vncviewer(1) Virtual Network Computing vncviewer(1)
vncviewer - VNC viewer for X
vncviewer [options] [host][:display#]
vncviewer [options] [host][::port]
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 argument, e.g.:
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 exam-
ple ":1" means display number 1 on the same machine, and "snoopy" means "snoopy:0" i.e.
display 0 on machine "snoopy".
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 (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 band-
width is insufficient. However, this only occurs when communicating with servers support-
ing protocol 3.8 or newer, since many old servers does not support color mode changes
Automatic selection can be turned off by setting the AutoSelect parameter to false, or
from the options dialog.
The viewer has a popup menu containing entries which perform various actions. It is usu-
ally 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.
Unfortunately this mode doesn't work completely with all window managers, 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 dialog box. This can
be accessed from the popup menu or from the "Connection details" dialog box.
Specifies the X display on which the VNC viewer window should appear.
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 connections with a helper program called vncconfig.
-passwd password-file, -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
Show the dot cursor when the server sends an invisible cursor.
Time in milliseconds to rate-limit successive pointer events.
Try harder to compress data (default).
JPEG quality level (default is 8).
Disable lossy JPEG compression in Tight encoding.
Use specified compression level (default is 2).
Use custom compression level. Default is CompressLevel is specified.
Send the primary selection and cut buffer to the server as well as the clipboard
Send clipboard changes to the server (default).
Accept clipboard changes from the server (default).
When you make a connection to a VNC server, all other existing connections are nor-
mally 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 interfering; often needs to be combined with
Maximize viewer window.
Start in full-screen mode.
Enable full screen over all monitors (default).
Pass special keys directly to the server in full-screen mode.
Dynamically resize the remote desktop size as the size of the local client window
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.
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-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.
This option specifies the preferred encoding to use from one of "Tight", "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 decorations. This is used to
calculate the maximum size of the VNC viewer window. Default is width 6, height
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.
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" - the currently implemented list is: F1,
F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12, Pause, Print, Scroll_Lock, Escape,
Insert, Delete, Home, Page_Up, Page_Down). Default is F8.
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
Zlib compression level.
X509 CRL file
X509 CA certificate
Specify which security scheme to use.
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. TightVNC additions were implemented by Constantin Kaplinsky. Many
other people participated in development, testing and support.
TigerVNC 05 May 2004 vncviewer(1)