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Xorg - X11R7 X server
Xorg [:display] [option ...]
Xorg is a full featured X server that was originally designed for UNIX
and UNIX-like operating systems running on Intel x86 hardware. It now
runs on a wider range of hardware and OS platforms.
This work was derived by the X.Org Foundation from the XFree86
Project's XFree86 4.4rc2 release. The XFree86 release was originally
derived from X386 1.2 by Thomas Roell which was contributed to X11R5 by
Snitily Graphics Consulting Service.
Xorg operates under a wide range of operating systems and hardware
platforms. The Intel x86 (IA32) architecture is the most widely sup-
ported hardware platform. Other hardware platforms include Compaq
Alpha, Intel IA64, AMD64, SPARC and PowerPC. The most widely supported
operating systems are the free/OpenSource UNIX-like systems such as
Linux, FreeBSD, NetBSD, OpenBSD, and Solaris. Commercial UNIX operat-
ing systems such as UnixWare are also supported. Other supported oper-
ating systems include GNU Hurd. Mac OS X is supported with the
Xquartz(1) X server. Win32/Cygwin is supported with the XWin(1) X
Xorg supports connections made using the following reliable byte-
On most platforms, the "Local" connection type is a UNIX-domain
socket. On some System V platforms, the "local" connection types
also include STREAMS pipes, named pipes, and some other mechanisms.
Xorg listens on port 6000+n, where n is the display number. This
connection type can be disabled with the -nolisten option (see the
Xserver(1) man page for details).
For operating systems that support local connections other than Unix
Domain sockets (SVR3 and SVR4), there is a compiled-in list specifying
the order in which local connections should be attempted. This list
can be overridden by the XLOCAL environment variable described below.
If the display name indicates a best-choice connection should be made
(e.g. :0.0), each connection mechanism is tried until a connection
succeeds or no more mechanisms are available. Note: for these OSs, the
Unix Domain socket connection is treated differently from the other
local connection types. To use it the connection must be made to
The XLOCAL environment variable should contain a list of one more more
of the following:
which represent SVR4 Named Streams pipe, Old-style USL Streams pipe,
SCO XSight Streams pipe, and ISC Streams pipe, respectively. You can
select a single mechanism (e.g. XLOCAL=NAMED), or an ordered list
(e.g. XLOCAL="NAMED:PTS:SCO"). his variable overrides the compiled-in
defaults. For SVR4 it is recommended that NAMED be the first prefer-
ence connection. The default setting is PTS:NAMED:ISC:SCO.
To globally override the compiled-in defaults, you should define (and
export if using sh or ksh) XLOCAL globally. If you use startx(1) or
xinit(1), the definition should be at the top of your .xinitrc file.
If you use xdm(1), the definitions should be early on in the
Xorg supports several mechanisms for supplying/obtaining configuration
and run-time parameters: command line options, environment variables,
the xorg.conf(5) configuration files, auto-detection, and fallback
defaults. When the same information is supplied in more than one way,
the highest precedence mechanism is used. The list of mechanisms is
ordered from highest precedence to lowest. Note that not all parame-
ters can be supplied via all methods. The available command line
options and environment variables (and some defaults) are described
here and in the Xserver(1) manual page. Most configuration file param-
eters, with their defaults, are described in the xorg.conf(5) manual
page. Driver and module specific configuration parameters are
described in the relevant driver or module manual page.
In addition to the normal server options described in the Xserver(1)
manual page, Xorg accepts the following command line switches:
vtXX XX specifies the Virtual Terminal device number which Xorg will
use. Without this option, Xorg will pick the first available
Virtual Terminal that it can locate. This option applies only
to platforms that have virtual terminal support, such as Linux,
BSD, OpenSolaris, SVR3, and SVR4.
Allow the server to start up even if the mouse device can't be
opened or initialised. This is equivalent to the Allow-
MouseOpenFail xorg.conf(5) file option.
Make the VidMode extension available to remote clients. This
allows the xvidtune client to connect from another host. This
is equivalent to the AllowNonLocalXvidtune xorg.conf(5) file
option. By default non-local connections are not allowed.
Set the blue gamma correction. value must be between 0.1 and
10. The default is 1.0. Not all drivers support this. See
also the -gamma, -rgamma, and -ggamma options.
-bpp n No longer supported. Use -depth to set the color depth, and
use -fbbpp if you really need to force a non-default frame-
buffer (hardware) pixel format.
Read the server configuration from file. This option will work
for any file when the server is run as root (i.e, with real-uid
0), or for files relative to a directory in the config search
path for all other users.
Read the server configuration files from directory. This
option will work for any directory when the server is run as
root (i.e, with real-uid 0), or for directories relative to a
directory in the config directory search path for all other
When this option is specified, the Xorg server loads all video
driver modules, probes for available hardware, and writes out
an initial xorg.conf(5) file based on what was detected. This
option currently has some problems on some platforms, but in
most cases it is a good way to bootstrap the configuration
process. This option is only available when the server is run
as root (i.e, with real-uid 0).
SCO only. This is the same as the vt option, and is provided
for compatibility with the native SCO X server.
Sets the default color depth. Legal values are 1, 4, 8, 15,
16, and 24. Not all drivers support all values.
Disable the parts of the VidMode extension (used by the xvid-
tune client) that can be used to change the video modes. This
is equivalent to the DisableVidModeExtension xorg.conf(5) file
Sets the number of framebuffer bits per pixel. You should only
set this if you're sure it's necessary; normally the server can
deduce the correct value from -depth above. Useful if you want
to run a depth 24 configuration with a 24 bpp framebuffer
rather than the (possibly default) 32 bpp framebuffer (or vice
versa). Legal values are 1, 8, 16, 24, 32. Not all drivers
support all values.
Swap the default values for the black and white pixels.
Set the gamma correction. value must be between 0.1 and 10.
The default is 1.0. This value is applied equally to the R, G
and B values. Those values can be set independently with the
-rgamma, -bgamma, and -ggamma options. Not all drivers support
Set the green gamma correction. value must be between 0.1 and
10. The default is 1.0. Not all drivers support this. See
also the -gamma, -rgamma, and -bgamma options.
The Xorg server checks the ABI revision levels of each module
that it loads. It will normally refuse to load modules with
ABI revisions that are newer than the server's. This is
because such modules might use interfaces that the server does
not have. When this option is specified, mismatches like this
are downgraded from fatal errors to warnings. This option
should be used with care.
Restrict device resets to the device at bus-id. The bus-id
string has the form bustype:bus:device:function (e.g.,
`PCI:1:0:0'). At present, only isolation of PCI devices is
supported; i.e., this option is ignored if bustype is anything
other than `PCI'.
Prevent the server from detaching its initial controlling ter-
minal. This option is only useful when debugging the server.
Not all platforms support (or can use) this option.
Use the xorg.conf(5) file InputDevice section called keyboard-
name as the core keyboard. This option is ignored when the
Layout section specifies a core keyboard. In the absence of
both a Layout section and this option, the first relevant
InputDevice section is used for the core keyboard.
Use the xorg.conf(5) file Layout section called layout-name.
By default the first Layout section is used.
Use the file called filename as the Xorg server log file. The
default log file is /var/log/Xorg.n.log on most platforms,
where n is the display number of the Xorg server. The default
may be in a different directory on some platforms. This option
is only available when the server is run as root (i.e, with
Sets the verbosity level for information printed to the Xorg
server log file. If the n value isn't supplied, each occur-
rence of this option increments the log file verbosity level.
When the n value is supplied, the log file verbosity level is
set to that value. The default log file verbosity level is 3.
Set the module search path to searchpath. searchpath is a
comma separated list of directories to search for Xorg server
modules. This option is only available when the server is run
as root (i.e, with real-uid 0).
-nosilk Disable Silken Mouse support.
Set the internal pixmap format for depth 24 pixmaps to 24 bits
per pixel. The default is usually 32 bits per pixel. There is
normally little reason to use this option. Some client appli-
cations don't like this pixmap format, even though it is a per-
fectly legal format. This is equivalent to the Pixmap
xorg.conf(5) file option.
Set the internal pixmap format for depth 24 pixmaps to 32 bits
per pixel. This is usually the default. This is equivalent to
the Pixmap xorg.conf(5) file option.
Use the xorg.conf(5) file InputDevice section called pointer-
name as the core pointer. This option is ignored when the Lay-
out section specifies a core pointer. In the absence of both a
Layout section and this option, the first relevant InputDevice
section is used for the core pointer.
-quiet Suppress most informational messages at startup. The verbosity
level is set to zero.
Set the red gamma correction. value must be between 0.1 and
10. The default is 1.0. Not all drivers support this. See
also the -gamma, -bgamma, and -ggamma options.
Use the xorg.conf(5) file Screen section called screen-name.
By default the screens referenced by the default Layout section
are used, or the first Screen section when there are no Layout
This is the same as the -version option, and is included for
compatibility reasons. It may be removed in a future release,
so the -version option should be used instead.
Print out the default module path the server was compiled with.
Print out the path libraries should be installed to.
For each driver module installed, print out the list of options
and their argument types.
Set RGB weighting at 16 bpp. The default is 565. This applies
only to those drivers which support 16 bpp.
Sets the verbosity level for information printed on stderr. If
the n value isn't supplied, each occurrence of this option
increments the verbosity level. When the n value is supplied,
the verbosity level is set to that value. The default ver-
bosity level is 0.
Print out the server version, patchlevel, release date, the
operating system/platform it was built on, and whether it
includes module loader support.
The Xorg server is normally configured to recognize various special
combinations of key presses that instruct the server to perform some
action, rather than just sending the key press event to a client appli-
cation. These actions depend on the XKB keymap loaded by a particular
keyboard device and may or may not be available on a given configura-
The following key combinations are commonly part of the default XKEY-
Immediately kills the server -- no questions asked. It can be
disabled by setting the DontZap xorg.conf(5) file option to a
It should be noted that zapping is triggered by the Termi-
nate_Server action in the keyboard map. This action is not part
of the default keymaps but can be enabled with the XKB option
Change video mode to next one specified in the configuration
file. This can be disabled with the DontZoom xorg.conf(5) file
Change video mode to previous one specified in the configura-
tion file. This can be disabled with the DontZoom xorg.conf(5)
For systems with virtual terminal support, these keystroke com-
binations are used to switch to virtual terminals 1 through 12,
respectively. This can be disabled with the DontVTSwitch
xorg.conf(5) file option.
Xorg typically uses a configuration file called xorg.conf and configu-
ration files with the suffix .conf in a directory called __xconfigdir__
for its initial setup. Refer to the xorg.conf(5) manual page for
information about the format of this file.
Xorg has a mechanism for automatically generating a built-in configura-
tion at run-time when no xorg.conf file or __xconfigdir__ files are
present. The current version of this automatic configuration mechanism
works in two ways.
The first is via enhancements that have made many components of the
xorg.conf file optional. This means that information that can be
probed or reasonably deduced doesn't need to be specified explicitly,
greatly reducing the amount of built-in configuration information that
needs to be generated at run-time.
The second is to have "safe" fallbacks for most configuration informa-
tion. This maximises the likelihood that the Xorg server will start up
in some usable configuration even when information about the specific
hardware is not available.
The automatic configuration support for Xorg is work in progress. It
is currently aimed at the most popular hardware and software platforms
supported by Xorg. Enhancements are planned for future releases.
The Xorg server config files can be found in a range of locations.
These are documented fully in the xorg.conf(5) manual page. The most
commonly used locations are shown here.
/etc/X11/xorg.conf Server configuration file.
/etc/X11/xorg.conf-4 Server configuration file.
/etc/xorg.conf Server configuration file.
/usr/X11R7/etc/xorg.conf Server configuration file.
/usr/X11R7/lib/X11/xorg.conf Server configuration file.
/etc/X11/__xconfigdir__ Server configuration directory.
/etc/X11/__xconfigdir__-4 Server configuration directory.
/etc/__xconfigdir__ Server configuration directory.
/usr/X11R7/etc/__xconfigdir__ Server configuration directory.
Server configuration directory.
/var/log/Xorg.n.log Server log file for display n.
/usr/X11R7/bin/* Client binaries.
/usr/X11R7/include/* Header files.
/usr/X11R7/share/X11/XErrorDB Client error message database.
Client resource specifications.
/usr/X11R7/man/man?/* Manual pages.
/etc/Xn.hosts Initial access control list for display
X(7), Xserver(1), xdm(1), xinit(1), xorg.conf(5), xvidtune(1), apm(4),
ati(4), chips(4), cirrus(4), cyrix(4), fbdev(4), glide(4), glint(4),
i128(4), i740(4), imstt(4), intel(4), mga(4), neomagic(4), nsc(4),
nv(4), openchrome (4), r128(4), rendition(4), s3virge(4), siliconmotion(4)
, sis(4), sunbw2(4), suncg14(4), suncg3(4), suncg6(4),
sunffb(4), sunleo(4), suntcx(4), tdfx(4), tga(4), trident(4), tseng(4),
v4l(4), vesa(4), vmware(4),
Web site <http://www.x.org>.
Xorg has many contributors world wide. The names of most of them can
be found in the documentation, ChangeLog files in the source tree, and
in the actual source code.
Xorg was originally based on XFree86 4.4rc2. That was originally based
on X386 1.2 by Thomas Roell, which was contributed to the then X Con-
sortium's X11R5 distribution by SGCS.
Xorg is released by the X.Org Foundation.
The project that became XFree86 was originally founded in 1992 by David
Dawes, Glenn Lai, Jim Tsillas and David Wexelblat.
XFree86 was later integrated in the then X Consortium's X11R6 release
by a group of dedicated XFree86 developers, including the following:
Stuart Anderson firstname.lastname@example.org
Doug Anson email@example.com
Gertjan Akkerman firstname.lastname@example.org
Mike Bernson email@example.com
Robin Cutshaw robin@XFree86.org
David Dawes dawes@XFree86.org
Marc Evans marc@XFree86.org
Pascal Haible firstname.lastname@example.org
Matthieu Herrb Matthieu.Herrb@laas.fr
Dirk Hohndel hohndel@XFree86.org
David Holland email@example.com
Alan Hourihane firstname.lastname@example.org
Jeffrey Hsu email@example.com
Glenn Lai firstname.lastname@example.org
Ted Lemon email@example.com
Rich Murphey rich@XFree86.org
Hans Nasten firstname.lastname@example.org
Mark Snitily email@example.com
Randy Terbush firstname.lastname@example.org
Jon Tombs tombs@XFree86.org
Kees Verstoep email@example.com
Paul Vixie firstname.lastname@example.org
Mark Weaver Mark_Weaver@brown.edu
David Wexelblat dwex@XFree86.org
Philip Wheatley Philip.Wheatley@ColumbiaSC.NCR.COM
Thomas Wolfram email@example.com
Orest Zborowski firstname.lastname@example.org
Xorg source is available from the FTP server <ftp://ftp.x.org/>, and
from the X.Org server <http://gitweb.freedesktop.org/>. Documentation
and other information can be found from the X.Org web site
Xorg is copyright software, provided under licenses that permit modifi-
cation and redistribution in source and binary form without fee. Xorg
is copyright by numerous authors and contributors from around the
world. Licensing information can be found at <http://www.x.org>.
Refer to the source code for specific copyright notices.
XFree86(TM) is a trademark of The XFree86 Project, Inc.
X11(TM) and X Window System(TM) are trademarks of The Open Group.
X Version 11 Xorg(1)