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       x0vncserver - TigerVNC Server for X displays

       x0vncserver [options]
       x0vncserver -version

       x0vncserver is a	TigerVNC Server	which makes any	X display remotely ac-
       cessible	via VNC, TigerVNC or compatible	viewers.  Unlike  Xvnc(1),  it
       does not	create a virtual display.  Instead, it just shares an existing
       X server	(typically, that one connected to the physical screen).

       XDamage will be used if the existing X server  supports	it.  Otherwise
       x0vncserver will	fall back to polling the screen	for changes.

       x0vncserver  interprets	the  command line as a list of parameters with
       optional	values.	 Running x0vncserver -h	will show a list of all	 valid
       parameters  with	 short descriptions.  All parameters are optional, but
       normally	you would have to use the PasswordFile parameter (see its  de-
       scription below).

       There  are  several  forms of specifying	parameters in the command line
       (here we	use `SomeParameter' as an example parameter name):

	      Enable the parameter, turn the feature on.   This	 form  can  be
	      used with	parameters that	simply enable or disable some feature.

	      Disable the parameter, turn the feature off.

	      Assign  the  specified value to the parameter.  The leading dash
	      can be omitted, or it can	be doubled if desired  (like  in  GNU-
	      style long options).

       Parameter  names	 are case-insensitive, their order in the command line
       can be arbitrary.

       -display	display
	      The X display name.  If not specified, it	defaults to the	 value
	      of the DISPLAY environment variable.

       -rfbport	port
	      Specifies	 the TCP port on which x0vncserver listens for connec-
	      tions from viewers (the protocol used in VNC  is	called	RFB  -
	      "remote framebuffer").  The default port is 5900.

	      Use IPv4 for incoming and	outgoing connections. Default is on.

	      Use IPv6 for incoming and	outgoing connections. Default is on.

       -rfbunixpath path
	      Specifies	 the path of a Unix domain socket on which x0vncserver
	      listens for connections from viewers, instead of listening on  a
	      TCP port.

       -rfbunixmode mode
	      Specifies	 the  mode  of the Unix	domain socket.	The default is

       -Log logname:dest:level
	      Configures the  debug  log  settings.   dest  can	 currently  be
	      stderr,  stdout  or  syslog, and level is	between	0 and 100, 100
	      meaning most verbose output.  logname is usually * meaning  all,
	      but  you	can target a specific source file if you know the name
	      of its "LogWriter".  Default is *:stderr:30.

       -HostsFile filename
	      This parameter allows to specify a file name with	IP access con-
	      trol  rules.  The	file should include one	rule per line, and the
	      rule format is one of  the  following:  +address/prefix  (accept
	      connections  from	 the specified address group), -address/prefix
	      (reject connections) or ?address/prefix (query the local	user).
	      The  first rule matching the IP address determines the action to
	      be performed.  Rules that	include	only an	action sign (+,	 -  or
	      ?)  will match any IP address.  Prefix is	optional and is	speci-
	      fied as a	number of bits (e.g. /24).  Default is to accept  con-
	      nections from any	IP address.

       -SecurityTypes sec-types
	      Specify  which  security scheme to use for incoming connections.
	      Valid values are a comma separated list of None, VncAuth,	Plain,
	      TLSNone,	TLSVnc,	TLSPlain, X509None, X509Vnc and	X509Plain. De-
	      fault is VncAuth,TLSVnc.

       -rfbauth	passwd-file, -PasswordFile passwd-file
	      Password file for	VNC authentication.  There is no default,  you
	      should  specify  the  password  file  explicitly.	 Password file
	      should be	created	with the vncpasswd(1) utility.	 The  file  is
	      accessed	each  time a connection	comes in, so it	can be changed
	      on the fly.

       -Password password
	      Obfuscated binary	encoding of the	password  which	 clients  must
	      supply  to access	the server.  Using this	parameter is insecure,
	      use PasswordFile parameter instead.

       -PlainUsers user-list
	      A	comma separated	list of	user names that	are allowed to authen-
	      ticate  via  any of the "Plain" security types (Plain, TLSPlain,
	      etc.). Specify * to allow	any user to  authenticate  using  this
	      security type. Default is	to deny	all users.

       -pam_service name, -PAMService name
	      PAM  service  name to use	when authentication users using	any of
	      the "Plain" security types. Default is vnc.

       -X509Cert path
	      Path to a	X509 certificate in PEM	format to be used for all X509
	      based security types (X509None, X509Vnc, etc.).

       -X509Key	path
	      Private  key  counter part to the	certificate given in X509Cert.
	      Must also	be in PEM format.

       -GnuTLSPriority priority
	      GnuTLS priority string that controls the TLS sessionas handshake
	      algorithms.   See	the GnuTLS manual for possible values. Default
	      is NORMAL.

	      Temporarily reject connections from  a  host  if	it  repeatedly
	      fails to authenticate. Default is	on.

       -BlacklistThreshold count
	      The  number  of unauthenticated connection attempts allowed from
	      any individual host before that host is  black-listed.   Default
	      is 5.

       -BlacklistTimeout seconds
	      The  initial  timeout applied when a host	is first black-listed.
	      The host cannot re-attempt a connection until  the  timeout  ex-
	      pires.  Default is 10.

	      Prompts  the  user of the	desktop	to explicitly accept or	reject
	      incoming connections. Default is off.

       -QueryConnectTimeout seconds
	      Number of	seconds	to show	the Accept  Connection	dialog	before
	      rejecting	the connection.	 Default is 10.

	      Only  allow connections from the same machine. Useful if you use
	      SSH and want to stop non-SSH connections from any	other hosts.

	      Always treat incoming connections	as shared, regardless  of  the
	      client-specified setting.	Default	is off.

	      Never  treat  incoming  connections as shared, regardless	of the
	      client-specified setting.	Default	is off.

	      Disconnect existing clients if an	incoming  connection  is  non-
	      shared. Default is on. If	DisconnectClients is false, then a new
	      non-shared connection will be refused while there	 is  a	client
	      active.	When  combined	with  NeverShared  this	means only one
	      client is	allowed	at a time.

	      Accept key press and release events from clients.	Default	is on.

	      Accept pointer press and release events from clients. Default is

	      Accept  requests	to  resize the size of the desktop. Default is

       -RemapKeys mapping
	      Sets up a	keyboard mapping.  mapping is a	comma-separated	string
	      of   character   mappings,  each	of  the	 form  char->char,  or
	      char<>char, where	char is	a hexadecimal keysym. For example,  to
	      exchange the " and @ symbols you would specify the following:


	      Send  keyboard events straight through and avoid mapping them to
	      the current keyboard layout. This	effectively makes the keyboard
	      behave  according	to the layout configured on the	server instead
	      of the layout configured on the client. Default is off.

	      Always use protocol version 3.3 for backwards compatibility with
	      badly-behaved clients. Default is	off.

       -Geometry geometry
	      This  option specifies the screen	area that will be shown	to VNC
	      clients.	The format is widthxheight+xoffset+yoffset , where `+'
	      signs can	be replaced with `-' signs to specify offsets from the
	      right and/or from	the bottom of the  screen.   Offsets  are  op-
	      tional,  +0+0  is	 assumed by default (top left corner).	If the
	      argument is empty, full screen is	shown to VNC clients (this  is
	      the default).

       -MaxProcessorUsage percent
	      Maximum  percentage  of CPU time to be consumed when polling the
	      screen.  Default is 35.

       -PollingCycle milliseconds
	      Milliseconds per one polling cycle.  Actual interval may be  dy-
	      namically	 adjusted  to  satisfy MaxProcessorUsage setting.  De-
	      fault is 30.

       -FrameRate fps
	      The maximum number of updates per	second sent to each client. If
	      the  screen updates any faster then those	changes	will be	aggre-
	      gated and	sent in	a single update	to the client. Note that  this
	      only controls the	maximum	rate and a client may get a lower rate
	      when resources are limited. Default is 60.

       -CompareFB mode
	      Perform pixel comparison on framebuffer  to  reduce  unnecessary
	      updates.	Can be either 0	(off), 1 (always) or 2 (auto). Default
	      is 2.

	      Use MIT-SHM extension if available.  Using that extension	accel-
	      erates reading the screen.  Default is on.

       -ZlibLevel level
	      Zlib  compression	 level	for  ZRLE encoding (it does not	affect
	      Tight encoding).	Acceptable values are between 0	 and  9.   De-
	      fault  is	 to use	the standard compression level provided	by the
	      zlib(3) compression library.

	      Use improved compression algorithm for  Hextile  encoding	 which
	      achieves better compression ratios by the	cost of	using slightly
	      more CPU time.  Default is on.

       -IdleTimeout seconds
	      The number of seconds after which	an idle	VNC connection will be
	      dropped.	 Default  is 0,	which means that idle connections will
	      never be dropped.

       -MaxDisconnectionTime seconds
	      Terminate	when no	client has been	connected for N	seconds.   De-
	      fault is 0.

       -MaxConnectionTime seconds
	      Terminate	 when  a client	has been connected for N seconds.  De-
	      fault is 0.

       -MaxIdleTime seconds
	      Terminate	after N	seconds	of user	inactivity.  Default is	0.

       -ClientWaitTimeMillis time
	      Time in milliseconds to wait for a viewer	which is blocking  the
	      server.  This is necessary because the server is single-threaded
	      and sometimes blocks until the viewer has	 finished  sending  or
	      receiving	 a  message  -	note that this does not	mean an	update
	      will be aborted after this time.	Default	is 20000 (20 seconds).

	      Currently	unused.

       Xvnc(1),	vncpasswd(1),

       Constantin Kaplinsky and	others.

       VNC was originally developed by the RealVNC team	while at Olivetti  Re-
       search  Ltd / AT&T Laboratories Cambridge.  TightVNC additions were im-
       plemented by Constantin Kaplinsky. Many other people have since partic-
       ipated  in development, testing and support. This manual	is part	of the
       TigerVNC	software suite.

TigerVNC							X0VNCSERVER(1)


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