unix/x0vncserver/x0vncserver.man

.TH X0VNCSERVER 1 "" "TigerVNC" "TigerVNC Manual"
.SH NAME
x0vncserver \- TigerVNC Server for X displays
.SH SYNOPSIS
.B x0vncserver
.RI [ options ]
.br
.B x0vncserver -version
.SH DESCRIPTION
.B x0vncserver
is a TigerVNC Server which makes any X display remotely accessible via VNC,
TigerVNC 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).

XDamage will be used if the existing X server supports it. Otherwise
.B x0vncserver
will fall back to polling the screen for changes.
.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 a comma separated list of \fBNone\fP, \fBVncAuth\fP, \fBPlain\fP,
\fBTLSNone\fP, \fBTLSVnc\fP, \fBTLSPlain\fP, \fBX509None\fP, \fBX509Vnc\fP
and \fBX509Plain\fP. Default is \fBVncAuth,TLSVnc\fP.
.TP
.B rfbauth, 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 PlainUsers
A comma separated list of user names that are allowed to authenticate via
any of the "Plain" security types (Plain, TLSPlain, etc.). Specify \fB*\fP
to allow any user to authenticate using this security type. Default is to
deny all users.
.TP
.B pam_service
PAM service name to use when authentication users using any of the "Plain"
security types. Default is \fBvnc\fP.
.TP
.B x509cert
Path to a X509 certificate in PEM format to be used for all X509 based
security types (X509None, X509Vnc, etc.).
.TP
.B x509key
Private key counter part to the certificate given in \fBx509cert\fP. Must
also be in PEM format.
.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 VideoArea
This option specifies the screen area that will be handled as video.  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).  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
\fBVideoArea\fP parameter will take effect.  If the argument is empty, no
video area is set (this is the default).
.TP
.B DeferUpdate
x0vncserver uses a "deferred update" mechanism which enhances performance in
many cases. After any change to the framebuffer, x0vncserver waits for this
number of milliseconds (default 1) before sending an update to any waiting
clients. This means that more changes tend to get coalesced together in a
single update. Setting it to 0 results in the same behaviour as earlier
versions of x0vncserver, where the first change to the framebuffer causes an
immediate update to any waiting clients.
.TP
.B AlwaysSetDeferUpdateTimer
Keep delaying sending the screen update to the client(s) each time the
screen is updated. Otherwise the delay is from the first update. Default
is off.
.TP
.B CompareFB
Perform pixel comparison on framebuffer to reduce unnecessary updates. Can
be either \fB0\fP (off), \fB1\fP (always) or \fB2\fP (auto). Default is
\fB2\fP.
.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 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.
.TP
.B AcceptCutText
.TQ
.B SendCutText
.TQ
.B MaxCutText
Currently unused.
.SH SEE ALSO
.BR Xvnc (1),
.BR vncpasswd (1),
.br
http://www.tigervnc.org/
.SH 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.