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man pages section 1: User Commands

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Updated: Wednesday, February 10, 2021

vncviewer (1)


vncviewer - VNC viewer for X


vncviewer [options] [host][:display#]
vncviewer [options] [host][::port]
vncviewer [options] -listen [port]


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.:

              vncviewer snoopy:2

       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
       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.

       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 parame-
       ter to false, or from the options dialog.

       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
       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  sim-
       ply press it twice.

       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.

       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.

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

       -geometry geometry
              Standard X position and sizing specification.

       -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  con-
              nections with a helper program called vncconfig.

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

       -passwd, -PasswordFile password-file
              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".

       -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,
              if it exists.

       -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, if it exists.

              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.

              Accept clipboard changes from the server. Default is on.

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

              Send clipboard changes to the server. Default is on.

              Send the primary selection to the server as well  as  the  clip-
              board selection. Default is on.

              Maximize viewer window.

              Start in full-screen mode.

              Use all local monitors and not just the current one when switch-
              ing to full-screen mode.

              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.

              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.

              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  appropri-
              ately.  Turn it off with -AutoSelect=0.

       -FullColor, -FullColour
              Tells  the VNC server to send full-color pixels in the best for-
              mat 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

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

              Disable lossy JPEG compression in  Tight  encoding.  Default  is

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

       -CompressLevel level
              Use specified lossless compression level. 0 =  Low,  6  =  High.
              Default is 2.

              Use custom compression level. Default if CompressLevel is speci-

              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 to send events immediately.

       -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 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.

       -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, Print,  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

              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

              Default CA certificate for authenticating servers.

              Default certificate revocation list.

       See attributes(7) for descriptions of the following attributes:

       |ATTRIBUTE TYPE |        ATTRIBUTE VALUE          |
       |Availability   | desktop/remote-desktop/tigervnc |
       |Stability      | Volatile                        |
       Xvnc(1), vncpasswd(1), vncconfig(1), vncserver(1)

       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  par-
       ticipated  in  development, testing and support. This manual is part of
       the TigerVNC software suite.

       This    software    was    built    from    source     available     at
       https://github.com/oracle/solaris-userland.    The  original  community
       source was  downloaded  from   https://github.com/TigerVNC/tigervnc/ar-

       Further information about this software can be found on the open source
       community website at http://tigervnc.org/.

TigerVNC                                                          vncviewer(1)