1XSERVER(1)                  General Commands Manual                 XSERVER(1)
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NAME

6       Xserver - X Window System display server
7

SYNOPSIS

9       X [option ...]
10

DESCRIPTION

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

STARTING THE SERVER

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
23       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
29       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
35       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

OPTIONS

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
44       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
49       :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
56       -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
60       -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
65       -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
74       -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
79       -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
85       -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
89       -bs     disables backing store support on all screens.
90
91       -c      turns off key-click.
92
93       c volume
94               sets key-click volume (allowable range: 0-100).
95
96       -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
101       -core   causes the server to generate a core dump on fatal errors.
102
103       -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
111       -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
116       -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
121       dpms    enables DPMS (display power management  services),  where  sup‐
122               ported.   The  default state is platform and configuration spe‐
123               cific.
124
125       -dpms   disables DPMS (display power management services).  The default
126               state is platform and configuration specific.
127
128       -extensionextensionName
129               disables  named  extension.    If  an unknown extension name is
130               specified, a list of accepted extension names is printed.
131
132       +extensionextensionName
133               enables named extension.   If  an  unknown  extension  name  is
134               specified, a list of accepted extension names is printed.
135
136       -f volume
137               sets beep (bell) volume (allowable range: 0-100).
138
139       -fc cursorFont
140               sets default cursor font.
141
142       -fn font
143               sets the default font.
144
145       -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
151       -help   prints a usage message.
152
153       -I      causes all remaining command line arguments to be ignored.
154
155       -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
161       +iglx   Allow creating indirect GLX contexts.
162
163       -maxbigreqsize size
164               sets the maximum big request to size MB.
165
166       -nocursor
167               disable the display of the pointer cursor.
168
169       -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
176               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
182       -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
187       -noreset
188               prevents a server reset when  the  last  client  connection  is
189               closed.   This  overrides  a  previous  -terminate command line
190               option.
191
192       -p minutes
193               sets screen-saver pattern cycle time in minutes.
194
195       -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
199       -nopn   causes the server to exit if it fails to establish all  of  its
200               well-known sockets (connection points for clients).
201
202       -r      turns off auto-repeat.
203
204       r       turns on auto-repeat.
205
206       -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
211       -s minutes
212               sets screen-saver timeout time in minutes.
213
214       -su     disables save under support on all screens.
215
216       -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
222       -t number
223               sets  pointer  acceleration threshold in pixels (i.e. after how
224               many pixels pointer acceleration should take effect).
225
226       -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
231       -to seconds
232               sets default connection timeout in seconds.
233
234       -tst    disables all testing extensions (e.g., XTEST,  XTrap,  XTestEx‐
235               tension1, RECORD).
236
237       ttyxx   ignored, for servers started the ancient way (from init).
238
239       v       sets video-off screen-saver preference.
240
241       -v      sets video-on screen-saver preference.
242
243       -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
254       -wr     sets the default root window to  solid  white  instead  of  the
255               standard root weave pattern.
256
257       -x extension
258               loads  the  specified  extension  at init.  This is a no-op for
259               most implementations.
260
261       [+-]xinerama
262               enables(+) or disables(-) the XINERAMA extension.  The  default
263               state is platform and configuration specific.
264

SERVER DEPENDENT OPTIONS

266       Some X servers accept the following options:
267
268       -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
274       -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
279       -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
285       -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
290       -render default|mono|gray|color  sets  the color allocation policy that
291               will be used by the render extension.
292
293               default selects the default  policy  defined  for  the  display
294                       depth of the X server.
295
296               mono    don't use any color cell.
297
298               gray    use  a  gray  map  of  13  color cells for the X render
299                       extension.
300
301               color   use a color cube of at most 4*4*4 colors  (that  is  64
302                       color cells).
303
304       -dumbSched
305               disables  smart  scheduling on platforms that support the smart
306               scheduler.
307
308       -schedInterval interval
309               sets the smart scheduler's scheduling interval to interval mil‐
310               liseconds.
311

XDMCP OPTIONS

313       X  servers  that  support  XDMCP have the following options.  See the X
314       Display Manager Control Protocol specification for more information.
315
316       -query hostname
317               enables XDMCP and sends Query packets to  the  specified  host‐
318               name.
319
320       -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
325       -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
336       -indirect hostname
337               enables  XDMCP  and send IndirectQuery packets to the specified
338               hostname.
339
340       -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
345       -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
351       -once   causes  the  server  to  terminate (rather than reset) when the
352               XDMCP session ends.
353
354       -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
360       -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
366       -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

XKEYBOARD OPTIONS

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
378       [+-]accessx [ timeout [ timeout_mask [ feedback [ options_mask ] ] ] ]
379               enables(+) or disables(-) AccessX key sequences.
380
381       -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
386       -ardelay milliseconds
387               sets the autorepeat delay (length of time in milliseconds  that
388               a key must be depressed before autorepeat starts).
389
390       -arinterval milliseconds
391               sets  the  autorepeat  interval (length of time in milliseconds
392               that should elapse between autorepeat-generated keystrokes).
393
394       -xkbmap filename
395               loads keyboard description in filename on server startup.
396

NETWORK CONNECTIONS

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

GRANTING ACCESS

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
410       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
421       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
431               joesworkstation
432               corporate.company.com
433               inet:bigcpu
434               local:
435
436       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
440       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
449       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
458       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

SIGNALS

463       The X server attaches special meaning to the following signals:
464
465       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
471       SIGTERM This signal causes the server to exit cleanly.
472
473       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

FONTS

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
485       The default font path is catalogue:/etc/X11/fontpath.d,built-ins .
486
487       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
491       The  font  path  can be set with the -fp option or by xset(1) after the
492       server has started.
493

FONTPATH.D

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
500       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
505       An example configuration:
506
507           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
513       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
518           /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
524

FILES

526       /etc/Xn.hosts                 Initial  access  control list for display
527                                     number n
528
529       /usr/share/fonts/X11/misc,/usr/share/fonts/X11/75dpi,/usr/share/fonts/X11/100dpi
530                                     Bitmap font directories
531
532       /usr/share/fonts/X11/TTF,/usr/share/fonts/X11/Type1
533                                     Outline font directories
534
535       /tmp/.X11-unix/Xn             Unix domain socket for display number n
536
537       /usr/adm/Xnmsgs               Error  log  file  for display number n if
538                                     run from init(8)
539
540       /usr/lib/X11/xdm/xdm-errors   Default error log file if the  server  is
541                                     run from xdm(1)
542

SEE ALSO

544       General information: X(7)
545
546       Protocols:  X  Window  System  Protocol, The X Font Service Protocol, X
547       Display Manager Control Protocol
548
549       Fonts: bdftopcf(1), mkfontdir(1), mkfontscale(1), xfs(1),  xlsfonts(1),
550       xfontsel(1), xfd(1), X Logical Font Description Conventions
551
552       Keyboards: xkeyboard-config(7)
553
554       Security:  Xsecurity(7),  xauth(1),  Xau(1), xdm(1), xhost(1), xfwp(1),
555       Security Extension Specification
556
557       Starting the server: startx(1), xdm(1), xinit(1)
558
559       Controlling the server once started:  xset(1),  xsetroot(1),  xhost(1),
560       xinput(1), xrandr(1)
561
562       Server-specific  man  pages:  Xorg(1),  Xdmx(1),  Xephyr(1),  Xnest(1),
563       Xvfb(1), Xquartz(1), XWin(1).
564
565       Server internal documentation: Definition of the Porting Layer for  the
566       X v11 Sample Server
567

AUTHORS

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.
574
575
576
577X Version 11                  xorg-server 1.20.8                    XSERVER(1)
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