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
58 reported 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,
70 including generation and revocation of authorizations and vio‐
71 lations 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
108 descriptor as a newline-terminated string. The -pn option is
109 ignored when using -displayfd.
110 -deferglyphs whichfonts
112 specifies the types of fonts for which the server should
113 attempt 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 -fp fontPath
146 sets the search path for fonts. This path is a comma separated
147 list of directories which the X server searches for font data‐
148 bases. See the FONTS section of this manual page for more
149 information and the default list.
150 -help prints a usage message.
152 -I causes all remaining command line arguments to be ignored.
154 -iglx Prohibit creating indirect GLX contexts. Indirect GLX is of
156 limited use, since it lacks support for many modern OpenGL fea‐
157 tures and extensions; it's slower than direct contexts; and it
158 opens a large attack surface for protocol parsing errors. This
159 is the default unless +iglx is specified.
160 +iglx Allow creating indirect GLX contexts.
162 -maxbigreqsize size
164 sets the maximum big request to size MB.
165 -nocursor
167 disable the display of the pointer cursor.
168 -nolisten trans-type
170 disables a transport type. For example, TCP/IP connections can
171 be disabled with -nolisten tcp. This option may be issued mul‐
172 tiple times to disable listening to different transport types.
173 Supported transport types are platform dependent, but commonly
174 include:
175 tcp TCP over IPv4 or IPv6
177 inet TCP over IPv4 only
178 inet6 TCP over IPv6 only
179 unix UNIX Domain Sockets
180 local Platform preferred local connection method
181 -listen trans-type
183 enables a transport type. For example, TCP/IP connections can
184 be enabled with -listen tcp. This option may be issued multi‐
185 ple times to enable listening to different transport types.
186 -noreset
188 prevents a server reset when the last client connection is
189 closed. This overrides a previous -terminate command line
190 option.
191 -p minutes
193 sets screen-saver pattern cycle time in minutes.
194 -pn permits the server to continue running if it fails to establish
196 all of its well-known sockets (connection points for clients),
197 but establishes at least one. This option is set by default.
198 -nopn causes the server to exit if it fails to establish all of its
200 well-known sockets (connection points for clients).
201 -r turns off auto-repeat.
203 r turns on auto-repeat.
205 -retro starts the server with the classic stipple and cursor visible.
207 The default is to start with a black root window, and to sup‐
208 press display of the cursor until the first time an application
209 calls XDefineCursor(). For kdrive servers, this implies -zap.
210 -s minutes
212 sets screen-saver timeout time in minutes.
213 -su disables save under support on all screens.
215 -seat seat
217 seat to run on. Takes a string identifying a seat in a platform
218 specific syntax. On platforms which support this feature this
219 may be used to limit the server to expose only a specific sub‐
220 set of devices connected to the system.
221 -t number
223 sets pointer acceleration threshold in pixels (i.e. after how
224 many pixels pointer acceleration should take effect).
225 -terminate
227 causes the server to terminate at server reset, instead of con‐
228 tinuing to run. This overrides a previous -noreset command
229 line option.
230 -to seconds
232 sets default connection timeout in seconds.
233 -tst disables all testing extensions (e.g., XTEST, XTrap, XTestEx‐
235 tension1, RECORD).
236 ttyxx ignored, for servers started the ancient way (from init).
238 v sets video-off screen-saver preference.
240 -v sets video-on screen-saver preference.
242 -wm forces the default backing-store of all windows to be When‐
244 Mapped. This is a backdoor way of getting backing-store to
245 apply to all windows. Although all mapped windows will have
246 backing store, the backing store attribute value reported by
247 the server for a window will be the last value established by a
248 client. If it has never been set by a client, the server will
249 report the default value, NotUseful. This behavior is required
250 by the X protocol, which allows the server to exceed the
251 client's backing store expectations but does not provide a way
252 to tell the client that it is doing so.
253 -wr sets the default root window to solid white instead of the
255 standard root weave pattern.
256 -x extension
258 loads the specified extension at init. This is a no-op for
259 most implementations.
260 [+-]xinerama
262 enables(+) or disables(-) the XINERAMA extension. The default
263 state is platform and configuration specific.
264
266 Some X servers accept the following options:
267 -ld kilobytes
269 sets the data space limit of the server to the specified number
270 of kilobytes. A value of zero makes the data size as large as
271 possible. The default value of -1 leaves the data space limit
272 unchanged.
273 -lf files
275 sets the number-of-open-files limit of the server to the speci‐
276 fied number. A value of zero makes the limit as large as pos‐
277 sible. The default value of -1 leaves the limit unchanged.
278 -ls kilobytes
280 sets the stack space limit of the server to the specified num‐
281 ber of kilobytes. A value of zero makes the stack size as
282 large as possible. The default value of -1 leaves the stack
283 space limit unchanged.
284 -maxclients
286 64|128|256|512 Set the maximum number of clients allowed to
287 connect to the X server. Acceptable values are 64, 128, 256 or
288 512.
289 -render default|mono|gray|color sets the color allocation policy that
291 will be used by the render extension.
292 default selects the default policy defined for the display
294 depth of the X server.
295 mono don't use any color cell.
297 gray use a gray map of 13 color cells for the X render
299 extension.
300 color use a color cube of at most 4*4*4 colors (that is 64
302 color cells).
303 -dumbSched
305 disables smart scheduling on platforms that support the smart
306 scheduler.
307 -schedInterval interval
309 sets the smart scheduler's scheduling interval to interval mil‐
310 liseconds.
311
313 X servers that support XDMCP have the following options. See the X
314 Display Manager Control Protocol specification for more information.
315 -query hostname
317 enables XDMCP and sends Query packets to the specified host‐
318 name.
319 -broadcast
321 enable XDMCP and broadcasts BroadcastQuery packets to the net‐
322 work. The first responding display manager will be chosen for
323 the session.
324 -multicast [address [hop count]]
326 Enable XDMCP and multicast BroadcastQuery packets to the net‐
327 work. The first responding display manager is chosen for the
328 session. If an address is specified, the multicast is sent to
329 that address. If no address is specified, the multicast is
330 sent to the default XDMCP IPv6 multicast group. If a hop count
331 is specified, it is used as the maximum hop count for the mul‐
332 ticast. If no hop count is specified, the multicast is set to
333 a maximum of 1 hop, to prevent the multicast from being routed
334 beyond the local network.
335 -indirect hostname
337 enables XDMCP and send IndirectQuery packets to the specified
338 hostname.
339 -port port-number
341 uses the specified port-number for XDMCP packets, instead of
342 the default. This option must be specified before any -query,
343 -broadcast, -multicast, or -indirect options.
344 -from local-address
346 specifies the local address to connect from (useful if the con‐
347 necting host has multiple network interfaces). The local-
348 address may be expressed in any form acceptable to the host
349 platform's gethostbyname(3) implementation.
350 -once causes the server to terminate (rather than reset) when the
352 XDMCP session ends.
353 -class display-class
355 XDMCP has an additional display qualifier used in resource
356 lookup for display-specific options. This option sets that
357 value, by default it is "MIT-unspecified" (not a very useful
358 value).
359 -cookie xdm-auth-bits
361 When testing XDM-AUTHENTICATION-1, a private key is shared
362 between the server and the manager. This option sets the value
363 of that private data (not that it is very private, being on the
364 command line!).
365 -displayID display-id
367 Yet another XDMCP specific value, this one allows the display
368 manager to identify each display so that it can locate the
369 shared key.
370
372 X servers that support the XKEYBOARD (a.k.a. "XKB") extension accept
373 the following options. All layout files specified on the command line
374 must be located in the XKB base directory or a subdirectory, and speci‐
375 fied as the relative path from the XKB base directory. The default XKB
376 base directory is /usr/lib/X11/xkb.
377 [+-]accessx [ timeout [ timeout_mask [ feedback [ options_mask ] ] ] ]
379 enables(+) or disables(-) AccessX key sequences.
380 -xkbdir directory
382 base directory for keyboard layout files. This option is not
383 available for setuid X servers (i.e., when the X server's real
384 and effective uids are different).
385 -ardelay milliseconds
387 sets the autorepeat delay (length of time in milliseconds that
388 a key must be depressed before autorepeat starts).
389 -arinterval milliseconds
391 sets the autorepeat interval (length of time in milliseconds
392 that should elapse between autorepeat-generated keystrokes).
393 -xkbmap filename
395 loads keyboard description in filename on server startup.
396
398 The X server supports client connections via a platform-dependent sub‐
399 set of the following transport types: TCP/IP, Unix Domain sockets, and
400 several varieties of SVR4 local connections. See the DISPLAY NAMES
401 section of the X(7) manual page to learn how to specify which transport
402 type clients should try to use.
403
405 The X server implements a platform-dependent subset of the following
406 authorization protocols: MIT-MAGIC-COOKIE-1, XDM-AUTHORIZATION-1, XDM-
407 AUTHORIZATION-2, SUN-DES-1, and MIT-KERBEROS-5. See the Xsecurity(7)
408 manual page for information on the operation of these protocols.
409 Authorization data required by the above protocols is passed to the
411 server in a private file named with the -auth command line option.
412 Each time the server is about to accept the first connection after a
413 reset (or when the server is starting), it reads this file. If this
414 file contains any authorization records, the local host is not automat‐
415 ically allowed access to the server, and only clients which send one of
416 the authorization records contained in the file in the connection setup
417 information will be allowed access. See the Xau manual page for a
418 description of the binary format of this file. See xauth(1) for main‐
419 tenance of this file, and distribution of its contents to remote hosts.
420 The X server also uses a host-based access control list for deciding
422 whether or not to accept connections from clients on a particular
423 machine. If no other authorization mechanism is being used, this list
424 initially consists of the host on which the server is running as well
425 as any machines listed in the file /etc/Xn.hosts, where n is the dis‐
426 play number of the server. Each line of the file should contain either
427 an Internet hostname (e.g. expo.lcs.mit.edu) or a complete name in the
428 format family:name as described in the xhost(1) manual page. There
429 should be no leading or trailing spaces on any lines. For example:
430 joesworkstation
432 corporate.company.com
433 inet:bigcpu
434 local:
435 Users can add or remove hosts from this list and enable or disable
437 access control using the xhost command from the same machine as the
438 server.
439 If the X FireWall Proxy (xfwp) is being used without a sitepolicy,
441 host-based authorization must be turned on for clients to be able to
442 connect to the X server via the xfwp. If xfwp is run without a config‐
443 uration file and thus no sitepolicy is defined, if xfwp is using an X
444 server where xhost + has been run to turn off host-based authorization
445 checks, when a client tries to connect to this X server via xfwp, the X
446 server will deny the connection. See xfwp(1) for more information
447 about this proxy.
448 The X protocol intrinsically does not have any notion of window opera‐
450 tion permissions or place any restrictions on what a client can do; if
451 a program can connect to a display, it has full run of the screen. X
452 servers that support the SECURITY extension fare better because clients
453 can be designated untrusted via the authorization they use to connect;
454 see the xauth(1) manual page for details. Restrictions are imposed on
455 untrusted clients that curtail the mischief they can do. See the SECU‐
456 RITY extension specification for a complete list of these restrictions.
457 Sites that have better authentication and authorization systems might
459 wish to make use of the hooks in the libraries and the server to pro‐
460 vide additional security models.
461
463 The X server attaches special meaning to the following signals:
464 SIGHUP This signal causes the server to close all existing connec‐
466 tions, free all resources, and restore all defaults. It is
467 sent by the display manager whenever the main user's main
468 application (usually an xterm or window manager) exits to force
469 the server to clean up and prepare for the next user.
470 SIGTERM This signal causes the server to exit cleanly.
472 SIGUSR1 This signal is used quite differently from either of the above.
474 When the server starts, it checks to see if it has inherited
475 SIGUSR1 as SIG_IGN instead of the usual SIG_DFL. In this case,
476 the server sends a SIGUSR1 to its parent process after it has
477 set up the various connection schemes. Xdm uses this feature
478 to recognize when connecting to the server is possible.
479
481 The X server can obtain fonts from directories and/or from font
482 servers. The list of directories and font servers the X server uses
483 when trying to open a font is controlled by the font path.
484 The default font path is catalogue:/etc/X11/fontpath.d,built-ins .
486 A special kind of directory can be specified using the catalogue: pre‐
488 fix. Directories specified this way can contain symlinks pointing to
489 the real font directories. See the FONTPATH.D section for details.
490 The font path can be set with the -fp option or by xset(1) after the
492 server has started.
493
495 You can specify a special kind of font path in the form cata‐
496 logue:<dir>. The directory specified after the catalogue: prefix will
497 be scanned for symlinks and each symlink destination will be added as a
498 local fontfile FPE.
499 The symlink can be suffixed by attributes such as 'unscaled', which
501 will be passed through to the underlying fontfile FPE. The only excep‐
502 tion is the newly introduced 'pri' attribute, which will be used for
503 ordering the font paths specified by the symlinks.
504 An example configuration:
506 75dpi:unscaled:pri=20 -> /usr/share/X11/fonts/75dpi
508 ghostscript:pri=60 -> /usr/share/fonts/default/ghostscript
509 misc:unscaled:pri=10 -> /usr/share/X11/fonts/misc
510 type1:pri=40 -> /usr/share/X11/fonts/Type1
511 type1:pri=50 -> /usr/share/fonts/default/Type1
512 This will add /usr/share/X11/fonts/misc as the first FPE with the
514 attribute 'unscaled', second FPE will be /usr/share/X11/fonts/75dpi,
515 also with the attribute 'unscaled' etc. This is functionally equivalent
516 to setting the following font path:
517 /usr/share/X11/fonts/misc:unscaled,
519 /usr/share/X11/fonts/75dpi:unscaled,
520 /usr/share/X11/fonts/Type1,
521 /usr/share/fonts/default/Type1,
522 /usr/share/fonts/default/ghostscript
523
526 /etc/Xn.hosts Initial access control list for display
527 number n
528 /usr/share/fonts/X11/misc,/usr/share/fonts/X11/75dpi,/usr/share/fonts/X11/100dpi
530 Bitmap font directories
531 /usr/share/fonts/X11/TTF,/usr/share/fonts/X11/Type1
533 Outline font directories
534 /tmp/.X11-unix/Xn Unix domain socket for display number n
536 /usr/adm/Xnmsgs Error log file for display number n if
538 run from init(8)
539 /usr/lib/X11/xdm/xdm-errors Default error log file if the server is
541 run from xdm(1)
542
544 General information: X(7)
545 Protocols: X Window System Protocol, The X Font Service Protocol, X
547 Display Manager Control Protocol
548 Fonts: bdftopcf(1), mkfontdir(1), mkfontscale(1), xfs(1), xlsfonts(1),
550 xfontsel(1), xfd(1), X Logical Font Description Conventions
551 Keyboards: xkeyboard-config(7)
553 Security: Xsecurity(7), xauth(1), Xau(1), xdm(1), xhost(1), xfwp(1),
555 Security Extension Specification
556 Starting the server: startx(1), xdm(1), xinit(1)
558 Controlling the server once started: xset(1), xsetroot(1), xhost(1),
560 xinput(1), xrandr(1)
561 Server-specific man pages: Xorg(1), Xdmx(1), Xephyr(1), Xnest(1),
563 Xvfb(1), Xquartz(1), XWin(1).
564 Server internal documentation: Definition of the Porting Layer for the
566 X v11 Sample Server
567
569 The sample server was originally written by Susan Angebranndt, Raymond
570 Drewry, Philip Karlton, and Todd Newman, from Digital Equipment Corpo‐
571 ration, with support from a large cast. It has since been extensively
572 rewritten by Keith Packard and Bob Scheifler, from MIT. Dave Wiggins
573 took over post-R5 and made substantial improvements.
574X Version 11 xorg-server 1.20.3 XSERVER(1)