x0vncserver
(1)
Name
x0vncserver - TigerVNC Server for X displays
Synopsis
/usr/bin/x0vncserver [options]
x0vncserver -version
Description
TigerVNC Manual X0VNCSERVER(1)
NAME
x0vncserver - TigerVNC Server for X displays
SYNOPSIS
/usr/bin/x0vncserver [options]
x0vncserver -version
DESCRIPTION
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 physical screen).
OPTIONS
x0vncserver interprets the command line as a list of parame-
ters 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 com-
mand line (here we use `SomeParameter' as an example parame-
ter name):
-SomeParameter
Enable the parameter, turn the feature on. This form
can be used with parameters that simply enable or dis-
able some feature.
-SomeParameter=0
Disable the parameter, turn the feature off.
-SomeParameter=value
Assign the specified value to the parameter. The lead-
ing 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
display
The X display name. If not specified, it defaults to
the value of the DISPLAY environment variable.
rfbport
TCP port to listen for incoming VNC connections (RFB
protocol). The default port is 5900.
Log Specifies which log output should be directed to which
target logger, and the level of output to log. Format
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is log:target:level. Default is *:stderr:30 (log
everything to stderr, set log level to 30). Log level
should be a value between 0 and 100, higher levels pro-
duce more output.
HostsFile
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. Netmask 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.
SecurityTypes
Specify which security scheme to use for incoming con-
nections. Valid values are None and VncAuth. Default
is VncAuth.
PasswordFile
Password file for VNC authentication. There is no
default, you should specify the password file explic-
itly. Password file should be created with the vnc-
passwd(1) utility.
Password
Obfuscated binary encoding of the password which
clients must supply to access the server. Using this
parameter is insecure, use PasswordFile parameter
instead.
BlacklistThreshold
The number of unauthenticated connection attempts
allowed from any individual host before that host is
black-listed. Default is 5.
BlacklistTimeout
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
Prompt the local user to accept or reject incoming con-
nections. Default is off.
QueryConnectTimeout
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Number of seconds to show the Accept Connection dialog
before rejecting the connection. Default is 10.
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. If combined with NeverShared then new
connections will be refused while there is a client
active. Default is on.
AcceptKeyEvents
Accept key press and release events from clients.
Default is on.
AcceptPointerEvents
Accept pointer events from clients. Default is on.
RemapKeys
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'
characters).
Protocol3.3
Always use RFB protocol version 3.3 for backwards com-
patibility with badly-behaved clients. Default is off.
Geometry
This option specifies the screen area that will be
shown to VNC clients. The format is widthxheight+xoff-
set+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
Maximum percentage of CPU time to be consumed when
polling the screen. Default is 35.
PollingCycle
Milliseconds per one polling cycle. Actual interval
may be dynamically adjusted to satisfy MaxProces-
sorUsage setting. Default is 30.
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VideoArea
This option specifies the screen area that will be han-
dled as video. The format is widthxheight+xoff-
set+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 VideoRect-
angleSelection 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).
VideoPriority
Specify the priority of sending video updates. x0vnc-
server can be instructed to treat certain rectangular
part of the screen as a video area and handle it in a
special way for improved performance (see documentation
on the VideoArea parameter). VideoPriority value con-
trols how often video area will be sent to clients as
compared to the rest of the screen. The priority must
be an integer between 0 and 8, and the default value is
2.
VideoPriority set to 1 gives the same priority both to
video and to other pixels. Higher values give more
priority to video. For example, the value 5 specifies
that the rate of sending video will be five times
higher than the rate of updating the rest of the
screen. If VideoPriority is set to 0, it gives equal
priority to video and other updates (just like the
value 1) and also disables special encoding for video
data. In other words, VideoPriority video area will be
sent as a part of other screen contents.
CompareFB
Perform pixel comparison on framebuffer to reduce
unnecessary updates. Default is on.
UseSHM
Use MIT-SHM extension if available. Using that exten-
sion accelerates reading the screen. Default is on.
OverlayMode
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
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(the default X visual often provides 256 colors).
Also, in overlay mode, x0vncserver can show correct
mouse cursor. Default is on.
UseHardwareJPEG
Use hardware-accelerated JPEG compressor for video if
available. x0vncserver can be instructed to treat cer-
tain rectangular part of the screen as a video area and
handle it in a special way for improved performance.
If the client supports Tight encoding and JPEG compres-
sion, such video areas will be sent as JPEG-encoded
rectangles. And if this option is on, compression will
be hardware-accelerated (currently, supported only in
SGI/IRIX equipped with appropriate hardware). Default
is on.
ZlibLevel
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
The number of seconds after which an idle VNC connec-
tion will be dropped (zero means no timeout). Default
is 0.
MaxDisconnectionTime
Terminate when no client has been connected for N sec-
onds. Default is 0.
MaxConnectionTime
Terminate when a client has been connected for N sec-
onds. Default is 0.
MaxIdleTime
Terminate after N seconds of user inactivity. Default
is 0.
ClientWaitTimeMillis
The number of milliseconds to wait for a client which
is no longer responding. Default is 20000.
SEE ALSO
Xvnc(1), vncpasswd(1),
http://www.tigervnc.org/
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AUTHOR
This manual page was written by Constantin Kaplinsky.
ATTRIBUTES
See attributes(5) for descriptions of the following
attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |x11/server/xvnc |
+-----------------------------+-----------------------------+
|Interface Stability |Volatile |
+-----------------------------+-----------------------------+
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