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


       vncviewer  is  an  Xt-based client application for the VNC
       (Virtual Network Computing) system. It can connect to  any
       VNC-compatible server such as Xvnc or WinVNC, allowing you
       to control desktop environment of a different machine.

       You can use F8 to display a pop-up utility menu. Press  F8
       twice to pass single F8 to the remote side.


       -help  Prints a short usage notice to stderr.

              Make  the  viewer  listen  on port 5500+display for
              reverse connections from a server. WinVNC  supports
              reverse connections using the "Add New Client" menu
              option, or the -connect command line  option.  Xvnc
              requires  the use of the helper program vncconnect.

       -via gateway
              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 for­
              warding, 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 speci­
              fied as known to the gateway machine, e.g.  "local­
              host" denotes the gateway, not  the  machine  where
              vncviewer was launched. See the ENVIRONMENT section
              below for the information on configuring  the  -via

              When  connecting,  specify that a shared connection
              is requested. In  TightVNC,  this  is  the  default
              mode,  allowing you to share the desktop with other
              clients already using it.

              When connecting, specify that the session  may  not
              be  shared. This would either disconnect other con­
              nected clients or refuse your connection, depending
              on the server configuration.

              on  remote  beep (bell) event. This option disables
              such behaviour (TightVNC-specific).

       -passwd passwd-file
              File from which to get the password  (as  generated
              by the vncpasswd(1) program).

       -encodings encoding-list
              TightVNC  supports  several  different  compression
              methods to encode screen updates; this option spec­
              ifies  a set of them to use in order of preference.
              Encodings are specified separated with spaces,  and
              must thus be enclosed in quotes if more than one is
              specified. Available encodings,  in  default  order
              for  a  remote connection, are "copyrect tight hex­
              tile zlib corre rre raw". For  a  local  connection
              (to  the same machine), the default order to try is
              "raw copyrect tight hextile zlib  corre  rre".  Raw
              encoding  is  always assumed as a last option if no
              other encoding can be used  for  some  reason.  For
              more  information  on  encodings,  see  the section
              ENCODINGS below.

              Always use the BGR233 format to encode pixel  data.
              This  reduces  network  traffic,  but colors may be
              represented inaccurately. The bgr233 format  is  an
              8-bit "true color" format, with 2 bits blue, 3 bits
              green, and 3 bits red.

              Try to use a PseudoColor visual and a private  col­
              ormap.  This  allows  the VNC server to control the

       -truecolour, -truecolor
              Try to use a TrueColor visual.

       -depth depth
              On an X server which  supports  multiple  TrueColor
              visuals  of  different  depths,  attempt to use the
              specified one (in bits per pixel);  if  successful,
              this depth will be requested from the VNC server.

       -compresslevel level
              Use  specified compression level (0..9) for "tight"
              and "zlib" encodings (TightVNC-specific).  Level  1
              uses minimum of CPU time and achieves weak compres­
              sion ratios, while level 9 offers best  compression
              but is slow in terms of CPU time consumption on the
              server side. Use high levels with very slow network
              connections,  and  low  levels  when  working  over

              Disable lossy JPEG compression  in  Tight  encoding
              (TightVNC-specific).  Disabling JPEG compression is
              not a good idea in typical cases, as that makes the
              Tight encoder less efficient. You might want to use
              this option if it's absolutely necessary to achieve
              perfect   image  quality  (see  also  the  -quality

              Disable cursor shape updates,  protocol  extensions
              used  to  handle remote cursor movements locally on
              the client side (TightVNC-specific).  Using  cursor
              shape  updates  decreases delays with remote cursor
              movements, and can improve bandwidth usage dramati­

              Use  a  real  X11  cursor with X-style cursor shape
              updates, instead of drawing the  remote  cursor  on
              the  framebuffer. This option also disables the dot
              cursor, and disables  cursor  position  updates  in
              non-fullscreen mode.


       The  server  supplies  information  in  whatever format is
       desired by the client, in order to make the client as easy
       as possible to implement.  If the client represents itself
       as able to use multiple formats, the  server  will  choose

       Pixel format refers to the representation of an individual
       pixel.  The  most  common  formats  are  24  and  16   bit
       "true-color"  values,  and  8-bit  "color map" representa­
       tions, where an arbitrary map converts the color number to
       RGB values.

       Encoding refers to how a rectangle of pixels are sent (all
       pixel information in VNC is sent as rectangles). All rect­
       angles  come with a header giving the location and size of
       the rectangle and an encoding type used by the data  which
       follows. These types are listed below.

       Raw    The  raw  encoding  simply sends width*height pixel
              values. All clients are required  to  support  this
              encoding  type.  Raw  is  also the fastest when the
              server and viewer are on the same machine,  as  the
              connection  speed  is  essentially infinite and raw
              encoding minimizes processing time.


       CoRRE  This is a minor variation on RRE, using  a  maximum
              of  255x255  pixel rectangles. This allows for sin­
              gle-byte values to be used, reducing  packet  size.
              This is in general more efficient, because the sav­
              ings from sending 1-byte values generally outweighs
              the  losses  from the (relatively rare) cases where
              very large regions are painted the same color.

              Here, rectangles are split up in  to  16x16  tiles,
              which  are  sent in a predetermined order. The data
              within the tiles is sent either raw or as a variant
              on RRE. Hextile encoding is usually the best choice
              for using in high-speed network environments  (e.g.
              Ethernet local-area networks).

       Zlib   Zlib  is  a  very  simple  encoding  that uses zlib
              library to compress raw pixel data.  This  encoding
              achieves  good  compression,  but consumes a lot of
              CPU time. Support for this encoding is provided for
              compatibility  with  VNC  servers  that  might  not
              understand Tight encoding which is  more  efficient
              than Zlib in nearly all real-life situations.

       Tight  Like   Zlib  encoding,  Tight  encoding  uses  zlib
              library to compress the pixel data, but it pre-pro­
              cesses  data to maximize compression ratios, and to
              minimize CPU usage on compression. Also, JPEG  com­
              pression  may  be  used to encode color-rich screen
              areas (see the description of -quality and  -nojpeg
              options  above). Tight encoding is usually the best
              choice for low-bandwidth network environments (e.g.
              slow modem connections).


       X  resources  that  vncviewer  knows about, aside from the
       normal Xt resources, are as follows:

              Equivalent of  -shared/-noshared  options.  Default

              Equivalent of -viewonly option. Default false.

              Equivalent of -fullscreen option. Default false.

              Grab keyboard in full-screen mode. This can help to
              solve problems with losing keyboard focus.  Default

              Equivalent of -encodings option.

              Equivalent of -compresslevel option  (TightVNC-spe­

              Equivalent  of -quality option (TightVNC-specific).

              Equivalent of -nojpeg option, when  set  to  false.
              Default true.

              Equivalent  of  -nocursorshape  option, when set to
              false (TightVNC-specific). Default true.

              Equivalent of -bgr233 option. Default false.

              When  using  BGR233,  try  to  allocate  this  many
              "exact"  colors  from  the  BGR233 color cube. When
              using a  shared  colormap,  setting  this  resource
              lower  leaves  more  colors  for  other  X clients.
              Irrelevant when using  truecolor.  Default  is  256
              (i.e. all of them).

              If the number of "exact" BGR233 colors successfully
              allocated is less than 256 then the rest are filled
              in  using  the  "nearest"  colors  available.  This
              resource says  whether  to  only  use  the  "exact"
              BGR233  colors  for this purpose, or whether to use
              other clients' "shared"  colors  as  well.  Default
              true (i.e. use other clients' colors).

              Equivalent of -owncmap option. Default false.

              Equivalent of -truecolour option. Default false.

              Equivalent of -depth option.

              Use  MIT  shared  memory  extension  if on the same
              machine as the X server. Default true.

       wmDecorationWidth, wmDecorationHeight

              The number of buttons in the popup window. See  the
              README  file  for  more  information on how to cus­
              tomize the buttons.

       debug  For debugging. Default false.

       rawDelay, copyRectDelay
              For debugging, see the  README  file  for  details.
              Default 0 (off).


       When  started  with  the  -via option, vncviewer reads the
       VNC_VIA_CMD environment variable, expands patterns  begin­
       ning with the "%" character, and executes result as a com­
       mand assuming that it would create TCP tunnel that  should
       be  used  for VNC connection. If not set, this environment
       variable defaults to "/usr/bin/ssh -f -L %L:%H:%R %G sleep

       The  following  patterns are recognized in the VNC_VIA_CMD
       (note that all the patterns %G, %H, %L and %R must be pre­
       sent in the command template):

       %%     A literal "%";

       %G     gateway host name;

       %H     remote VNC host name, as known to the gateway;

       %L     local TCP port number;

       %R     remote TCP port number.


       vncserver(1), Xvnc(1), vncpasswd(1), vncconnect(1), ssh(1)


       Original VNC was developed in AT&T Laboratories Cambridge.
       TightVNC  additions  was implemented by Constantin Kaplin­
       sky. Many other people participated in development,  test­
       ing and support.

       Man page authors:
       Marcus Brinkmann <Marcus.Brinkmann@ruhr-uni-bochum.de>,
       Terran Melconian <terran@consistent.org>,
       Tim Waugh <twaugh@redhat.com>,
       Constantin Kaplinsky <const@ce.cctpu.edu.ru>




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