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XSERVER(1)									       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 driving 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 sessions.

       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 display 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 normal operation.  On some platforms,  the
       user  must  have special permission 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 manual  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 violations 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 dis-
	       play 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	supported.   The  default
	       state is platform and configuration specific.

       -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  directo-
	       ries  which  the  X  server searches for font databases.  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.

       -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 multiple 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 suppress display of the cursor until the
	       first time an application calls XDefineCursor().  For the Xorg server,  this  also
	       sets  the  default  for	the  DontZap  option  to FALSE.  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 subset 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 continuing 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, XTestExtension1, 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 WhenMapped.  This is a back-
	       door  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 specified number.	A
	       value of zero makes the limit as large as  possible.   The  default  value  of  -1
	       leaves the limit unchanged.

       -ls kilobytes
	       sets  the stack space limit of the server to the specified number 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 milliseconds.

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

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

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

       -multicast [address [hop count]]
	       Enable XDMCP and multicast BroadcastQuery packets  to  the   network.   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 multicast.  If no hop count is  speci-
	       fied,  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  connecting	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-spe-
	       cific  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 specified as the relative path from the XKB base direc-
       tory.  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 subset of the following
       transport types: TCPIP, Unix Domain sockets, DECnet, and several varieties of  SVR4  local
       connections.   See the DISPLAY NAMES section of the X(7) manual page to learn how to spec-
       ify which transport type clients should try to use.

GRANTING ACCESS
       The X server implements a platform-dependent subset of the following authorization  proto-
       cols:  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  automatically
       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
       maintenance 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 mecha-
       nism is being used, this list initially consists of the host on which the server  is  run-
       ning as well as any machines listed in the file /etc/Xn.hosts, where n is the display num-
       ber 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  authoriza-
       tion must be turned on for clients to be able to connect to the X server via the xfwp.  If
       xfwp is run without a configuration 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  con-
       nection.  See xfwp(1) for more information about this proxy.

       The  X  protocol intrinsically does not have any notion of window operation 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 SECURITY 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 provide additional security models.

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

       SIGHUP  This signal causes  the	server	to  close  all	existing  connections,	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 rec-
	       ognize 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 catalogue:/etc/X11/fontpath.d,built-ins .

       A  special  kind  of  directory	can be specified using the catalogue: prefix. 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 catalogue:<dir>.  The directory
       specified after the catalogue: prefix will be scanned for symlinks and each symlink desti-
       nation 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 '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 Con-
       trol 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 Corporation, 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 1.15.0			       XSERVER(1)
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