tigervnc/unix/x0vncserver/x0vncserver.man

.TH X0VNCSERVER 1 "January  7, 2008" "TightVNC" "TightVNC Manual"
.SH NAME
x0vncserver \- TightVNC Server for real X displays
.SH SYNOPSIS
.B x0vncserver
.RI [ options ]
.SH DESCRIPTION
.B x0vncserver
is a TightVNC Server which makes any X display remotely accessible via VNC,
TightVNC or compatible viewers.  Unlike \fBXvnc\fP(1), it does not create a
virtual display.  Instead, it just shares an existing X server (typically,
that one connected to the physical screen).
.SH OPTIONS
.B x0vncserver
interprets the command line as a list of parameters with optional values.
Running \fBx0vncserver -h\fP will show a list of all valid parameters with
short descriptions.  All parameters are optional, but normally you would have
to use the \fBPasswordFile\fP parameter (see its description below).
.PP
There are several forms of specifying parameters in the command line (here we
use `\fISomeParameter\fP' as an example parameter name):
.TP
.B -\fISomeParameter\fP
Enable the parameter, turn the feature on.  This form can be used with
parameters that simply enable or disable some feature.
.TP
.B -\fISomeParameter\fP=0
Disable the parameter, turn the feature off.
.TP
.B -\fISomeParameter\fP=\fIvalue\fP
Assign the specified \fIvalue\fP to the parameter.  The leading dash can be
omitted, or it can be doubled if desired (like in GNU-style long options).
.PP
Parameter names are case-insensitive, their order in the command line can be
arbitrary.
.SH PARAMETERS
.TP
.B display
The X display name.  If not specified, it defaults to the value of the
DISPLAY environment variable.
.TP
.B rfbport
TCP port to listen for incoming VNC connections (RFB protocol).  The default
port is 5900.
.TP
.B Log
Specifies which log output should be directed to which target logger, and the
level of output to log.  Format is \fIlog\fP:\fItarget\fP:\fIlevel\fP.
Default is \fB*:stderr:30\fP (log everything to stderr, set log level to 30).
Log level should be a value between 0 and 100, higher levels produce more
output.
.TP
.B 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: +\fIaddress\fP/\fInetmask\fP (accept connections from the
specified address group), -\fIaddress\fP/\fInetmask\fP (reject connections)
or ?\fIaddress\fP/\fInetmask\fP (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.
\fINetmask\fP 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.
.TP
.B SecurityTypes
Specify which security scheme to use for incoming connections.  Valid values
are \fBNone\fP and \fBVncAuth\fP.  Default is \fBVncAuth\fP.
.TP
.B PasswordFile
Password file for VNC authentication.  There is no default, you should
specify the password file explicitly.  Password file should be created with
the \fBvncpasswd\fP(1) utility.
.TP
.B Password
Obfuscated binary encoding of the password which clients must supply to
access the server.  Using this parameter is insecure, use \fBPasswordFile\fP
parameter instead.
.TP
.B BlacklistThreshold
The number of unauthenticated connection attempts allowed from any individual
host before that host is black-listed.  Default is 5.
.TP
.B 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.
.TP
.B QueryConnect
Prompt the local user to accept or reject incoming connections.  Default is
off.
.TP
.B QueryConnectTimeout
Number of seconds to show the Accept Connection dialog before rejecting the
connection.  Default is 10.
.TP
.B AlwaysShared
Always treat incoming connections as shared, regardless of the
client-specified setting.  Default is off.
.TP
.B NeverShared
Never treat incoming connections as shared, regardless of the
client-specified setting.  Default is off.
.TP
.B DisconnectClients
Disconnect existing clients if an incoming connection is non-shared.  If
combined with \fBNeverShared\fP then new connections will be refused while
there is a client active.  Default is on.
.TP
.B AcceptKeyEvents
Accept key press and release events from clients.  Default is on.
.TP
.B AcceptPointerEvents
Accept pointer events from clients.  Default is on.
.TP
.B RemapKeys
Comma-separated list of incoming keysyms to remap.  Mappings are expressed as
two hex values, prefixed by \fB0x\fP, and separated by \fB->\fP (`dash' and
`greater than' characters).
.TP
.B Protocol3.3
Always use RFB protocol version 3.3 for backwards compatibility with
badly-behaved clients.  Default is off.
.TP
.B Geometry
This option specifies the screen area that will be shown to VNC clients.  The
format is
.B \fIwidth\fPx\fIheight\fP+\fIxoffset\fP+\fIyoffset\fP
, 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).
.TP
.B MaxProcessorUsage
Maximum percentage of CPU time to be consumed when polling the
screen.  Default is 35.
.TP
.B PollingCycle
Milliseconds per one polling cycle.  Actual interval may be dynamically
adjusted to satisfy \fBMaxProcessorUsage\fP setting.  Default is 30.
.TP
.B VideoPriority
Specify the priority of sending video area updates.  \fBx0vncserver\fP can
detect video areas on the screen and handle them separately for improved
performance.  This parameter controls 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.

\fBVideoPriority\fP set to 0 disables video detection completely, so
\fBx0vncserver\fP will not use any video-specific tricks.

The value 1 gives the same priority both to video and to other pixels.  That
differs from the value 0 \- overall performance can be much better if there
is some video on the screen. That's because video-specific polling and
encoding algorithms can be used.

Higher values give more priority to video.  For example, \fBVideoPriority\fP
set to 5 specifies that the rate of sending video will be five times higher
than the rate of updating the rest of the screen.

\fBNote:\fP with high \fBVideoPriority\fP values, video detection will work
slower.  For example, when the video area was moved, this fact will be
discovered with a longer delay.  That's because high priority values make the
server send video with highest rate possible, without spending time on
polling and video detection.
.TP
.B CompareFB
Perform pixel comparison on framebuffer to reduce unnecessary updates.
Default is on.
.TP
.B UseSHM
Use MIT-SHM extension if available.  Using that extension accelerates reading
the screen.  Default is on.
.TP
.B 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 (the default X visual often provides 256 colors).  Also, in overlay
mode, \fBx0vncserver\fP can show correct mouse cursor.  Default is on.
.TP
.B UseHardwareJPEG
Use hardware-accelerated JPEG compressor for video if available.
\fBx0vncserver\fP can detect video areas on the screen and handle them
separately from the rest of the screen, for better performance.  If the
client supports Tight encoding and JPEG compression, 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.
.TP
.B 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 \fBzlib\fP(3) compression library.
.TP
.B 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.
.TP
.B IdleTimeout
The number of seconds after which an idle VNC connection will be dropped
(zero means no timeout).  Default is 0.
.TP
.B MaxDisconnectionTime
Terminate when no client has been connected for \fIN\fP seconds.  Default is
0.
.TP
.B MaxConnectionTime
Terminate when a client has been connected for \fIN\fP seconds.  Default is
0.
.TP
.B MaxIdleTime
Terminate after \fIN\fP seconds of user inactivity.  Default is 0.
.TP
.B ClientWaitTimeMillis
The number of milliseconds to wait for a client which is no longer
responding.  Default is 20000.
.SH SEE ALSO
.BR Xvnc (1),
.BR vncpasswd (1),
.br
http://www.tightvnc.com/
.SH AUTHOR
This manual page was written by Constantin Kaplinsky.