XSERVER(1)                  General Commands Manual                 XSERVER(1)

       Xserver - X Window System display server

       X [option ...]

       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.

       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

       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.

       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.

               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 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
               supported.  The default state is platform and configuration

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

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

               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
               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.

       -iglx   Prohibit creating indirect GLX contexts.  Indirect GLX is of
               limited use, since it lacks support for many modern OpenGL
               features 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.

               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.  Supported transport types are platform dependent, but
               commonly include:

               tcp     TCP over IPv4 or IPv6
               inet    TCP over IPv4 only
               inet6   TCP over IPv6 only
               unix    UNIX Domain Sockets
               local   Platform preferred local connection method

       -listen trans-type
               enables a transport type.  For example, TCP/IP connections can
               be enabled with -listen tcp.  This option may be issued
               multiple times to enable listening to different transport

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

       -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 server 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 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).

               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 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.

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

       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

       -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.

               64|128|256|512 Set the maximum number of clients allowed to
               connect to the X server.  Acceptable values are 64, 128, 256 or

       -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

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

               disables smart scheduling on platforms that support the smart

       -schedInterval interval
               sets the smart scheduler's scheduling interval to interval

       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

               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 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

       -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-specific options.  This option sets that
               value, by default it is "MIT-unspecified" (not a very useful

       -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.

       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 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.

       The X server supports client connections via a platform-dependent
       subset of the following transport types: TCP/IP, Unix Domain sockets,
       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.

       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
       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 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
       display number of the server.  Each line of the file should contain
       either an Internet hostname (e.g. expo.lcs.mit.edu) 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


       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

       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
       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 connection.  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

       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.

       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 recognize when connecting to the server is possible.

       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

       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.

       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 '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:


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

                                     Bitmap font directories

                                     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)

       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

       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 1.20.4                    XSERVER(1)