.TH vncviewer 1 "" "TigerVNC" "Virtual Network Computing"
.SH NAME
vncviewer \- VNC viewer for X
.SH SYNOPSIS
.B vncviewer
.RI [ options ] 
.RI [ host ][: display# ]
.br
.B vncviewer
.RI [ options ] 
.RI [ host ][:: port ]
.br
.B vncviewer
.RI [ options ]
.RI [ unix\ socket ]
.br
.B vncviewer
.RI [ options ] 
.B \-listen
.RI [ port ]
.br
.B vncviewer
.RI [ options ]
.RI [ .tigervnc\ file ]
.SH DESCRIPTION
.B vncviewer
is a viewer (client) for Virtual Network Computing.  This manual page documents
version 4 for the X window system.

If you run the viewer with no arguments it will prompt you for a VNC server to
connect to.  Alternatively, specify the VNC server as an argument, e.g.:

.RS
vncviewer snoopy:2
.RE

where 'snoopy' is the name of the machine, and '2' is the display number of the
VNC server on that machine.  Either the machine name or display number can be
omitted.  So for example ":1" means display number 1 on the same machine, and
"snoopy" means "snoopy:0" i.e. display 0 on machine "snoopy".

As another quick way to start a connection to a VNC server, specify a .tigervnc
configuration file as an argument to the viewer, e.g.:

.RS
vncviewer ./some.tigervnc
.RE

where './some.tigervnc' is an existing and valid TigerVNC configuration file.
The file name needs to include a path separator.  Additional options may be
given too, but the given configuration file will overwrite any conflicting
parameters.

If the VNC server is successfully contacted, you will be prompted for a
password to authenticate you. You can also add 'VNC_USERNAME' and 'VNC_PASSWORD'
to environment variables. If the password is correct, a window will appear
showing the desktop of the VNC server.

.SH AUTOMATIC PROTOCOL SELECTION

The viewer tests the speed of the connection to the server and chooses the
encoding and pixel format (color level) appropriately.  This makes it much
easier to use than previous versions where the user had to specify arcane
command line arguments.

The viewer normally starts out assuming the link is slow, using the
encoding with the best compression.  If it turns out that the link is
fast enough it switches to an encoding which compresses less but is
faster to generate, thus improving the interactive feel.

The viewer normally starts in full-color mode, but switches to
low-color mode if the bandwidth is insufficient. However, this only
occurs when communicating with servers supporting protocol 3.8 or
newer, since many old servers do not support color mode changes
safely.

Automatic selection can be turned off by setting the
\fBAutoSelect\fP parameter to false, or from the options dialog.

.SH POPUP MENU
The viewer has a popup menu containing entries which perform various actions.
It is usually brought up by pressing F8, but this can be configured with the
MenuKey parameter.  Actions which the popup menu can perform include:
.RS 2
.IP * 2
switching in and out of full-screen mode
.IP *
quitting the viewer
.IP *
generating key events, e.g. sending ctrl-alt-del
.IP *
accessing the options dialog and various other dialogs
.RE
.PP
By default, key presses in the popup menu get sent to the VNC server and
dismiss the popup.  So to get an F8 through to the VNC server simply press it
twice.

.SH FULL-SCREEN MODE
A full-screen mode is supported.  This is particularly useful when connecting
to a remote screen which is the same size as your local one. If the remote
screen is bigger, you can scroll by bumping the mouse against the edge of the
screen.

.SH OPTIONS (PARAMETERS)
You can get a list of parameters by giving \fB\-h\fP as a command-line option
to vncviewer.  Parameters can be turned on with -\fIparam\fP or off with
-\fIparam\fP=0.  Parameters which take a value can be specified as
-\fIparam\fP \fIvalue\fP.  Other valid forms are \fIparam\fP\fB=\fP\fIvalue\fP
-\fIparam\fP=\fIvalue\fP --\fIparam\fP=\fIvalue\fP.  Parameter names are
case-insensitive.

Many of the parameters can also be set graphically via the options dialog box.
This can be accessed from the popup menu or from the "Connection details"
dialog box.

.TP
.B \-display \fIXdisplay\fP
Specifies the X display on which the VNC viewer window should appear.
.
.TP
.B \-geometry \fIgeometry\fP
Initial position of the main VNC viewer window. 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 and the
window will be placed by the window manager by default.
.
.TP
.B \-listen \fI[port]\fP
Causes vncviewer to listen on the given port (default 5500) for reverse
connections from a VNC server.  WinVNC supports reverse connections initiated
using the 'Add new client' menu option or the '\-connect' command-line option.
Xvnc supports reverse connections with a helper program called
.B vncconfig.
.
.TP
.B \-SecurityTypes \fIsec-types\fP
Specify which security schemes to attempt to use when authenticating with
the server.  Valid values are a comma separated list of \fBNone\fP,
\fBVncAuth\fP, \fBPlain\fP, \fBTLSNone\fP, \fBTLSVnc\fP, \fBTLSPlain\fP,
\fBX509None\fP, \fBX509Vnc\fP, \fBX509Plain\fP, \fBRA2\fP, \fBRA2ne\fP,
\fBRA2_256\fP and \fBRA2ne_256\fP. Default is to attempt
every supported scheme. 
.
.TP
.B \-passwd, \-PasswordFile \fIpassword-file\fP
If you are on a filesystem which gives you access to the password file used by
the server, you can specify it here to avoid typing it in.  It will usually be
\fI$XDG_CONFIG_HOME/tigervnc/passwd\fP, or \fI~/.config/tigervnc/passwd\fP
if the former is unset.
.
.TP
.B \-X509CA \fIpath\fP
Path to CA certificate to use when authenticating remote servers using any
of the X509 security schemes (X509None, X509Vnc, etc.). Must be in PEM
format. Default is \fI$XDG_CONFIG_HOME/tigervnc/x509_ca.pem\fP, or
\fI~/.config/tigervnc/x509_ca.pem\fP.
.
.TP
.B \-X509CRL \fIpath\fP
Path to certificate revocation list to use in conjunction with
\fB-X509CA\fP. Must also be in PEM format. Default is
\fI$XDG_CONFIG_HOME/tigervnc/x509_crl.pem\fP, or
\fI~/.config/tigervnc/x509_crl.pem\fP.
.
.TP
.B \-Shared
When you make a connection to a VNC server, all other existing connections are
normally closed.  This option requests that they be left open, allowing you to
share the desktop with someone already using it.
.
.TP
.B \-ViewOnly
Specifies that no keyboard or mouse events should be sent to the server.
Useful if you want to view a desktop without interfering; often needs to be
combined with
.B \-Shared.
.
.TP
.B \-AcceptClipboard
Accept clipboard changes from the server. Default is on.
.
.TP
.B \-SetPrimary
Set the primary selection as well as the clipboard selection.
Default is on.
.
.TP
.B \-MaxCutText \fIbytes\fP
The maximum size of a clipboard update that will be accepted from a server.
Default is \fB262144\fP.
.
.TP
.B \-SendClipboard
Send clipboard changes to the server. Default is on.
.
.TP
.B \-SendPrimary
Send the primary selection to the server as well as the clipboard
selection. Default is on.
.
.TP
.B \-Maximize
Maximize viewer window. 
.
.TP
.B \-FullScreen
Start in full-screen mode.
.
.TP
.B \-FullScreenAllMonitors (DEPRECATED)
Use all local monitors and not just the current one when switching to
full-screen mode. Replaced by \fB-FullScreenMode=all\fP
.
.TP
.B \-FullScreenMode \fImode\fP
Specify which monitors to use when in full screen. It should be either "Current",
"Selected" (specified by \fB-FullScreenSelectedMonitors\fP) or "All". 
The default is "Current".
.
.TP
.B \-FullScreenSelectedMonitors \fImonitors\fP
This option specifies the monitors to use with \fB-FullScreenMode=selected\fP.
Monitors are ordered according to the system configuration from left to right,
and in case of a conflict, from top to bottom. So, for example, "1,2,3" means
that the first, second and third monitor counting from the left should be used.
The default is "1".
.
.TP
.B \-FullscreenSystemKeys
Pass special keys (like Alt+Tab) directly to the server when in full-screen
mode.
.
.TP
.B \-DesktopSize \fIwidth\fPx\fIheight\fP
Instead of keeping the existing remote screen size, the client will attempt to
switch to the specified since when connecting. If the server does not support
the SetDesktopSize message then the screen will retain the original size.
.
.TP
.B \-RemoteResize
Dynamically resize the remote desktop size as the size of the local client
window changes. Note that this may not work with all VNC servers.
.
.TP
.B \-AutoSelect
Use automatic selection of encoding and pixel format (default is on).  Normally
the viewer tests the speed of the connection to the server and chooses the
encoding and pixel format appropriately.  Turn it off with \fB-AutoSelect=0\fP.
.
.TP
.B \-FullColor, \-FullColour
Tells the VNC server to send full-color pixels in the best format for this
display.  This is default. 
.
.TP
.B \-LowColorLevel, \-LowColourLevel \fIlevel\fP
Selects the reduced color level to use on slow links.  \fIlevel\fP can range
from 0 to 2, 0 meaning 8 colors, 1 meaning 64 colors (the default), 2 meaning
256 colors. Note that decision if reduced color level is used is made by
vncviewer. If you would like to force vncviewer to use reduced color level
use \fB-AutoSelect=0\fP parameter.
.
.TP
.B \-PreferredEncoding \fIencoding\fP
This option specifies the preferred encoding to use from one of "Tight", "ZRLE",
"hextile" or "raw".
.
.TP
.B \-NoJpeg
Disable lossy JPEG compression in Tight encoding. Default is off.
.
.TP
.B \-QualityLevel \fIlevel\fP
JPEG quality level. 0 = Low, 9 = High. May be adjusted automatically if
\fB-AutoSelect\fP is turned on. Default is 8.
.
.TP
.B \-CompressLevel \fIlevel\fP
Use specified lossless compression level. 0 = Low, 9 = High. Default is 2.
.
.TP
.B \-CustomCompressLevel
Use custom compression level. Default if \fBCompressLevel\fP is specified.
.
.TP
.B \-DotWhenNoCursor
Show the dot cursor when the server sends an invisible cursor. Default is off.
.
.TP
.B \-PointerEventInterval \fItime\fP
Time in milliseconds to rate-limit successive pointer events. Default is
17 ms (60 Hz).
.
.TP
.B \-EmulateMiddleButton
Emulate middle mouse button by pressing left and right mouse buttons
simultaneously. Default is off.
.
.TP
.B \-Log \fIlogname\fP:\fIdest\fP:\fIlevel\fP
Configures the debug log settings.  \fIdest\fP can currently be \fBstderr\fP or
\fBstdout\fP, and \fIlevel\fP is between 0 and 100, 100 meaning most verbose
output.  \fIlogname\fP is usually \fB*\fP meaning all, but you can target a
specific source file if you know the name of its "LogWriter".  Default is
\fB*:stderr:30\fP.
.
.TP
.B \-MenuKey \fIkeysym-name\fP
This option specifies the key which brings up the popup menu. The currently
supported list is: F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12, Pause,
Scroll_Lock, Escape, Insert, Delete, Home, Page_Up, Page_Down). Default is F8.
.
.TP
\fB\-via\fR \fIgateway\fR
Automatically create encrypted TCP tunnel to the \fIgateway\fR machine
before connection, connect to the \fIhost\fR through that tunnel
(TigerVNC\-specific). By default, this option invokes SSH local port
forwarding, assuming that SSH client binary can be accessed as
/usr/bin/ssh. Note that when using the \fB\-via\fR option, the host
machine name should be specified as known to the gateway machine, e.g. 
"localhost" denotes the \fIgateway\fR, not the machine where vncviewer
was launched. The environment variable \fIVNC_VIA_CMD\fR can override
the default tunnel command of
\fB/usr/bin/ssh\ -f\ -L\ "$L":"$H":"$R"\ "$G"\ sleep\ 20\fR.  The tunnel
command is executed with the environment variables \fIL\fR, \fIH\fR,
\fIR\fR, and \fIG\fR taking the values of the local port number, the remote
host, the port number on the remote host, and the gateway machine
respectively.
.
.TP
.B \-AlertOnFatalError
Display a dialog with any fatal error before exiting. Default is on.
.
.TP
.B \-ReconnectOnError
Display a dialog with any error and offer the possibility to retry
establishing the connection. In case this is off no dialog to
re-connect will be offered. Default is on.

.SH FILES
.TP
\fI$XDG_CONFIG_HOME/tigervnc/default.tigervnc\fP
.TQ
\fI$HOME/.config/tigervnc/default.tigervnc\fP
Default configuration options. This file must have a "magic" first line of
"TigerVNC Configuration file Version 1.0" (without quotes), followed by simple
<setting>=<value> pairs of your choosing. The available settings are those
shown in this man page.
.TP
\fI$XDG_CONFIG_HOME/tigervnc/x509_ca.pem\fP
.TQ
\fI$HOME/.config/tigervnc/x509_ca.pem\fP
Default CA certificate for authenticating servers.
.TP
\fI$XDG_CONFIG_HOME/tigervnc/x509_crl.pem\fP
.TQ
\fI$HOME/.config/tigervnc/x509_crl.pem\fP
Default certificate revocation list.
.TP
\fI$XDG_DATA_HOME/tigervnc/x509_known_hosts\fP
.TQ
\fI$HOME/.local/share/tigervnc/x509_known_hosts\fP
Known hosts database for certificate-based authentication.
.TP
\fI$XDG_STATE_HOME/tigervnc/tigervnc.history\fP
.TQ
\fI$HOME/.local/state/tigervnc/tigervnc.history\fP
History file for hostnames that have been recently connected to.

.SH SEE ALSO
.BR Xvnc (1),
.BR vncpasswd (1),
.BR vncconfig (1),
.BR vncsession (8)
.br
https://www.tigervnc.org

.SH AUTHOR
Tristan Richardson, RealVNC Ltd. 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.