vncviewer(1) Virtual Network Computing vncviewer(1)
vncviewer - VNC viewer for X
vncviewer [options] [host][:display#]
vncviewer [options] -listen [port]
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
where ’snoopy’ is the name of the machine, and ’2’ is the display num-
ber of the VNC server on that machine. Either the machine name or dis-
play 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
If the VNC server is successfully contacted, you will be prompted for a
password to authenticate you. 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 (colour 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 a low
colour level and using the encoding with the best compression. If it
turns out that the link is fast enough it switches to full-colour mode
and will use an encoding which compresses less but is faster to gener-
ate, thus improving the interactive feel. Automatic selection can be
turned off by setting the AutoSelect parameter to false, or from the
The viewer has a popup menu containing entries which perform various
actions. It is usually brought up by pressing F8, but this can be con-
figured with the MenuKey parameter. Actions which the popup menu can
* 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 sim-
ply press it twice.
FULL SCREEN MODE
A full-screen mode is supported. This is particularly useful when con-
necting 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.
Unfortunately this mode doesn’t work completely with all window man-
agers, since it breaks the X window management conventions.
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 dia-
log box. This can be accessed from the popup menu or from the "Connec-
tion details" dialog box.
Specifies the X display on which the VNC viewer window should
Standard X position and sizing specification.
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 con-
nections with a helper program called vncconfig.
If you are on a filesystem which gives you access to the pass-
word file used by the server, you can specify it here to avoid
typing it in. It will usually be "~/.vnc/passwd".
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.
Specifies that no keyboard or mouse events should be sent to the
server. Useful if you want to view a desktop without interfer-
ing; often needs to be combined with -Shared.
Start in full-screen mode.
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.
Tells the VNC server to send full-colour pixels in the best for-
mat for this display. By default a low colour mode is used
until AutoSelect decides the link is fast enough. However if
the server’s native pixel format is colourmapped (as opposed to
truecolour) then the server’s format is used by default.
Selects the reduced colour level to use on slow links. level
can range from 0 to 2, 0 meaning 8 colours, 1 meaning 64 colours
(the default), 2 meaning 256 colours.
This option specifies the preferred encoding to use from one of
"ZRLE", "hextile" or "raw".
Render the mouse cursor locally if the server supports it
(default is on). This can make the interactive performance feel
much better over slow links.
-WMDecorationWidth w, -WMDecorationHeight h
The total width and height taken up by window manager decora-
tions. This is used to calculate the maximum size of the VNC
viewer window. Default is width 6, height 24.
Configures the debug log settings. dest can currently be stderr
or stdout, and level is between 0 and 100, 100 meaning most ver-
bose output. logname is usually * meaning all, but you can tar-
get a specific source file if you know the name of its "Log-
Writer". Default is *:stderr:30.
This option specifies the key which brings up the popup menu.
The key is specified as an X11 keysym name (these can be
obtained by removing the XK_ prefix from the entries in
"/usr/include/X11/keysymdef.h"). Default is F8.
Automatically create encrypted TCP tunnel to the gateway machine
before connection, connect to the host through that tunnel
(TightVNC-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
Xvnc(1), vncpasswd(1), vncconfig(1), vncserver(1)
Tristan Richardson, RealVNC Ltd.
VNC was originally developed by the RealVNC team while at Olivetti
Research Ltd / AT&T Laboratories Cambridge. It is now being maintained
by RealVNC Ltd. See http://www.realvnc.com for details.
RealVNC Ltd 03 Mar 2005 vncviewer(1)
Man(1) output converted with