vncviewer(1) Virtual Network Computing vncviewer(1)

NAME

vncviewer - VNC viewer for X

SYNOPSIS

vncviewer [options] [host][:display#]
vncviewer [options] [host][::port]
vncviewer [options] [unix socket]
vncviewer [options] -listen [port]
vncviewer [options] [.tigervnc file]

DESCRIPTION

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.:

vncviewer snoopy:2

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.:

vncviewer ./some.tigervnc

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.

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 does not support color mode changes
safely.

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

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:

* switching in and out of full-screen mode

* quitting the viewer

* generating key events, e.g. sending ctrl-alt-del

* accessing the options dialog and various other dialogs

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.


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.


OPTIONS (PARAMETERS)
You can get a list of parameters by giving -h as a command-line
option to vncviewer. Parameters can be turned on with -param or off
with -param=0. Parameters which take a value can be specified as
-param value. Other valid forms are param=value -param=value
--param=value. 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.


-display Xdisplay
Specifies the X display on which the VNC viewer window should
appear.

-geometry geometry
Initial position of the main VNC viewer window. 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 and the window
will be placed by the window manager by default.

-listen [port]
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 vncconfig.

-SecurityTypes sec-types
Specify which security schemes to attempt to use when
authenticating with the server. Valid values are a comma
separated list of None, VncAuth, Plain, TLSNone, TLSVnc,
TLSPlain, X509None, X509Vnc, X509Plain, RA2, RA2ne, RA2_256
and RA2ne_256. Default is to attempt every supported scheme.

-passwd, -PasswordFile password-file
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 "~/.vnc/passwd".

-X509CA path
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
$HOME/.vnc/x509_ca.pem.

-X509CRL path
Path to certificate revocation list to use in conjunction with
-X509CA. Must also be in PEM format. Default is
$HOME/.vnc/x509_crl.pem.

-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.

-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 -Shared.

-AcceptClipboard
Accept clipboard changes from the server. Default is on.

-SetPrimary
Set the primary selection as well as the clipboard selection.
Default is on.

-MaxCutText bytes
The maximum size of a clipboard update that will be accepted
from a server. Default is 262144.

-SendClipboard
Send clipboard changes to the server. Default is on.

-SendPrimary
Send the primary selection to the server as well as the
clipboard selection. Default is on.

-Maximize
Maximize viewer window.

-FullScreen
Start in full-screen mode.

-FullScreenAllMonitors (DEPRECATED)
Use all local monitors and not just the current one when
switching to full-screen mode. Replaced by -FullScreenMode=all

-FullScreenMode mode
Specify which monitors to use when in full screen. It should
be either "Current", "Selected" (specified by
-FullScreenSelectedMonitors) or "All". The default is
"Current".

-FullScreenSelectedMonitors monitors
This option specifies the monitors to use with
-FullScreenMode=selected. 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".

-FullscreenSystemKeys
Pass special keys (like Alt+Tab) directly to the server when
in full-screen mode.

-DesktopSize widthxheight
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.

-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.

-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 -AutoSelect=0.

-FullColor, -FullColour
Tells the VNC server to send full-color pixels in the best
format for this display. This is default.

-LowColorLevel, -LowColourLevel level
Selects the reduced color level to use on slow links. level
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
-AutoSelect=0 parameter.

-PreferredEncoding encoding
This option specifies the preferred encoding to use from one
of "Tight", "ZRLE", "hextile" or "raw".

-NoJpeg
Disable lossy JPEG compression in Tight encoding. Default is
off.

-QualityLevel level
JPEG quality level. 0 = Low, 9 = High. May be adjusted
automatically if -AutoSelect is turned on. Default is 8.

-CompressLevel level
Use specified lossless compression level. 0 = Low, 9 = High.
Default is 2.

-CustomCompressLevel
Use custom compression level. Default if CompressLevel is
specified.

-DotWhenNoCursor
Show the dot cursor when the server sends an invisible cursor.
Default is off.

-PointerEventInterval time
Time in milliseconds to rate-limit successive pointer events.
Default is 17 ms (60 Hz).

-EmulateMiddleButton
Emulate middle mouse button by pressing left and right mouse
buttons simultaneously. Default is off.

-Log logname:dest:level
Configures the debug log settings. dest can currently be
stderr or stdout, and level is between 0 and 100, 100 meaning
most verbose output. logname is usually * meaning all, but
you can target a specific source file if you know the name of
its "LogWriter". Default is *:stderr:30.

-MenuKey keysym-name
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.

-via gateway
Automatically create encrypted TCP tunnel to the gateway
machine before connection, connect to the host 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 -via
option, the host machine name should be specified as known to
the gateway machine, e.g. "localhost" denotes the gateway,
not the machine where vncviewer was launched. The environment
variable VNC_VIA_CMD can override the default tunnel command
of /usr/bin/ssh -f -L "$L":"$H":"$R" "$G" sleep 20. The
tunnel command is executed with the environment variables L,
H, R, and G taken the values of the local port number, the
remote host, the port number on the remote host, and the
gateway machine respectively.

-AlertOnFatalError
Display a dialog with any fatal error before exiting. Default
is on.

-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.

FILES

$HOME/.vnc/default.tigervnc
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.

$HOME/.vnc/x509_ca.pem
Default CA certificate for authenticating servers.

$HOME/.vnc/x509_crl.pem
Default certificate revocation list.

SEE ALSO

Xvnc(1), vncpasswd(1), vncconfig(1), vncsession(8)
https://www.tigervnc.org

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.

TigerVNC vncviewer(1)