xfwp(1),
       Security Extension Specification

       Starting the server: startx(1), xdm(1), xinit(1)

       Controlling the server once started:  xset(1),  xsetroot(1),  xhost(1),
       xinput(1), xrandr(1)

       Server-specific  man  pages:  Xorg(1),  Xdmx(1),  Xephyr(1),  Xnest(1),
       Xvfb(1), Xquartz(1), XWin(1).

       Server internal documentation: Definition of the Porting Layer for  the
       X v11 Sample Server

AUTHORS
       The  sample server was originally written by Susan Angebranndt, Raymond
       Drewry, Philip Karlton, and Todd Newman, from Digital Equipment  Corpo-
       ration,  with support from a large cast.  It has since been extensively
       rewritten by Keith Packard and Bob Scheifler, from MIT.   Dave  Wiggins
       took over post-R5 and made substantial improvements.



X Version 11                  xorg-server 1.16.4                    XSERVER(1)
