1XSERVER(1) General Commands Manual XSERVER(1)
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6 Xserver - X Window System display server
7
9 X [option ...]
10
12 X is the generic name for the X Window System display server. It is
13 frequently a link or a copy of the appropriate server binary for driv‐
14 ing the most frequently used server on a given machine.
15
17 The X server is usually started from the X Display Manager program
18 xdm(1) or a similar display manager program. This utility is run from
19 the system boot files and takes care of keeping the server running,
20 prompting for usernames and passwords, and starting up the user ses‐
21 sions.
22 Installations that run more than one window system may need to use the
24 xinit(1) utility instead of a display manager. However, xinit is to be
25 considered a tool for building startup scripts and is not intended for
26 use by end users. Site administrators are strongly urged to use a dis‐
27 play manager, or build other interfaces for novice users.
28 The X server may also be started directly by the user, though this
30 method is usually reserved for testing and is not recommended for nor‐
31 mal operation. On some platforms, the user must have special permis‐
32 sion to start the X server, often because access to certain devices
33 (e.g. /dev/mouse) is restricted.
34 When the X server starts up, it typically takes over the display. If
36 you are running on a workstation whose console is the display, you may
37 not be able to log into the console while the server is running.
38
40 Many X servers have device-specific command line options. See the man‐
41 ual pages for the individual servers for more details; a list of
42 server-specific manual pages is provided in the SEE ALSO section below.
43 All of the X servers accept the command line options described below.
45 Some X servers may have alternative ways of providing the parameters
46 described here, but the values provided via the command line options
47 should override values specified via other mechanisms.
48 :displaynumber
50 The X server runs as the given displaynumber, which by default
51 is 0. If multiple X servers are to run simultaneously on a
52 host, each must have a unique display number. See the DISPLAY
53 NAMES section of the X(7) manual page to learn how to specify
54 which display number clients should try to use.
55 -a number
57 sets pointer acceleration (i.e. the ratio of how much is re‐
58 ported to how much the user actually moved the pointer).
59 -ac disables host-based access control mechanisms. Enables access
61 by any host, and permits any host to modify the access control
62 list. Use with extreme caution. This option exists primarily
63 for running test suites remotely.
64 -audit level
66 sets the audit trail level. The default level is 1, meaning
67 only connection rejections are reported. Level 2 additionally
68 reports all successful connections and disconnects. Level 4
69 enables messages from the SECURITY extension, if present, in‐
70 cluding generation and revocation of authorizations and viola‐
71 tions of the security policy. Level 0 turns off the audit
72 trail. Audit lines are sent as standard error output.
73 -auth authorization-file
75 specifies a file which contains a collection of authorization
76 records used to authenticate access. See also the xdm(1) and
77 Xsecurity(7) manual pages.
78 -background none
80 Asks the driver not to clear the background on startup, if the
81 driver supports that. May be useful for smooth transition with
82 eg. fbdev driver. For security reasons this is not the default
83 as the screen contents might show a previous user session.
84 -br sets the default root window to solid black instead of the
86 standard root weave pattern. This is the default unless
87 -retro or -wr is specified.
88 -bs disables backing store support on all screens.
90 -c turns off key-click.
92 c volume
94 sets key-click volume (allowable range: 0-100).
95 -cc class
97 sets the visual class for the root window of color screens.
98 The class numbers are as specified in the X protocol. Not
99 obeyed by all servers.
100 -core causes the server to generate a core dump on fatal errors.
102 -displayfd fd
104 specifies a file descriptor in the launching process. Rather
105 than specify a display number, the X server will attempt to
106 listen on successively higher display numbers, and upon finding
107 a free one, will write the display number back on this file de‐
108 scriptor as a newline-terminated string. The -pn option is ig‐
109 nored when using -displayfd.
110 -deferglyphs whichfonts
112 specifies the types of fonts for which the server should at‐
113 tempt to use deferred glyph loading. whichfonts can be all
114 (all fonts), none (no fonts), or 16 (16 bit fonts only).
115 -dpi resolution
117 sets the resolution for all screens, in dots per inch. To be
118 used when the server cannot determine the screen size(s) from
119 the hardware.
120 dpms enables DPMS (display power management services), where sup‐
122 ported. The default state is platform and configuration spe‐
123 cific.
124 -dpms disables DPMS (display power management services). The default
126 state is platform and configuration specific.
127 -extensionextensionName
129 disables named extension. If an unknown extension name is
130 specified, a list of accepted extension names is printed.
131 +extensionextensionName
133 enables named extension. If an unknown extension name is
134 specified, a list of accepted extension names is printed.
135 -f volume
137 sets beep (bell) volume (allowable range: 0-100).
138 -fc cursorFont
140 sets default cursor font.
141 -fn font
143 sets the default font.
144 -fakescreenfps ps
146 sets fake presenter screen default fps (allowable range:
147 1-600).
148 -fp fontPath
150 sets the search path for fonts. This path is a comma separated
151 list of directories which the X server searches for font data‐
152 bases. See the FONTS section of this manual page for more in‐
153 formation and the default list.
154 -help prints a usage message.
156 -I causes all remaining command line arguments to be ignored.
158 -iglx Prohibit creating indirect GLX contexts. Indirect GLX is of
160 limited use, since it lacks support for many modern OpenGL fea‐
161 tures and extensions; it's slower than direct contexts; and it
162 opens a large attack surface for protocol parsing errors. This
163 is the default unless +iglx is specified.
164 +iglx Allow creating indirect GLX contexts.
166 -maxbigreqsize size
168 sets the maximum big request to size MB.
169 -nocursor
171 disable the display of the pointer cursor.
172 -nolisten trans-type
174 disables a transport type. For example, TCP/IP connections can
175 be disabled with -nolisten tcp. This option may be issued mul‐
176 tiple times to disable listening to different transport types.
177 Supported transport types are platform dependent, but commonly
178 include:
179 tcp TCP over IPv4 or IPv6
181 inet TCP over IPv4 only
182 inet6 TCP over IPv6 only
183 unix UNIX Domain Sockets
184 local Platform preferred local connection method
185 -listen trans-type
187 enables a transport type. For example, TCP/IP connections can
188 be enabled with -listen tcp. This option may be issued multi‐
189 ple times to enable listening to different transport types.
190 -noreset
192 prevents a server reset when the last client connection is
193 closed. This overrides a previous -terminate command line op‐
194 tion.
195 -p minutes
197 sets screen-saver pattern cycle time in minutes.
198 -pn permits the server to continue running if it fails to establish
200 all of its well-known sockets (connection points for clients),
201 but establishes at least one. This option is set by default.
202 -nopn causes the server to exit if it fails to establish all of its
204 well-known sockets (connection points for clients).
205 -r turns off auto-repeat.
207 r turns on auto-repeat.
209 -retro starts the server with the classic stipple and cursor visible.
211 The default is to start with a black root window, and to sup‐
212 press display of the cursor until the first time an application
213 calls XDefineCursor(). For kdrive servers, this implies -zap.
214 -s minutes
216 sets screen-saver timeout time in minutes.
217 -su disables save under support on all screens.
219 -seat seat
221 seat to run on. Takes a string identifying a seat in a platform
222 specific syntax. On platforms which support this feature this
223 may be used to limit the server to expose only a specific sub‐
224 set of devices connected to the system.
225 -t number
227 sets pointer acceleration threshold in pixels (i.e. after how
228 many pixels pointer acceleration should take effect).
229 -terminate
231 causes the server to terminate at server reset, instead of con‐
232 tinuing to run. This overrides a previous -noreset command
233 line option.
234 -to seconds
236 sets default connection timeout in seconds.
237 -tst disables all testing extensions (e.g., XTEST, XTrap, XTestEx‐
239 tension1, RECORD).
240 ttyxx ignored, for servers started the ancient way (from init).
242 v sets video-off screen-saver preference.
244 -v sets video-on screen-saver preference.
246 -wm forces the default backing-store of all windows to be When‐
248 Mapped. This is a backdoor way of getting backing-store to ap‐
249 ply to all windows. Although all mapped windows will have
250 backing store, the backing store attribute value reported by
251 the server for a window will be the last value established by a
252 client. If it has never been set by a client, the server will
253 report the default value, NotUseful. This behavior is required
254 by the X protocol, which allows the server to exceed the
255 client's backing store expectations but does not provide a way
256 to tell the client that it is doing so.
257 -wr sets the default root window to solid white instead of the
259 standard root weave pattern.
260 -x extension
262 loads the specified extension at init. This is a no-op for
263 most implementations.
264 [+-]xinerama
266 enables(+) or disables(-) the XINERAMA extension. The default
267 state is platform and configuration specific.
268
270 Some X servers accept the following options:
271 -ld kilobytes
273 sets the data space limit of the server to the specified number
274 of kilobytes. A value of zero makes the data size as large as
275 possible. The default value of -1 leaves the data space limit
276 unchanged.
277 -lf files
279 sets the number-of-open-files limit of the server to the speci‐
280 fied number. A value of zero makes the limit as large as pos‐
281 sible. The default value of -1 leaves the limit unchanged.
282 -ls kilobytes
284 sets the stack space limit of the server to the specified num‐
285 ber of kilobytes. A value of zero makes the stack size as
286 large as possible. The default value of -1 leaves the stack
287 space limit unchanged.
288 -maxclients
290 64|128|256|512 Set the maximum number of clients allowed to
291 connect to the X server. Acceptable values are 64, 128, 256 or
292 512.
293 -render default|mono|gray|color sets the color allocation policy that
295 will be used by the render extension.
296 default selects the default policy defined for the display
298 depth of the X server.
299 mono don't use any color cell.
301 gray use a gray map of 13 color cells for the X render ex‐
303 tension.
304 color use a color cube of at most 4*4*4 colors (that is 64
306 color cells).
307 -dumbSched
309 disables smart scheduling on platforms that support the smart
310 scheduler.
311 -schedInterval interval
313 sets the smart scheduler's scheduling interval to interval mil‐
314 liseconds.
315
317 X servers that support XDMCP have the following options. See the X
318 Display Manager Control Protocol specification for more information.
319 -query hostname
321 enables XDMCP and sends Query packets to the specified host‐
322 name.
323 -broadcast
325 enable XDMCP and broadcasts BroadcastQuery packets to the net‐
326 work. The first responding display manager will be chosen for
327 the session.
328 -multicast [address [hop count]]
330 Enable XDMCP and multicast BroadcastQuery packets to the net‐
331 work. The first responding display manager is chosen for the
332 session. If an address is specified, the multicast is sent to
333 that address. If no address is specified, the multicast is
334 sent to the default XDMCP IPv6 multicast group. If a hop count
335 is specified, it is used as the maximum hop count for the mul‐
336 ticast. If no hop count is specified, the multicast is set to
337 a maximum of 1 hop, to prevent the multicast from being routed
338 beyond the local network.
339 -indirect hostname
341 enables XDMCP and send IndirectQuery packets to the specified
342 hostname.
343 -port port-number
345 uses the specified port-number for XDMCP packets, instead of
346 the default. This option must be specified before any -query,
347 -broadcast, -multicast, or -indirect options.
348 -from local-address
350 specifies the local address to connect from (useful if the con‐
351 necting host has multiple network interfaces). The local-ad‐
352 dress may be expressed in any form acceptable to the host plat‐
353 form's gethostbyname(3) implementation.
354 -once causes the server to terminate (rather than reset) when the
356 XDMCP session ends.
357 -class display-class
359 XDMCP has an additional display qualifier used in resource
360 lookup for display-specific options. This option sets that
361 value, by default it is "MIT-unspecified" (not a very useful
362 value).
363 -cookie xdm-auth-bits
365 When testing XDM-AUTHENTICATION-1, a private key is shared be‐
366 tween the server and the manager. This option sets the value
367 of that private data (not that it is very private, being on the
368 command line!).
369 -displayID display-id
371 Yet another XDMCP specific value, this one allows the display
372 manager to identify each display so that it can locate the
373 shared key.
374
376 X servers that support the XKEYBOARD (a.k.a. "XKB") extension accept
377 the following options. All layout files specified on the command line
378 must be located in the XKB base directory or a subdirectory, and speci‐
379 fied as the relative path from the XKB base directory. The default XKB
380 base directory is /usr/lib/X11/xkb.
381 [+-]accessx [ timeout [ timeout_mask [ feedback [ options_mask ] ] ] ]
383 enables(+) or disables(-) AccessX key sequences.
384 -xkbdir directory
386 base directory for keyboard layout files. This option is not
387 available for setuid X servers (i.e., when the X server's real
388 and effective uids are different).
389 -ardelay milliseconds
391 sets the autorepeat delay (length of time in milliseconds that
392 a key must be depressed before autorepeat starts).
393 -arinterval milliseconds
395 sets the autorepeat interval (length of time in milliseconds
396 that should elapse between autorepeat-generated keystrokes).
397 -xkbmap filename
399 loads keyboard description in filename on server startup.
400
402 The X server supports client connections via a platform-dependent sub‐
403 set of the following transport types: TCP/IP, Unix Domain sockets, and
404 several varieties of SVR4 local connections. See the DISPLAY NAMES
405 section of the X(7) manual page to learn how to specify which transport
406 type clients should try to use.
407
409 The X server implements a platform-dependent subset of the following
410 authorization protocols: MIT-MAGIC-COOKIE-1, XDM-AUTHORIZATION-1, XDM-
411 AUTHORIZATION-2, SUN-DES-1, and MIT-KERBEROS-5. See the Xsecurity(7)
412 manual page for information on the operation of these protocols.
413 Authorization data required by the above protocols is passed to the
415 server in a private file named with the -auth command line option.
416 Each time the server is about to accept the first connection after a
417 reset (or when the server is starting), it reads this file. If this
418 file contains any authorization records, the local host is not automat‐
419 ically allowed access to the server, and only clients which send one of
420 the authorization records contained in the file in the connection setup
421 information will be allowed access. See the Xau manual page for a de‐
422 scription of the binary format of this file. See xauth(1) for mainte‐
423 nance of this file, and distribution of its contents to remote hosts.
424 The X server also uses a host-based access control list for deciding
426 whether or not to accept connections from clients on a particular ma‐
427 chine. If no other authorization mechanism is being used, this list
428 initially consists of the host on which the server is running as well
429 as any machines listed in the file /etc/Xn.hosts, where n is the dis‐
430 play number of the server. Each line of the file should contain either
431 an Internet hostname (e.g. expo.lcs.mit.edu) or a complete name in the
432 format family:name as described in the xhost(1) manual page. There
433 should be no leading or trailing spaces on any lines. For example:
434 joesworkstation
436 corporate.company.com
437 inet:bigcpu
438 local:
439 Users can add or remove hosts from this list and enable or disable ac‐
441 cess control using the xhost command from the same machine as the
442 server.
443 If the X FireWall Proxy (xfwp) is being used without a sitepolicy,
445 host-based authorization must be turned on for clients to be able to
446 connect to the X server via the xfwp. If xfwp is run without a config‐
447 uration file and thus no sitepolicy is defined, if xfwp is using an X
448 server where xhost + has been run to turn off host-based authorization
449 checks, when a client tries to connect to this X server via xfwp, the X
450 server will deny the connection. See xfwp(1) for more information
451 about this proxy.
452 The X protocol intrinsically does not have any notion of window opera‐
454 tion permissions or place any restrictions on what a client can do; if
455 a program can connect to a display, it has full run of the screen. X
456 servers that support the SECURITY extension fare better because clients
457 can be designated untrusted via the authorization they use to connect;
458 see the xauth(1) manual page for details. Restrictions are imposed on
459 untrusted clients that curtail the mischief they can do. See the SECU‐
460 RITY extension specification for a complete list of these restrictions.
461 Sites that have better authentication and authorization systems might
463 wish to make use of the hooks in the libraries and the server to pro‐
464 vide additional security models.
465
467 The X server attaches special meaning to the following signals:
468 SIGHUP This signal causes the server to close all existing connec‐
470 tions, free all resources, and restore all defaults. It is
471 sent by the display manager whenever the main user's main ap‐
472 plication (usually an xterm or window manager) exits to force
473 the server to clean up and prepare for the next user.
474 SIGTERM This signal causes the server to exit cleanly.
476 SIGUSR1 This signal is used quite differently from either of the above.
478 When the server starts, it checks to see if it has inherited
479 SIGUSR1 as SIG_IGN instead of the usual SIG_DFL. In this case,
480 the server sends a SIGUSR1 to its parent process after it has
481 set up the various connection schemes. Xdm uses this feature
482 to recognize when connecting to the server is possible.
483
485 The X server can obtain fonts from directories and/or from font
486 servers. The list of directories and font servers the X server uses
487 when trying to open a font is controlled by the font path.
488 The default font path is catalogue:/etc/X11/fontpath.d,built-ins .
490 A special kind of directory can be specified using the catalogue: pre‐
492 fix. Directories specified this way can contain symlinks pointing to
493 the real font directories. See the FONTPATH.D section for details.
494 The font path can be set with the -fp option or by xset(1) after the
496 server has started.
497
499 You can specify a special kind of font path in the form cata‐
500 logue:<dir>. The directory specified after the catalogue: prefix will
501 be scanned for symlinks and each symlink destination will be added as a
502 local fontfile FPE.
503 The symlink can be suffixed by attributes such as 'unscaled', which
505 will be passed through to the underlying fontfile FPE. The only excep‐
506 tion is the newly introduced 'pri' attribute, which will be used for
507 ordering the font paths specified by the symlinks.
508 An example configuration:
510 75dpi:unscaled:pri=20 -> /usr/share/X11/fonts/75dpi
512 ghostscript:pri=60 -> /usr/share/fonts/default/ghostscript
513 misc:unscaled:pri=10 -> /usr/share/X11/fonts/misc
514 type1:pri=40 -> /usr/share/X11/fonts/Type1
515 type1:pri=50 -> /usr/share/fonts/default/Type1
516 This will add /usr/share/X11/fonts/misc as the first FPE with the at‐
518 tribute 'unscaled', second FPE will be /usr/share/X11/fonts/75dpi, also
519 with the attribute 'unscaled' etc. This is functionally equivalent to
520 setting the following font path:
521 /usr/share/X11/fonts/misc:unscaled,
523 /usr/share/X11/fonts/75dpi:unscaled,
524 /usr/share/X11/fonts/Type1,
525 /usr/share/fonts/default/Type1,
526 /usr/share/fonts/default/ghostscript
527
530 /etc/Xn.hosts Initial access control list for display
531 number n
532 /usr/share/fonts/X11/misc,/usr/share/fonts/X11/75dpi,/usr/share/fonts/X11/100dpi
534 Bitmap font directories
535 /usr/share/fonts/X11/TTF,/usr/share/fonts/X11/Type1
537 Outline font directories
538 /tmp/.X11-unix/Xn Unix domain socket for display number n
540 /usr/adm/Xnmsgs Error log file for display number n if
542 run from init(8)
543 /usr/lib/X11/xdm/xdm-errors Default error log file if the server is
545 run from xdm(1)
546
548 General information: X(7)
549 Protocols: X Window System Protocol, The X Font Service Protocol, X
551 Display Manager Control Protocol
552 Fonts: bdftopcf(1), mkfontdir(1), mkfontscale(1), xfs(1), xlsfonts(1),
554 xfontsel(1), xfd(1), X Logical Font Description Conventions
555 Keyboards: xkeyboard-config(7)
557 Security: Xsecurity(7), xauth(1), Xau(1), xdm(1), xhost(1), xfwp(1),
559 Security Extension Specification
560 Starting the server: startx(1), xdm(1), xinit(1)
562 Controlling the server once started: xset(1), xsetroot(1), xhost(1),
564 xinput(1), xrandr(1)
565 Server-specific man pages: Xorg(1), Xdmx(1), Xephyr(1), Xnest(1),
567 Xvfb(1), Xquartz(1), XWin(1).
568 Server internal documentation: Definition of the Porting Layer for the
570 X v11 Sample Server
571
573 The sample server was originally written by Susan Angebranndt, Raymond
574 Drewry, Philip Karlton, and Todd Newman, from Digital Equipment Corpo‐
575 ration, with support from a large cast. It has since been extensively
576 rewritten by Keith Packard and Bob Scheifler, from MIT. Dave Wiggins
577 took over post-R5 and made substantial improvements.
578X Version 11 xorg-server 1.20.14 XSERVER(1)