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 +byteswappedclients
92 Allow connections from clients with an endianess different to
93 that of the server.
94 -byteswappedclients
96 Prohibit connections from clients with an endianess different
97 to that of the server.
98 -c turns off key-click.
100 c volume
102 sets key-click volume (allowable range: 0-100).
103 -cc class
105 sets the visual class for the root window of color screens.
106 The class numbers are as specified in the X protocol. Not
107 obeyed by all servers.
108 -core causes the server to generate a core dump on fatal errors.
110 -displayfd fd
112 specifies a file descriptor in the launching process. Rather
113 than specify a display number, the X server will attempt to
114 listen on successively higher display numbers, and upon finding
115 a free one, will write the display number back on this file de‐
116 scriptor as a newline-terminated string. The -pn option is ig‐
117 nored when using -displayfd.
118 -deferglyphs whichfonts
120 specifies the types of fonts for which the server should at‐
121 tempt to use deferred glyph loading. whichfonts can be all
122 (all fonts), none (no fonts), or 16 (16 bit fonts only).
123 -dpi resolution
125 sets the resolution for all screens, in dots per inch. To be
126 used when the server cannot determine the screen size(s) from
127 the hardware.
128 dpms enables DPMS (display power management services), where sup‐
130 ported. The default state is platform and configuration spe‐
131 cific.
132 -dpms disables DPMS (display power management services). The default
134 state is platform and configuration specific.
135 -extensionextensionName
137 disables named extension. If an unknown extension name is
138 specified, a list of accepted extension names is printed.
139 +extensionextensionName
141 enables named extension. If an unknown extension name is
142 specified, a list of accepted extension names is printed.
143 -f volume
145 sets beep (bell) volume (allowable range: 0-100).
146 -fc cursorFont
148 sets default cursor font.
149 -fn font
151 sets the default font.
152 -fakescreenfps ps
154 sets fake presenter screen default fps (allowable range:
155 1-600).
156 -fp fontPath
158 sets the search path for fonts. This path is a comma separated
159 list of directories which the X server searches for font data‐
160 bases. See the FONTS section of this manual page for more in‐
161 formation and the default list.
162 -help prints a usage message.
164 -I causes all remaining command line arguments to be ignored.
166 -iglx Prohibit creating indirect GLX contexts. Indirect GLX is of
168 limited use, since it lacks support for many modern OpenGL fea‐
169 tures and extensions; it's slower than direct contexts; and it
170 opens a large attack surface for protocol parsing errors. This
171 is the default unless +iglx is specified.
172 +iglx Allow creating indirect GLX contexts.
174 -maxbigreqsize size
176 sets the maximum big request to size MB.
177 -nocursor
179 disable the display of the pointer cursor.
180 -nolisten trans-type
182 disables a transport type. For example, TCP/IP connections can
183 be disabled with -nolisten tcp. This option may be issued mul‐
184 tiple times to disable listening to different transport types.
185 Supported transport types are platform dependent, but commonly
186 include:
187 tcp TCP over IPv4 or IPv6
189 inet TCP over IPv4 only
190 inet6 TCP over IPv6 only
191 unix UNIX Domain Sockets
192 local Platform preferred local connection method
193 -listen trans-type
195 enables a transport type. For example, TCP/IP connections can
196 be enabled with -listen tcp. This option may be issued multi‐
197 ple times to enable listening to different transport types.
198 -noreset
200 prevents a server reset when the last client connection is
201 closed. This overrides a previous -terminate command line op‐
202 tion.
203 -p minutes
205 sets screen-saver pattern cycle time in minutes.
206 -pn permits the server to continue running if it fails to establish
208 all of its well-known sockets (connection points for clients),
209 but establishes at least one. This option is set by default.
210 -nopn causes the server to exit if it fails to establish all of its
212 well-known sockets (connection points for clients).
213 -r turns off auto-repeat.
215 r turns on auto-repeat.
217 -retro starts the server with the classic stipple and cursor visible.
219 The default is to start with a black root window, and to sup‐
220 press display of the cursor until the first time an application
221 calls XDefineCursor(). For kdrive servers, this implies -zap.
222 -s minutes
224 sets screen-saver timeout time in minutes.
225 -su disables save under support on all screens.
227 -seat seat
229 seat to run on. Takes a string identifying a seat in a platform
230 specific syntax. On platforms which support this feature this
231 may be used to limit the server to expose only a specific sub‐
232 set of devices connected to the system.
233 -t number
235 sets pointer acceleration threshold in pixels (i.e. after how
236 many pixels pointer acceleration should take effect).
237 -terminate
239 causes the server to terminate at server reset, instead of con‐
240 tinuing to run. This overrides a previous -noreset command
241 line option.
242 -to seconds
244 sets default connection timeout in seconds.
245 -tst disables all testing extensions (e.g., XTEST, XTrap, XTestEx‐
247 tension1, RECORD).
248 ttyxx ignored, for servers started the ancient way (from init).
250 v sets video-off screen-saver preference.
252 -v sets video-on screen-saver preference.
254 -wm forces the default backing-store of all windows to be When‐
256 Mapped. This is a backdoor way of getting backing-store to ap‐
257 ply to all windows. Although all mapped windows will have
258 backing store, the backing store attribute value reported by
259 the server for a window will be the last value established by a
260 client. If it has never been set by a client, the server will
261 report the default value, NotUseful. This behavior is required
262 by the X protocol, which allows the server to exceed the
263 client's backing store expectations but does not provide a way
264 to tell the client that it is doing so.
265 -wr sets the default root window to solid white instead of the
267 standard root weave pattern.
268 -x extension
270 loads the specified extension at init. This is a no-op for
271 most implementations.
272 [+-]xinerama
274 enables(+) or disables(-) the XINERAMA extension. The default
275 state is platform and configuration specific.
276
278 Some X servers accept the following options:
279 -ld kilobytes
281 sets the data space limit of the server to the specified number
282 of kilobytes. A value of zero makes the data size as large as
283 possible. The default value of -1 leaves the data space limit
284 unchanged.
285 -lf files
287 sets the number-of-open-files limit of the server to the speci‐
288 fied number. A value of zero makes the limit as large as pos‐
289 sible. The default value of -1 leaves the limit unchanged.
290 -ls kilobytes
292 sets the stack space limit of the server to the specified num‐
293 ber of kilobytes. A value of zero makes the stack size as
294 large as possible. The default value of -1 leaves the stack
295 space limit unchanged.
296 -maxclients
298 64|128|256|512 Set the maximum number of clients allowed to
299 connect to the X server. Acceptable values are 64, 128, 256 or
300 512.
301 -render default|mono|gray|color sets the color allocation policy that
303 will be used by the render extension.
304 default selects the default policy defined for the display
306 depth of the X server.
307 mono don't use any color cell.
309 gray use a gray map of 13 color cells for the X render ex‐
311 tension.
312 color use a color cube of at most 4*4*4 colors (that is 64
314 color cells).
315 -dumbSched
317 disables smart scheduling on platforms that support the smart
318 scheduler.
319 -schedInterval interval
321 sets the smart scheduler's scheduling interval to interval mil‐
322 liseconds.
323
325 X servers that support XDMCP have the following options. See the X
326 Display Manager Control Protocol specification for more information.
327 -query hostname
329 enables XDMCP and sends Query packets to the specified host‐
330 name.
331 -broadcast
333 enable XDMCP and broadcasts BroadcastQuery packets to the net‐
334 work. The first responding display manager will be chosen for
335 the session.
336 -multicast [address [hop count]]
338 Enable XDMCP and multicast BroadcastQuery packets to the net‐
339 work. The first responding display manager is chosen for the
340 session. If an address is specified, the multicast is sent to
341 that address. If no address is specified, the multicast is
342 sent to the default XDMCP IPv6 multicast group. If a hop count
343 is specified, it is used as the maximum hop count for the mul‐
344 ticast. If no hop count is specified, the multicast is set to
345 a maximum of 1 hop, to prevent the multicast from being routed
346 beyond the local network.
347 -indirect hostname
349 enables XDMCP and send IndirectQuery packets to the specified
350 hostname.
351 -port port-number
353 uses the specified port-number for XDMCP packets, instead of
354 the default. This option must be specified before any -query,
355 -broadcast, -multicast, or -indirect options.
356 -from local-address
358 specifies the local address to connect from (useful if the con‐
359 necting host has multiple network interfaces). The local-ad‐
360 dress may be expressed in any form acceptable to the host plat‐
361 form's gethostbyname(3) implementation.
362 -once causes the server to terminate (rather than reset) when the
364 XDMCP session ends.
365 -class display-class
367 XDMCP has an additional display qualifier used in resource
368 lookup for display-specific options. This option sets that
369 value, by default it is "MIT-unspecified" (not a very useful
370 value).
371 -cookie xdm-auth-bits
373 When testing XDM-AUTHENTICATION-1, a private key is shared be‐
374 tween the server and the manager. This option sets the value
375 of that private data (not that it is very private, being on the
376 command line!).
377 -displayID display-id
379 Yet another XDMCP specific value, this one allows the display
380 manager to identify each display so that it can locate the
381 shared key.
382
384 X servers that support the XKEYBOARD (a.k.a. "XKB") extension accept
385 the following options. All layout files specified on the command line
386 must be located in the XKB base directory or a subdirectory, and speci‐
387 fied as the relative path from the XKB base directory. The default XKB
388 base directory is /usr/lib/X11/xkb.
389 [+-]accessx [ timeout [ timeout_mask [ feedback [ options_mask ] ] ] ]
391 enables(+) or disables(-) AccessX key sequences.
392 -xkbdir directory
394 base directory for keyboard layout files. This option is not
395 available for setuid X servers (i.e., when the X server's real
396 and effective uids are different).
397 -ardelay milliseconds
399 sets the autorepeat delay (length of time in milliseconds that
400 a key must be depressed before autorepeat starts).
401 -arinterval milliseconds
403 sets the autorepeat interval (length of time in milliseconds
404 that should elapse between autorepeat-generated keystrokes).
405 -xkbmap filename
407 loads keyboard description in filename on server startup.
408
410 The X server supports client connections via a platform-dependent sub‐
411 set of the following transport types: TCP/IP, Unix Domain sockets, and
412 several varieties of SVR4 local connections. See the DISPLAY NAMES
413 section of the X(7) manual page to learn how to specify which transport
414 type clients should try to use.
415
417 The X server implements a platform-dependent subset of the following
418 authorization protocols: MIT-MAGIC-COOKIE-1, XDM-AUTHORIZATION-1, XDM-
419 AUTHORIZATION-2, SUN-DES-1, and MIT-KERBEROS-5. See the Xsecurity(7)
420 manual page for information on the operation of these protocols.
421 Authorization data required by the above protocols is passed to the
423 server in a private file named with the -auth command line option.
424 Each time the server is about to accept the first connection after a
425 reset (or when the server is starting), it reads this file. If this
426 file contains any authorization records, the local host is not automat‐
427 ically allowed access to the server, and only clients which send one of
428 the authorization records contained in the file in the connection setup
429 information will be allowed access. See the Xau manual page for a de‐
430 scription of the binary format of this file. See xauth(1) for mainte‐
431 nance of this file, and distribution of its contents to remote hosts.
432 The X server also uses a host-based access control list for deciding
434 whether or not to accept connections from clients on a particular ma‐
435 chine. If no other authorization mechanism is being used, this list
436 initially consists of the host on which the server is running as well
437 as any machines listed in the file /etc/Xn.hosts, where n is the dis‐
438 play number of the server. Each line of the file should contain either
439 an Internet hostname (e.g. expo.lcs.mit.edu) or a complete name in the
440 format family:name as described in the xhost(1) manual page. There
441 should be no leading or trailing spaces on any lines. For example:
442 joesworkstation
444 corporate.company.com
445 inet:bigcpu
446 local:
447 Users can add or remove hosts from this list and enable or disable ac‐
449 cess control using the xhost command from the same machine as the
450 server.
451 If the X FireWall Proxy (xfwp) is being used without a sitepolicy,
453 host-based authorization must be turned on for clients to be able to
454 connect to the X server via the xfwp. If xfwp is run without a config‐
455 uration file and thus no sitepolicy is defined, if xfwp is using an X
456 server where xhost + has been run to turn off host-based authorization
457 checks, when a client tries to connect to this X server via xfwp, the X
458 server will deny the connection. See xfwp(1) for more information
459 about this proxy.
460 The X protocol intrinsically does not have any notion of window opera‐
462 tion permissions or place any restrictions on what a client can do; if
463 a program can connect to a display, it has full run of the screen. X
464 servers that support the SECURITY extension fare better because clients
465 can be designated untrusted via the authorization they use to connect;
466 see the xauth(1) manual page for details. Restrictions are imposed on
467 untrusted clients that curtail the mischief they can do. See the SECU‐
468 RITY extension specification for a complete list of these restrictions.
469 Sites that have better authentication and authorization systems might
471 wish to make use of the hooks in the libraries and the server to pro‐
472 vide additional security models.
473
475 The X server attaches special meaning to the following signals:
476 SIGHUP This signal causes the server to close all existing connec‐
478 tions, free all resources, and restore all defaults. It is
479 sent by the display manager whenever the main user's main ap‐
480 plication (usually an xterm or window manager) exits to force
481 the server to clean up and prepare for the next user.
482 SIGTERM This signal causes the server to exit cleanly.
484 SIGUSR1 This signal is used quite differently from either of the above.
486 When the server starts, it checks to see if it has inherited
487 SIGUSR1 as SIG_IGN instead of the usual SIG_DFL. In this case,
488 the server sends a SIGUSR1 to its parent process after it has
489 set up the various connection schemes. Xdm uses this feature
490 to recognize when connecting to the server is possible.
491
493 The X server can obtain fonts from directories and/or from font
494 servers. The list of directories and font servers the X server uses
495 when trying to open a font is controlled by the font path.
496 The default font path is catalogue:/etc/X11/fontpath.d,built-ins .
498 A special kind of directory can be specified using the catalogue: pre‐
500 fix. Directories specified this way can contain symlinks pointing to
501 the real font directories. See the FONTPATH.D section for details.
502 The font path can be set with the -fp option or by xset(1) after the
504 server has started.
505
507 You can specify a special kind of font path in the form cata‐
508 logue:<dir>. The directory specified after the catalogue: prefix will
509 be scanned for symlinks and each symlink destination will be added as a
510 local fontfile FPE.
511 The symlink can be suffixed by attributes such as 'unscaled', which
513 will be passed through to the underlying fontfile FPE. The only excep‐
514 tion is the newly introduced 'pri' attribute, which will be used for
515 ordering the font paths specified by the symlinks.
516 An example configuration:
518 75dpi:unscaled:pri=20 -> /usr/share/X11/fonts/75dpi
520 ghostscript:pri=60 -> /usr/share/fonts/default/ghostscript
521 misc:unscaled:pri=10 -> /usr/share/X11/fonts/misc
522 type1:pri=40 -> /usr/share/X11/fonts/Type1
523 type1:pri=50 -> /usr/share/fonts/default/Type1
524 This will add /usr/share/X11/fonts/misc as the first FPE with the at‐
526 tribute 'unscaled', second FPE will be /usr/share/X11/fonts/75dpi, also
527 with the attribute 'unscaled' etc. This is functionally equivalent to
528 setting the following font path:
529 /usr/share/X11/fonts/misc:unscaled,
531 /usr/share/X11/fonts/75dpi:unscaled,
532 /usr/share/X11/fonts/Type1,
533 /usr/share/fonts/default/Type1,
534 /usr/share/fonts/default/ghostscript
535
538 /etc/Xn.hosts Initial access control list for display
539 number n
540 /usr/share/fonts/X11/misc,/usr/share/fonts/X11/75dpi,/usr/share/fonts/X11/100dpi
542 Bitmap font directories
543 /usr/share/fonts/X11/TTF,/usr/share/fonts/X11/Type1
545 Outline font directories
546 /tmp/.X11-unix/Xn Unix domain socket for display number n
548 /usr/adm/Xnmsgs Error log file for display number n if
550 run from init(8)
551 /usr/lib/X11/xdm/xdm-errors Default error log file if the server is
553 run from xdm(1)
554
556 General information: X(7)
557 Protocols: X Window System Protocol, The X Font Service Protocol, X
559 Display Manager Control Protocol
560 Fonts: bdftopcf(1), mkfontdir(1), mkfontscale(1), xfs(1), xlsfonts(1),
562 xfontsel(1), xfd(1), X Logical Font Description Conventions
563 Keyboards: xkeyboard-config(7)
565 Security: Xsecurity(7), xauth(1), Xau(1), xdm(1), xhost(1), xfwp(1),
567 Security Extension Specification
568 Starting the server: startx(1), xdm(1), xinit(1)
570 Controlling the server once started: xset(1), xsetroot(1), xhost(1),
572 xinput(1), xrandr(1)
573 Server-specific man pages: Xorg(1), Xdmx(1), Xephyr(1), Xnest(1),
575 Xvfb(1), Xquartz(1), XWin(1).
576 Server internal documentation: Definition of the Porting Layer for the
578 X v11 Sample Server
579
581 The sample server was originally written by Susan Angebranndt, Raymond
582 Drewry, Philip Karlton, and Todd Newman, from Digital Equipment Corpo‐
583 ration, with support from a large cast. It has since been extensively
584 rewritten by Keith Packard and Bob Scheifler, from MIT. Dave Wiggins
585 took over post-R5 and made substantial improvements.
586X Version 11 xorg-server 1.20.14 XSERVER(1)