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NAME

       ssvncviewer - an X viewer client for VNC

SYNOPSIS

       ssvncviewer [options] [host][:display]
       ssvncviewer [options] [host][::port]
       ssvncviewer [options] exec=[cmd+args...]
       ssvncviewer [options] fd=n
       ssvncviewer [options] /path/to/unix/socket
       ssvncviewer [options] -listen [display]
       ssvncviewer -help

DESCRIPTION

       ssvncviewer  is  an  Xt-based  client  application for the VNC (Virtual
       Network Computing) system. It can connect to any VNC-compatible  server
       such  as  Xvnc,  WinVNC,  or  x11vnc,  allowing  you to control desktop
       environment of a different machine.

       ssvncviewer is an enhanced version of the tightvnc unix viewer that can
       take advantage of features in the x11vnc and UltraVNC VNC servers.  See
       below for the description of these features.

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

OPTIONS

       -help  Prints a short usage notice to stderr.

       -listen
              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 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. See the ENVIRONMENT section  below
              for the information on configuring the -via option.

       -shared
              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.

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

       -viewonly
              Disable transfer of mouse and keyboard events from the client to
              the server.

       -fullscreen
              Start in full-screen mode. Please be  aware  that  operating  in
              full-screen  mode may confuse X window managers. Typically, such
              conflicts cause incorrect handling of input focus  or  make  the
              viewer  window  disappear  mysteriously.  See  the  grabKeyboard
              setting in the RESOURCES section below for  a  method  to  solve
              input focus problem.

       -noraiseonbeep
              By  default,  the  viewer  shows and raises its window on remote
              beep  (bell)  event.  This  option   disables   such   behaviour
              (TightVNC-specific).

       -user username
              User  name  for  Unix  login  authentication.  Default is to use
              current Unix user name. If this option  was  given,  the  viewer
              will  prefer  Unix  login  authentication  over the standard VNC
              authentication.

       -passwd passwd-file
              File from which  to  get  the  password  (as  generated  by  the
              vncpasswd(1) program). This option affects only the standard VNC
              authentication.

       -encodings encoding-list
              TightVNC  supports  several  different  compression  methods  to
              encode  screen  updates;  this option specifies 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.   Commas  may  be  used  to  avoid   spaces.
              Available  encodings,  in default order for a remote connection,
              are "copyrect tight hextile 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.

       -bgr233
              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.

       -owncmap
              Try to use a PseudoColor visual and  a  private  colormap.  This
              allows the VNC server to control the colormap.

       -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 compression 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  high-speed LANs. It’s not
              recommended to use compression level 0, reasonable choices start
              from the level 1.

       -quality level
              Use  the  specified  JPEG  quality  level (0..9) for the "tight"
              encoding (TightVNC-specific). Quality level 0 denotes bad  image
              quality  but  very  impressive compression ratios, while level 9
              offers very good image quality at lower compression ratios. Note
              that  the  "tight" encoder uses JPEG to encode only those screen
              areas that look suitable for lossy compression, so quality level
              0 does not always mean unacceptable image quality.

       -nojpeg
              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 option).

       -nocursorshape
              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
              dramatically.

       -x11cursor
              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.

       -autopass
              Read  a plain-text password from stdin. This option affects only
              the standard VNC authentication.

Enhanced TightVNC Viewer (SSVNC) OPTIONS

       Enhanced TightVNC Viewer (SSVNC) web page is located at:

       http://www.karlrunge.com/x11vnc/ssvnc.html

       Note: ZRLE and ZYWRLE encodings are now supported.

       Note: F9 is shortcut to Toggle FullScreen mode.

       Note: In -listen mode set the env var. SSVNC_MULTIPLE_LISTEN=1
              to allow more than one incoming VNC server at a time.   This  is
              the    same    as    -multilisten    described    below.     Set
              SSVNC_MULTIPLE_LISTEN=MAX:n  to   allow   no   more   than   "n"
              simultaneous reverse connections.

              If  the  host:port  is specified as "exec=command args..."  then
              instead of making a TCP/IP socket connection to the  remote  VNC
              server, "command args..." is executed and the viewer is attached
              to its  stdio.   This  enables  tunnelling  established  via  an
              external  command,  e.g.  an  stunnel(8) that does not involve a
              listening socket.  This mode does not work for  -listen  reverse
              connections.

              If  the host:port is specified as "fd=n" then it is assumed n is
              an already opened file descriptor to the socket. (i.e the parent
              did fork+exec)

              If  the  host:port  contains  a ’/’ it is interpreted as a unix-
              domain socket (AF_LOCAL insead of AF_INET)

       -multilisten
              As in -listen (reverse connection listening) except  allow  more
              than  one  incoming  VNC  server to be connected at a time.  The
              default for -listen of only one at a time tries to play it  safe
              by  not allowing anyone on the network to put (many) desktops on
              your screen over a long window of time. Use -multilisten for  no
              limit.

       -acceptpopup
              In  -listen  (reverse  connection listening) mode when a reverse
              VNC connection comes in show a popup asking whether to Accept or
              Reject the connection.  The IP address of the connecting host is
              shown.  Same as setting the env. var. SSVNC_ACCEPT_POPUP=1.

       -acceptpopupsc
              As in -acceptpopup except  assume  UltraVNC  Single  Click  (SC)
              server.   Retrieve  User  and  ComputerName  info  from UltraVNC
              Server and display in the Popup.

       -use64 In -bgr233 mode, use 64 colors instead of 256.

       -bgr222
              Same as -use64.

       -use8  In -bgr233 mode, use 8 colors instead of 256.

       -bgr111
              Same as -use8.

       -16bpp If the vnc viewer X display is depth 24 at 32bpp request a 16bpp
              format  from  the VNC server to cut network traffic by up to 2X,
              then tranlate the pixels to 32bpp locally.

       -bgr565
              Same as -16bpp.

       -grey  Use a grey scale for the 16- and 8-bpp modes.

       -alpha Use  alphablending  transparency  for  local  cursors  requires:
              x11vnc  server,  both  client  and server must be 32bpp and same
              endianness.

       -scale str
              Scale the desktop locally.  The  string  "str"  can  a  floating
              point ratio, e.g. "0.9", or a fraction, e.g. "3/4", or WxH, e.g.
              1280x1024.  Use "fit" to fit in the current  screen  size.   Use
              "auto"  to fit in the window size.  "str" can also be set by the
              env. var. SSVNC_SCALE.

              If you observe mouse trail painting errors,  enable  X11  Cursor
              mode (either via Popup or -x11cursor.)

              Note  that  scaling  is  done in software and so can be slow and
              requires more memory.  Some speedup Tips:

              ZRLE is faster than Tight in this mode.  When scaling  is  first
              detected,  the  encoding will be automatically switched to ZRLE.
              Use the Popup menu if  you  want  to  go  back  to  Tight.   Set
              SSVNC_PRESERVE_ENCODING=1 to disable this.

              Use  a  solid  background on the remote side.  (e.g. manually or
              via x11vnc -solid ...)

              If the remote server is x11vnc, try client side caching:  x11vnc
              -ncache 10 ...

       -ycrop n
              Only  show  the  top  n  rows  of the framebuffer.  For use with
              x11vnc -ncache client caching option to help  "hide"  the  pixel
              cache region.  Use a negative value (e.g. -1) for autodetection.
              Autodetection will always take place if the remote fb height  is
              more than 2 times the width.

       -sbwidth n
              Scrollbar  width  for  x11vnc  -ncache mode (-ycrop), default is
              very narrow: 2 pixels, it is  narrow  to  avoid  distraction  in
              -ycrop mode.

       -nobell
              Disable bell.

       -rawlocal
              Prefer  raw  encoding for localhost, default is no, i.e. assumes
              you have a SSH tunnel instead.

       -notty Try to avoid using the terminal for interactive  responses:  use
              windows  for messages and prompting instead.  Messages will also
              be printed to terminal.

       -sendclipboard
              Send the X CLIPBOARD selection (i.e. Ctrl+C, Ctrl+V) instead  of
              the  X PRIMARY selection (mouse select and middle button paste.)

       -sendalways
              Whenever the mouse enters the VNC viewer main window,  send  the
              selection to the VNC server even if it has not changed.  This is
              like the Xt resource translation SelectionToVNC(always)

       -recvtext
              str   When cut text is received from the VNC server, ssvncviewer
              will   set  both  the  X  PRIMARY  and  the  X  CLIPBOARD  local
              selections.   To  control  which  is  set,  specify   ’str’   as
              ’primary’, ’clipboard’, or ’both’ (the default.)

       -graball
              Grab the entire X server when in fullscreen mode, needed by some
              old window managers like fvwm2.

       -popupfix
              Warp the popup back to the pointer position, needed by some  old
              window managers like fvwm2.

       -grabkbd
              Grab  the  X  keyboard  when  in fullscreen mode, needed by some
              window  managers.  Same  as  -grabkeyboard.   -grabkbd  is   the
              default, use -nograbkbd to disable.

       -bs, -nobs
              Whether  or not to use X server Backingstore for the main viewer
              window.  The default is to not, mainly because most Linux,  etc,
              systems  X  servers  disable  *all* Backingstore by default.  To
              re-enable it put

              Option "Backingstore"

              in the Device section of /etc/X11/xorg.conf.  In -bs  mode  with
              no  X  server  backingstore,  whenever  an area of the screen is
              re-exposed it must go out to the  VNC  server  to  retrieve  the
              pixels. This is too slow.

              In  -nobs mode, memory is allocated by the viewer to provide its
              own backing of the main viewer window. This actually makes  some
              activities  faster  (changes in large regions) but can appear to
              "flash" too much.

       -noshm Disable use of MIT shared memory extension (not recommended)

       -termchat
              Do the UltraVNC chat in the terminal vncviewer is in instead  of
              in an independent window.

       -unixpw str
              Useful  for  logging  into  x11vnc  in  -unixpw mode. "str" is a
              string that allows many ways to enter the Unix Username and Unix
              Password.    These   characters:  username,  newline,  password,
              newline are sent to the VNC server after any VNC  authentication
              has  taken  place.   Under  x11vnc they are used for the -unixpw
              login.  Other VNC servers could do something similar.

              You  can  also  indicate  "str"  via  the  environment  variable
              SSVNC_UNIXPW.

              Note  that  the Escape key is actually sent first to tell x11vnc
              to not echo the Unix  Username  back  to  the  VNC  viewer.  Set
              SSVNC_UNIXPW_NOESC=1 to override this.

              If str is ".", then you are prompted at the command line for the
              username and password in the normal way.   If  str  is  "-"  the
              stdin  is  read via getpass(3) for username@password.  Otherwise
              if str is a file, it is opened and the first line read is  taken
              as  the  Unix  username  and  the  2nd  as  the password. If str
              prefixed by "rm:" the file is removed after reading.  Otherwise,
              if  str  has  a "@" character, it is taken as username@password.
              Otherwise, the program exits with an error. Got all that?

       -repeater str
              This is for use with UltraVNC  repeater  proxy  described  here:
              http://www.uvnc.com/addons/repeater.html.   The  "str" is the ID
              string to be sent to the repeater.  E.g. ID:1234 It can also  be
              the  hostname  and  port  or  display  of  the  VNC server, e.g.
              12.34.56.78:0 or snoopy.com:1.  Note that when using  -repeater,
              the  host:dpy on the cmdline is the repeater server, NOT the VNC
              server.  The repeater will connect you.

              Example: vncviewer ... -repeater ID:3333 repeat.host:5900

              Example: vncviewer ... -repeater vhost:0 repeat.host:5900

              Use, e.g., ’-repeater SCIII=ID:3210’ if the repeater is a Single
              Click  III (SSL) repeater (repeater_SSL.exe) and you are passing
              the SSL part of the  connection  through  stunnel,  socat,  etc.
              This  way  the magic UltraVNC string ’testB’ needed to work with
              the repeater is sent to it.

       -rfbversion str
              Set the advertised RFB version.  E.g.: -rfbversion 3.6  For some
              servers, e.g. UltraVNC this needs to be done.

       -ultradsm
              UltraVNC  has  symmetric  private  encryption  DSM plugins.  See
              http://www.uvnc.com/features/encryption.html.  It is assumed you
              are  using  a  unix  program  (e.g.  our ultravnc_dsm_helper) to
              encrypt and decrypt the UltraVNC DSM stream. IN ADDITION TO THAT
              supply -ultradsm to tell THIS viewer to modify the RFB data sent
              so as to work with the UltraVNC Server.  For some  reason,  each
              RFB msg type must be sent twice under DSM.

       -mslogon user
              Use Windows MS Logon to an UltraVNC server.  Supply the username
              or "1" to  be  prompted.   The  default  is  to  autodetect  the
              UltraVNC  MS  Logon  server  and  prompt  for  the  username and
              password.

              IMPORTANT NOTE: The UltraVNC MS-Logon Diffie-Hellman exchange is
              very  weak  and can be brute forced to recover your username and
              password in a few seconds of CPU time.  To be safe, be  sure  to
              use  an  additional  encrypted  tunnel (e.g. SSL or SSH) for the
              entire VNC session.

       -chatonly
              Try to be a client that only does UltraVNC text chat. This  mode
              is  used  by x11vnc to present a chat window on the physical X11
              console (i.e. to chat with the person at the display).

       -env VAR=VALUE
              To save writing a shell script  to  set  environment  variables,
              specify  as  many as you need on the command line.  For example,
              -env SSVNC_MULTIPLE_LISTEN=MAX:5 -env EDITOR=vi

       -noipv6
              Disable all IPv6 sockets.  Same as VNCVIEWER_NO_IPV6=1.

       -noipv4
              Disable all IPv4 sockets.  Same as VNCVIEWER_NO_IPV4=1.

       -printres
              Print out the Ssvnc X resources (appdefaults) and then exit. You
              can save them to a file and customize them (e.g. the keybindings
              and Popup menu)  Then point to  the  file  via  XENVIRONMENT  or
              XAPPLRESDIR.

       -pipeline
              Like  TurboVNC,  request  the next framebuffer update as soon as
              possible instead  of  waiting  until  the  end  of  the  current
              framebuffer  update  coming  in.   Helps ’pipeline’ the updates.
              This is currently the default, use -nopipeline to disable.

       -appshare
              Enable features for  use  with  x11vnc’s  -appshare  mode  where
              instead  of  sharing  the  full  desktop  only the application’s
              windows are shared.  Viewer multilisten mode is used  to  create
              the  multiple  windows:  -multilisten  is  implied.  See ’x11vnc
              -appshare -help’ more information on the mode.  Features enabled
              in  the  viewer  under  -appshare are: Minimum extra text in the
              title,  auto   -ycrop   is   disabled,   x11vnc   -remote_prefix
              X11VNC_APPSHARE_CMD:  message  channel,  x11vnc  initial  window
              position hints.  See also Escape Keys below for  additional  key
              and mouse bindings.

       -escape str
              This sets the ’Escape Keys’ modifier sequence and enables escape
              keys mode.  When the modifier keys escape sequence is held down,
              the  next  keystroke is interpreted locally to perform a special
              action instead of being sent to the remote VNC server.

              Use ’-escape default’ for the default modifier sequence.  (Unix:
              Alt_L,Super_L and MacOSX: Control_L,Meta_L)

              Here  are  the  ’Escape  Keys:  Help+Set’  instructions from the
              Popup:

              Escape Keys:  Enter a comma separated list of modifier  keys  to
              be  the  ’escape  sequence’.  When these keys are held down, the
              next keystroke is interpreted locally to invoke a special action
              instead of being sent to the remote VNC server.  In other words,
              a set of ’Hot Keys’.

              Here is the list of local key mappings to special actions:

              r: refresh desktop  b: toggle bell  c: toggle full-color

              f: file transfer    x: x11cursor    z: toggle Tight/ZRLE

              l: full screen      g: graball      e: escape keys dialog

              s: scale dialog     +: scale up (=) -: scale down (_)

              t: text chat                        a: alphablend cursor

              V: toggle viewonly  Q: quit viewer  123456: UltraVNC scale 1/n

              Arrow keys: pan the viewport about 10% for each keypress.

              PageUp/PageDown: pan the viewport by a screenful vertically.

              Home/End: pan the viewport by a screenful horizontally.

              KeyPad Arrows: pan the viewport by 1 pixel for each keypress.

              Dragging the Mouse with Button1 pressed also pans the  viewport.

              Clicking Mouse Button3 brings up the Popup Menu.

              The  above  mappings  are always active in ViewOnly mode, unless
              you set the Escape Keys value to ’never’.

              x11vnc -appshare hot-keys:   x11vnc  has  a  simple  application
              sharing  mode  that  enables the viewer-side to move, resize, or
              raise the remote toplevel windows.   To  enable  it,  hold  down
              Shift + the Escape Keys and press these:

              Arrow keys: move the remote window around in its desktop.

              PageUp/PageDn/Home/End:  resize the remote window.

              +/-: raise or lower the remote window.

              M  or  Button1 move win to local position;  D or Button3: delete
              remote win.

              If the Escape Keys value  below  is  set  to  ’default’  then  a
              default  list  of  of  modifier  keys  is used.  For Unix it is:
              Alt_L,Super_L and for MacOSX it is Control_L,Meta_L.  Note:  the
              Super_L key usually has a Windows(TM) Flag on it.  Also note the
              _L and _R mean the key is on the  LEFT  or  RIGHT  side  of  the
              keyboard.

              On  Unix    the  default is Alt and Windows keys on Left side of
              keyboard.  On MacOSX the default is Control and Command keys  on
              Left side of keyboard.

              Example:  Press  and  hold  the Alt and Windows keys on the LEFT
              side of the keyboard and then press ’c’ to toggle the full-color
              state.   Or  press  ’t’ to toggle the ultravnc Text Chat window,
              etc.

              To use something besides the default, supply a  comma  separated
              list (or a single one) from: Shift_L Shift_R Control_L Control_R
              Alt_L Alt_R Meta_L Meta_R Super_L  Super_R  Hyper_L  Hyper_R  or
              Mode_switch.

        New Popup actions:

               ViewOnly:                ~ -viewonly
               Disable Bell:            ~ -nobell
               Cursor Shape:            ~ -nocursorshape
               X11 Cursor:              ~ -x11cursor
               Cursor Alphablend:       ~ -alpha
               Toggle Tight/Hextile:    ~ -encodings hextile...
               Toggle Tight/ZRLE:       ~ -encodings zrle...
               Toggle ZRLE/ZYWRLE:      ~ -encodings zywrle...
               Quality Level            ~ -quality (both Tight and ZYWRLE)
               Compress Level           ~ -compresslevel
               Disable JPEG:            ~ -nojpeg  (Tight)
               Pipeline Updates         ~ -pipeline

               Full  Color                  as  many  colors  as  local screen
              allows.
               Grey scale (16 & 8-bpp)  ~ -grey, for low colors 16/8bpp  modes
              only.
               16 bit color (BGR565)    ~ -16bpp / -bgr565
               8  bit color (BGR233)    ~ -bgr233
               256 colors               ~ -bgr233 default # of colors.
                64 colors               ~ -bgr222 / -use64
                 8 colors               ~ -bgr111 / -use8
               Scale Viewer             ~ -scale
               Escape Keys: Toggle      ~ -escape
               Escape Keys: Help+Set    ~ -escape
               Set Y Crop (y-max)       ~ -ycrop
               Set Scrollbar Width      ~ -sbwidth
               XGrabServer              ~ -graball

               UltraVNC Extensions:

                 Set  1/n Server Scale     Ultravnc ext. Scale desktop by 1/n.
                 Text Chat                Ultravnc ext. Do Text Chat.
                 File Transfer            Ultravnc ext.  File  xfer  via  Java
              helper.
                 Single Window            Ultravnc ext. Grab and view a single
              window.
                                          (select then click on the window you
              want).
                 Disable  Remote  Input     Ultravnc ext. Try to prevent input
              and
                                          viewing  of  monitor   at   physical
              display.

               Note:  the  Ultravnc  extensions  only  apply  to  servers that
              support
                     them.  x11vnc/libvncserver supports some of them.

               Send Clipboard not Primary  ~ -sendclipboard
               Send Selection Every time   ~ -sendalways

ENCODINGS

       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 one.

       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" representations, 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 rectangles 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.

       CopyRect
              The Copy Rectangle encoding is efficient when something is being
              moved; the only data sent is the location of  a  rectangle  from
              which  data  should  be copied to the current location. Copyrect
              could also be used to efficiently transmit a repeated pattern.

       RRE    The Rise-and-Run-length-Encoding is basically a  2D  version  of
              run-length  encoding  (RLE).  In  this  encoding,  a sequence of
              identical pixels are compressed to a  single  value  and  repeat
              count.  In VNC, this is implemented with a background color, and
              then specifications of an arbitrary number of subrectangles  and
              color  for  each. This is an efficient encoding for large blocks
              of constant color.

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

       Hextile
              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-processes  data  to  maximize
              compression ratios, and to minimize CPU  usage  on  compression.
              Also,  JPEG  compression 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).

       ZRLE   The  SSVNC  viewer has ported the RealVNC (www.realvnc.com) ZRLE
              encoding to the unix tightvnc viewer.

       ZYWRLE The SSVNC viewer has ported the Hitachi lossy wavelet based ZRLE
              encoding               from               http://mobile.hitachi-
              system.co.jp/publications/ZYWRLE/ to the unix tightvnc viewer.

RESOURCES

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

       shareDesktop
              Equivalent of -shared/-noshared options. Default true.

       viewOnly
              Equivalent of -viewonly option. Default false.

       fullScreen
              Equivalent of -fullscreen option. Default false.

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

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

       passwordFile
              Equivalent of -passwd option.

       userLogin
              Equivalent of -user option.

       passwordDialog
              Whether to use a dialog box to get the password (true) or get it
              from the tty (false). Irrelevant if passwordFile is set. Default
              false.

       encodings
              Equivalent of -encodings option.

       compressLevel
              Equivalent of -compresslevel option (TightVNC-specific).

       qualityLevel
              Equivalent of -quality option (TightVNC-specific).

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

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

       useBGR233
              Equivalent of -bgr233 option. Default false.

       nColours
              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).

       useSharedColours
              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).

       forceOwnCmap
              Equivalent of -owncmap option. Default false.

       forceTrueColour
              Equivalent of -truecolour option. Default false.

       requestedDepth
              Equivalent of -depth option.

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

       wmDecorationWidth, wmDecorationHeight
              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 4, height 24.

       bumpScrollTime, bumpScrollPixels
              When in full screen mode and the VNC desktop is bigger than  the
              X display, scrolling happens whenever the mouse hits the edge of
              the screen. The maximum speed of scrolling  is  bumpScrollPixels
              pixels  every  bumpScrollTime  milliseconds. The actual speed of
              scrolling will be slower than this, of course, depending on  how
              fast  your machine is.  Default 20 pixels every 25 milliseconds.

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

       debug  For debugging. Default false.

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

ENVIRONMENT

       When started with the -via  option,  vncviewer  reads  the  VNC_VIA_CMD
       environment   variable,   expands   patterns  beginning  with  the  "%"
       character, and executes result as a  command  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 20".

       The following patterns are recognized in the VNC_VIA_CMD (note that all
       the patterns %G,  %H,  %L  and  %R  must  be  present  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.

SEE ALSO

       vncserver(1),     x11vnc(1),     ssvnc(1),    Xvnc(1),    vncpasswd(1),
       vncconnect(1),         ssh(1),         http://www.karlrunge.com/x11vnc,
       http://www.karlrunge.com/x11vnc/ssvnc.html

AUTHORS

       Original  VNC  was  developed  in AT&T Laboratories Cambridge. TightVNC
       additions was implemented by Constantin Kaplinsky.  Many  other  people
       participated  in development, testing and support.  Karl J. Runge added
       all of the SSVNC related features and improvements.

       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>
       Karl J. Runge <runge@karlrunge.com>

                                  April 2010                    ssvncviewer(1)