X0VNCSERVER(1) TigerVNC Manual X0VNCSERVER(1)
x0vncserver - TigerVNC Server for X displays
x0vncserver is a TigerVNC Server which makes any X display remotely accessible 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 physi-
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 description below).
There are several forms of specifying parameters in the command line (here we use `SomePa-
rameter' 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.
The X display name. If not specified, it defaults to the value of the DISPLAY
TCP port to listen for incoming VNC connections (RFB protocol). The default port
Log Specifies which log output should be directed to which target logger, and the level
of output to log. Format is log:target:level. Default is *:stderr:30 (log every-
thing to stderr, set log level to 30). Log level should be a value between 0 and
100, higher levels produce more output.
This parameter allows 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/netmask (accept connections from the specified address group),
-address/netmask (reject connections) or ?address/netmask (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. Net-
mask is optional and can be specified either in dotted format (e.g.
/255.255.255.0), or as a single number of bits (e.g. /24). Default is to accept
connections from any IP address.
Specify which security scheme to use for incoming connections. Valid values are
None and VncAuth. Default is VncAuth.
Service name for pam password validation (default is "vnc").
Users permission to access via Plain security type.
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)
Obfuscated binary encoding of the password which clients must supply to access the
server. Using this parameter is insecure, use PasswordFile parameter instead.
The number of unauthenticated connection attempts allowed from any individual host
before that host is black-listed. Default is 5.
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.
Prompt the local user to accept or reject incoming connections. Default is off.
Number of seconds to show the Accept Connection dialog before rejecting the connec-
tion. Default is 10.
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 set-
ting. Default is off.
Disconnect existing clients if an incoming connection is non-shared. If combined
with NeverShared then new connections will be refused while there is a client
active. Default is on.
Accept key press and release events from clients. Default is on.
Accept pointer events from clients. Default is on.
Accept clipboard updates from clients. Default is on.
Maximum permitted length of an incoming clipboard update (default is 262144).
Send clipboard changes to clients. Default is on.
Comma-separated list of incoming keysyms to remap. Mappings are expressed as two
hex values, prefixed by 0x, and separated by -> (`dash' and `greater than' charac-
Always use RFB protocol version 3.3 for backwards compatibility with badly-behaved
clients. Default is off.
This option specifies the screen area that will be shown to VNC clients. The for-
mat 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. Off-
sets 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).
Maximum percentage of CPU time to be consumed when polling the screen. Default is
Milliseconds per one polling cycle. Actual interval may be dynamically adjusted to
satisfy MaxProcessorUsage setting. Default is 30.
This option specifies the screen area that will be handled as video. 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). Video area is not checked
for actual changes, it is assumed to be changing continuously and is sent in each
screen update. Normally, video area is compressed with JPEG (if allowed by the
client). Note that this setting can be overriden by TigerVNC clients supporting
VideoRectangleSelection protocol extension. In other words, clients may choose
video selection themselves, but if they do not, then the VideoArea parameter will
take effect. If the argument is empty, no video area is set (this is the default).
Perform pixel comparison on framebuffer to reduce unnecessary updates. Default is
UseSHM Use MIT-SHM extension if available. Using that extension accelerates reading the
screen. Default is on.
Use overlay mode in IRIX or Solaris (does not have effect in other systems). This
enables system-specific access to complete full-color version of the screen (the
default X visual often provides 256 colors). Also, in overlay mode, x0vncserver
can show correct mouse cursor. Default is on.
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.
Use improved compression algorithm for Hextile encoding which achieves better com-
pression ratios by the cost of using slightly more CPU time. Default is on.
The number of seconds after which an idle VNC connection will be dropped (zero
means no timeout). Default is 0.
Terminate when no client has been connected for N seconds. Default is 0.
Terminate when a client has been connected for N seconds. Default is 0.
Terminate after N seconds of user inactivity. Default is 0.
The number of milliseconds to wait for a client which is no longer responding.
Default is 20000.
Time in milliseconds to defer updates (default is 1).
Always reset the defer update timer on every change.
Path to key of the x509 certificate in PEM format.
Path to x509 certificate in PEM format.
This manual page was written by Constantin Kaplinsky.
TigerVNC Dec 23, 2008 X0VNCSERVER(1)