Ubuntu Manpage: X0tigervnc - TigerVNC Server for X displays

Provided by: tigervnc-scraping-server_1.12.0+dfsg-4ubuntu0.22.04.1_amd64

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.

AUTHOR