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NAME

       X0tigervnc - TigerVNC Server for X displays

SYNOPSIS

       X0tigervnc [options]
       X0tigervnc -version

DESCRIPTION

       X0tigervnc  is  a  TigerVNC  Server which makes any X display remotely accessible via VNC,
       TigerVNC or compatible viewers.   Unlike  Xtigervnc(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 X0tigervnc will  fall
       back to polling the screen for changes.

OPTIONS

       X0tigervnc  interprets  the  command  line  as  a list of parameters with optional values.
       Running X0tigervnc -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 description below).

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

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

       -SomeParameter=0
              Disable the parameter, turn the feature off.

       -SomeParameter=value
              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.

PARAMETERS

       -desktop desktop-name
              Each  desktop  has  a  name  which  may  be displayed by the viewer. It defaults to
              "<user>@<hostname>".

       -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 X0tigervnc listens for connections from viewers
              (the protocol used in VNC is called RFB - "remote framebuffer").  The default  port
              is 5900. Specify -1 to disable listening on a TCP port.

       -UseIPv4
              Use IPv4 for incoming and outgoing connections. Default is on.

       -UseIPv6
              Use IPv6 for incoming and outgoing connections. Default is on.

       -rfbunixpath path
              Specifies  the  path  of  a  Unix  domain  socket  on  which X0tigervnc listens for
              connections from viewers.

       -rfbunixmode mode
              Specifies the mode of the Unix domain socket.  The default is 0600.

       -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 one to specify a file name with IP access control 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 specified as a number of bits (e.g. /24).  Default is to
              accept connections 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. Default 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
              tigervncpasswd(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 authenticate  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 session’s handshake algorithms.  See
              the GnuTLS manual for possible values. Default is NORMAL.

       -UseBlacklist
              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 expires.  Default is 10.

       -QueryConnect
              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.

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

       -interface IP address
              Listen on interface. By default X0tigervnc listens on all available interfaces.

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

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

       -DisconnectClients
              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.

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

       -AcceptPointerEvents
              Accept pointer press and release events from clients. Default is on.

       -AcceptSetDesktopSize
              Accept requests to resize the size of the desktop. Default is on.

       -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:

                 RemapKeys=0x22<>0x40

       -RawKeyboard
              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.

       -Protocol3.3
              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  optional,  +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 dynamically adjusted to
              satisfy MaxProcessorUsage setting.  Default 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 aggregated 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.

       -UseSHM
              Use MIT-SHM extension if available.  Using that extension accelerates  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.  Default is to use the standard  compression
              level provided by the zlib(3) compression library.

       -ImprovedHextile
              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.  Default is 0.

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

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

SEE ALSO

       Xtigervnc(1), tigervncpasswd(1),
       https://www.tigervnc.org/

AUTHOR

       Constantin Kaplinsky and others.

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