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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.

       -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 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  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 catalogue:/etc/X11/fontpath.d,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 1.15.0		    XSERVER(1)