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ssvncviewer(1)			     SSVNC			ssvncviewer(1)

       ssvncviewer - an	X viewer client	for VNC

       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] unix=/path/to/unix/socket
       ssvncviewer [options] -listen [display]
       ssvncviewer -help

       ssvncviewer is an Xt-based client application for the VNC (Virtual Net-
       work Computing) system. It can connect  to  any	VNC-compatible	server
       such  as	Xvnc, WinVNC, or x11vnc, allowing you to control desktop envi-
       ronment 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 (also  F7  on  MacOSX.)
       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 connec-
	      tions 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 ma-
	      chine, 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.

	      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 connected clients or	refuse
	      your connection, depending on the	server configuration.

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

	      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  set-
	      ting  in the RESOURCES section below for a method	to solve input
	      focus problem.

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

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

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

       -encodings encoding-list
	      TightVNC	supports  several different compression	methods	to en-
	      code 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 en-
	      codings, 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 be-

	      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 colormap. This al-
	      lows 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 dif-
	      ferent  depths,  attempt	to  use	the specified one (in bits per
	      pixel); if successful, this depth	will be	requested from the VNC

       -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  rec-
	      ommended	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"  en-
	      coding  (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.

	      Disable lossy JPEG compression in	Tight encoding	(TightVNC-spe-
	      cific).	Disabling JPEG compression is not a good idea in typi-
	      cal 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).

	      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

	      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  up-
	      dates in non-fullscreen mode.

	      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:

       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_MULTI-
	      PLE_LISTEN=MAX:n to allow	no more	than "n" simultaneous  reverse

	      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	exter-
	      nal  command, e.g. an stunnel(8) that does not involve a listen-
	      ing socket.  This	mode does not work for -listen reverse connec-
	      tions.	To  not	 have  the  exec=  pid	killed	at  exit,  set

	      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 '/' and exists in the	file system it
	      is interpreted as	a unix-domain socket (AF_LOCAL/AF_UNIX instead
	      of AF_INET)  Prefix with unix=  to  force	 interpretation	 as  a
	      unix-domain socket.

	      As  in  -listen (reverse connection listening) except allow more
	      than one incoming	VNC server to be connected at a	time.  The de-
	      fault 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

	      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.

	      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.

	      Same as -use64.

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

	      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.

	      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 en-

       -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 re-
	      quires 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.

	      Disable bell.

	      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.

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

	      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)

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

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

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

	      Grab the X keyboard when in fullscreen mode, needed by some win-
	      dow 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 pix-
	      els. 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)

	      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, new-
	      line 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

	      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 pre-
	      fixed by "rm:" the file is removed after reading.	Otherwise,  if
	      str  has a "@" character,	it is taken as username@password. Oth-
	      erwise, the program exits	with an	error. Got all that?

       -repeater str
	      This is for use with UltraVNC  repeater  proxy  described	 here:	  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. or  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

	      Example: vncviewer ... -repeater vhost:0

	      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.

	      UltraVNC	has  symmetric	private	 encryption  DSM plugins.  See  It	is assumed you
	      are  using  a unix program (e.g. our ultravnc_dsm_helper)	to en-
	      crypt 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	Ultra-
	      VNC 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 en-
	      tire VNC session.

	      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,

	      Disable all IPv6 sockets.	 Same as VNCVIEWER_NO_IPV6=1.

	      Disable all IPv4 sockets.	 Same as VNCVIEWER_NO_IPV4=1.

	      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 XAP-

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

	      Enable  features	for use	with x11vnc's -appshare	mode where in-
	      stead of sharing the full	desktop	only the application's windows
	      are  shared.  Viewer multilisten mode is used to create the mul-
	      tiple 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_APP-
	      SHARE_CMD:  message  channel,  x11vnc  initial  window  position
	      hints.   See also	Escape Keys below for additional key and mouse

       -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

	      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  de-
	      fault  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  key-

	      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,

	      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

	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 al-
	       Grey scale (16 &	8-bpp)	~ -grey, for low colors	16/8bpp	 modes
	       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
		 Single	Window		  Ultravnc ext.	Grab and view a	single
					  (select then click on	the window you
		 Disable Remote	Input	  Ultravnc ext.	Try to	prevent	 input
					  viewing  of monitor at physical dis-

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

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

       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	infor-
       mation 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.

	      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 iden-
	      tical  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 con-
	      stant 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.

	      Here, rectangles are split up in to 16x16	tiles, which are  sent
	      in  a predetermined order. The data within the tiles is sent ei-
	      ther 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  com-
	      press  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 un-
	      derstand 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  compres-
	      sion  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 net-
	      work environments	(e.g. slow modem connections).

       ZRLE   The  SSVNC  viewer has ported the	RealVNC	( ZRLE
	      encoding to the unix tightvnc viewer.

       ZYWRLE The SSVNC	viewer has ported the Hitachi lossy wavelet based ZRLE
	      encoding	   from
	      tions/ZYWRLE/ to the unix	tightvnc viewer.

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

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

	      Equivalent of -viewonly option. Default false.

	      Equivalent of -fullscreen	option.	Default	false.

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

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

	      Equivalent of -passwd option.

	      Equivalent of -user option.

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

	      Equivalent of -encodings option.

	      Equivalent of -compresslevel option (TightVNC-specific).

	      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.  Ir-
	      relevant	when  using  truecolor.	 Default  is  256 (i.e.	all of

	      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 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 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.

	      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).

       When started with the -via option, vncviewer reads the VNC_VIA_CMD  en-
       vironment  variable, expands patterns beginning with the	"%" character,
       and executes result as a	command	assuming that it would create TCP tun-
       nel  that  should be used for VNC connection. If	not set, this environ-
       ment 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 tem-

       %%     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),  x11vnc(1),   ssvnc(1),   Xvnc(1),	  vncpasswd(1),	  vnc-
       connect(1),  ssh(1),, http://www.karl-

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

       Man page	authors:
       Marcus Brinkmann	<>,
       Terran Melconian	<>,
       Tim Waugh <>,
       Constantin Kaplinsky <>
       Karl J. Runge <>

				  April	2010			ssvncviewer(1)


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