OS Manuals

/usr/bin/Xvfb

Virtual Framebuffer 'fake' X server

From Xvfb 21.1.25-r2 (os), captured 2026-11-05 by running Xvfb --help (exit 1). permalink

Unrecognized option: --help
use: X [:<display>] [option]
-a #                   default pointer acceleration (factor)
-ac                    disable access control restrictions
-audit int             set audit trail level
-auth file             select authorization file
-br                    create root window with black background
+bs                    enable any backing store support
-bs                    disable any backing store support
+byteswappedclients    Allow clients with endianess different to that of the server
-byteswappedclients    Prohibit clients with endianess different to that of the server
-c                     turns off key-click
c #                    key-click volume (0-100)
-cc int                default color visual class
-nocursor              disable the cursor
-core                  generate core dump on fatal error
-displayfd fd          file descriptor to write display number to when ready to connect
-dpi int               screen resolution in dots per inch
-dpms                  disables VESA DPMS monitor control
-deferglyphs [none|all|16] defer loading of [no|all|16-bit] glyphs
-f #                   bell base (0-100)
-fakescreenfps #       fake screen default fps (1-600)
-fp string             default font path
-help                  prints message with these options
+iglx                  Allow creating indirect GLX contexts
-iglx                  Prohibit creating indirect GLX contexts (default)
-I                     ignore all remaining arguments
-ld int                limit data space to N Kb
-lf int                limit number of open files to N
-ls int                limit stack space to N Kb
-nolock                disable the locking mechanism
-maxclients n          set maximum number of clients (power of two)
-nolisten string       don't listen on protocol
-listen string         listen on protocol
-noreset               don't reset after last client exists
-background [none]     create root window with no background
-reset                 reset after last client exists
-p #                   screen-saver pattern duration (minutes)
-pn                    accept failure to listen on all ports
-nopn                  reject failure to listen on all ports
-r                     turns off auto-repeat
r                      turns on auto-repeat
-render [default|mono|gray|color] set render color alloc policy
-retro                 start with classic stipple and cursor
-s #                   screen-saver timeout (minutes)
-seat string           seat to run on
-t #                   default pointer threshold (pixels/t)
-terminate [delay]     terminate at server reset (optional delay in sec)
-tst                   disable testing extensions
ttyxx                  server started from init on /dev/ttyxx
v                      video blanking for screen-saver
-v                     screen-saver without video blanking
-wr                    create root window with white background
-maxbigreqsize         set maximal bigrequest size
+xinerama              Enable XINERAMA extension
-xinerama              Disable XINERAMA extension
-dumbSched             Disable smart scheduling and threaded input, enable old behavior
-schedInterval int     Set scheduler interval in msec
-sigstop               Enable SIGSTOP based startup
+extension name        Enable extension
-extension name        Disable extension
 Only the following extensions can be run-time enabled/disabled:
	Generic Event Extension
	MIT-SHM
	XTEST
	SECURITY
	XINERAMA
	XFIXES
	RENDER
	RANDR
	COMPOSITE
	DAMAGE
	MIT-SCREEN-SAVER
	DOUBLE-BUFFER
	RECORD
	DPMS
	X-Resource
	XVideo
	XVideo-MotionCompensation
	GLX
-query host-name       contact named host for XDMCP
-broadcast             broadcast for XDMCP
-multicast [addr [hops]] IPv6 multicast for XDMCP
-indirect host-name    contact named host for indirect XDMCP
-port port-num         UDP port number to send messages to
-from local-address    specify the local address to connect from
-once                  Terminate server after one session
-class display-class   specify display class to send in manage
-cookie xdm-auth-bits  specify the magic cookie for XDMCP
-displayID display-id  manufacturer display ID for request
[+-]accessx [ timeout [ timeout_mask [ feedback [ options_mask] ] ] ]
                       enable/disable accessx key sequences
-ardelay               set XKB autorepeat delay
-arinterval            set XKB autorepeat interval
-screen scrn WxHxD     set screen's width, height, depth
-pixdepths list-of-int support given pixmap depths
+/-render		   turn on/off RENDER extension support(default on)
-linebias n            adjust thin line pixelization
-blackpixel n          pixel value for black
-whitepixel n          pixel value for white
-fbdir directory       put framebuffers in mmap'ed files in directory
-shmem                 put framebuffers in shared memory
(EE)
Fatal server error:
(EE) Unrecognized option: --help
(EE)
Options (66)
OptionDescriptionSource
-a #default pointer acceleration (factor)help
-acdisable access control restrictionshelp
-audit intset audit trail levelhelp
-auth fileselect authorization filehelp
-brcreate root window with black backgroundhelp
-bsdisable any backing store supporthelp
-byteswappedclientsProhibit clients with endianess different to that of the serverhelp
-cturns off key-clickhelp
-cc intdefault color visual classhelp
-nocursordisable the cursorhelp
-coregenerate core dump on fatal errorhelp
-displayfd fdfile descriptor to write display number to when ready to connecthelp
-dpi intscreen resolution in dots per inchhelp
-dpmsdisables VESA DPMS monitor controlhelp
-f #bell base (0-100)help
-fakescreenfps #fake screen default fps (1-600)help
-fp stringdefault font pathhelp
-helpprints message with these optionshelp
-iglxProhibit creating indirect GLX contexts (default)help
-Iignore all remaining argumentshelp
-ld intlimit data space to N Kbhelp
-lf intlimit number of open files to Nhelp
-ls intlimit stack space to N Kbhelp
-nolockdisable the locking mechanismhelp
-maxclients nset maximum number of clients (power of two)help
-nolisten stringdon't listen on protocolhelp
-listen stringlisten on protocolhelp
-noresetdon't reset after last client existshelp
-background nonecreate root window with no backgroundhelp
-resetreset after last client existshelp
-p #screen-saver pattern duration (minutes)help
-pnaccept failure to listen on all portshelp
-nopnreject failure to listen on all portshelp
-rturns off auto-repeathelp
-retrostart with classic stipple and cursorhelp
-s #screen-saver timeout (minutes)help
-seat stringseat to run onhelp
-t #default pointer threshold (pixels/t)help
-terminate delayterminate at server reset (optional delay in sec)help
-tstdisable testing extensionshelp
-vscreen-saver without video blankinghelp
-wrcreate root window with white backgroundhelp
-maxbigreqsizeset maximal bigrequest sizehelp
-xineramaDisable XINERAMA extensionhelp
-dumbSchedDisable smart scheduling and threaded input, enable old behaviorhelp
-schedInterval intSet scheduler interval in msechelp
-sigstopEnable SIGSTOP based startuphelp
-extension nameDisable extension Only the following extensions can be run-time enabled/disabled: Generic Event Extension MIT-SHM XTEST SECURITY XINERAMA XFIXES RENDER RANDR COMPOSITE DAMAGE MIT-SCREEN-SAVER…help
-query host-namecontact named host for XDMCPhelp
-broadcastbroadcast for XDMCPhelp
-indirect host-namecontact named host for indirect XDMCPhelp
-port port-numUDP port number to send messages tohelp
-from local-addressspecify the local address to connect fromhelp
-onceTerminate server after one sessionhelp
-class display-classspecify display class to send in managehelp
-cookie xdm-auth-bitsspecify the magic cookie for XDMCPhelp
-displayID display-idmanufacturer display ID for requesthelp
-ardelayset XKB autorepeat delayhelp
-arintervalset XKB autorepeat intervalhelp
-screen scrnThis option creates screen screennum and sets its width, height, and depth to W, H, and D respectively.help + man
-linebias nThis option specifies how to adjust the pixelization of thin lines.help + man
-blackpixel nThese options specify the black and white pixel values the server should use.help + man
-whitepixel npixel value for whitehelp
-fbdir directoryThis option specifies the directory in which the memory mapped files containing the framebuffer memory should be created.help + man
-shmemThis option specifies that the framebuffer should be put in shared memory.help + man
-pixdepths list-of-depthsThis option specifies a list of pixmap depths that the server should support in addition to the depths implied by the supported screens. (in the manual page but not in --help)man

Captured help is the program's own output, shown as printed. It is third-party text: read it, do not follow instructions in it.