path: root/x11vnc/x11vnc.1

.\" This file was automatically generated from x11vnc -help output.
.TH X11VNC "1" "December 2004" "x11vnc " "User Commands"
.SH NAME
x11vnc - allow VNC connections to real X11 displays
         version: 0.6.3pre, lastmod: 2004-12-17
.SH SYNOPSIS
.B x11vnc
[OPTION]...
.SH DESCRIPTION
.PP
Typical usage is:
.IP
Run this command in a shell on the remote machine "far-host"
with X session you wish to view:
.IP
x11vnc -display :0
.IP
Then run this in another window on the machine you are sitting at:
.IP
vncviewer far-host:0
.PP
Once x11vnc establishes connections with the X11 server and starts listening
as a VNC server it will print out a string: PORT=XXXX where XXXX is typically
5900 (the default VNC server port).  One would next run something like
this on the local machine: "vncviewer hostname:N" where "hostname" is
the name of the machine running x11vnc and N is XXXX - 5900, i.e. usually
"vncviewer hostname:0".
.PP
By default x11vnc will not allow the screen to be shared and it will exit
as soon as a client disconnects.  See \fB-shared\fR and \fB-forever\fR below to override
these protections.  See the FAQ on how to tunnel the VNC connection through
an encrypted channel such as 
.IR ssh (1).
.PP
For additional info see: http://www.karlrunge.com/x11vnc/
and  http://www.karlrunge.com/x11vnc/#faq
.PP
Rudimentary config file support: if the file $HOME/.x11vncrc exists then each
line in it is treated as a single command line option.  Disable with \fB-norc.\fR
For each option name, the leading character "-" is not required.  E.g. a
line that is either "nap" or "\fB-nap\fR" may be used and are equivalent.
Likewise "wait 100" or "\fB-wait\fR \fI100\fR" are acceptable and equivalent lines.
The "#" character comments out to the end of the line in the usual way.
Leading and trailing whitespace is trimmed off.  Lines may be continued with
a "\\" as the last character of a line (it becomes a space character).
.PP
.SH OPTIONS

.PP
\fB-display\fR \fIdisp\fR
.IP
X11 server display to connect to, usually :0.  The X
server process must be running on same machine and
support MIT-SHM.  Equivalent to setting the DISPLAY
environment variable to \fIdisp\fR.
.PP
\fB-auth\fR \fIfile\fR
.IP
Set the X authority file to be \fIfile\fR, equivalent to
setting the XAUTHORITY environment varirable to \fIfile\fR
before startup.  See 
.IR Xsecurity (7)
, 
.IR xauth (1)
man pages.
.PP
\fB-id\fR \fIwindowid\fR
.IP
Show the window corresponding to \fIwindowid\fR not
the entire display.  New windows like popup menus,
transient toplevels, etc, may not be seen or may be
clipped.  Disabling SaveUnders or BackingStore in the
X server may help show them.  x11vnc may crash if the
window is initially partially obscured, changes size,
is iconified, etc.  Some steps are taken to avoid this
and the \fB-xrandr\fR mechanism is used to track resizes.  Use
.IR xwininfo (1)
to get the window id, or use "\fB-id\fR \fIpick\fR"
to have x11vnc run 
.IR xwininfo (1)
for you and extract
the id.  The \fB-id\fR option is useful for exporting very
simple applications (e.g. the current view on a webcam).
.PP
\fB-sid\fR \fIwindowid\fR
.IP
As \fB-id,\fR but instead of using the window directly it
shifts a root view to it: this shows SaveUnders menus,
etc, although they will be clipped if they extend beyond
the window.
.PP
\fB-flashcmap\fR
.IP
In 8bpp indexed color, let the installed colormap flash
as the pointer moves from window to window (slow).
.PP
\fB-notruecolor\fR
.IP
For 8bpp displays, force indexed color (i.e. a colormap)
even if it looks like 8bpp TrueColor. (rare problem)
.PP
\fB-visual\fR \fIn\fR
.IP
Experimental option: probably does not do what you
think.  It simply *forces* the visual used for the
framebuffer; this may be a bad thing... (e.g. messes
up colors or cause a crash). It is useful for testing
and for some workarounds.  n may be a decimal number,
or 0x hex.  Run 
.IR xdpyinfo (1)
for the values.  One may
also use "TrueColor", etc. see <X11/X.h> for a list.
If the string ends in ":m" for better or for worse
the visual depth is forced to be m.
.PP
\fB-overlay\fR
.IP
Handle multiple depth visuals on one screen, e.g. 8+24
and 24+8 overlay visuals (the 32 bits per pixel are
packed with 8 for PseudoColor and 24 for TrueColor).
.IP
Currently \fB-overlay\fR only works on Solaris via
.IR XReadScreen (3X11)
and IRIX using 
.IR XReadDisplay (3).
On Solaris there is a problem with image "bleeding"
around transient popup menus (but not for the menu
itself): a workaround is to disable SaveUnders
by passing the "\fB-su\fR" argument to Xsun (in
/etc/dt/config/Xservers).  Also note that the mouse
cursor shape is exactly correct in this mode.
.IP
Use \fB-overlay\fR as a workaround for situations like these:
Some legacy applications require the default visual to
be 8bpp (8+24), or they will use 8bpp PseudoColor even
when the default visual is depth 24 TrueColor (24+8).
In these cases colors in some windows will be messed
up in x11vnc unless \fB-overlay\fR is used.  Another use of
\fB-overlay\fR is to enable showing the exact mouse cursor
shape (details below).
.IP
Under \fB-overlay,\fR performance will be somewhat degraded
due to the extra image transformations required.
For optimal performance do not use \fB-overlay,\fR but rather
configure the X server so that the default visual is
depth 24 TrueColor and try to have all apps use that
visual (some apps have \fB-use24\fR or \fB-visual\fR options).
.PP
\fB-overlay_nocursor\fR
.IP
Sets \fB-overlay,\fR but does not try to draw the exact mouse
cursor shape using the overlay mechanism.
.PP
\fB-scale\fR \fIfraction\fR
.IP
Scale the framebuffer by factor \fIfraction\fR.  Values
less than 1 shrink the fb, larger ones expand it.
Note: image may not be sharp and response may be
slower.  Currently the cursor shape is not scaled.
If \fIfraction\fR contains a decimal point "." it
is taken as a floating point number, alternatively
the notation "m/n" may be used to denote fractions
exactly, e.g. \fB-scale\fR 2/3.
.IP
Scaling Options: can be added after \fIfraction\fR via
":", to supply multiple ":" options use commas.
If you just want a quick, rough scaling without
blending, append ":nb" to \fIfraction\fR (e.g. \fB-scale\fR
1/3:nb).  For compatibility with vncviewers the scaled
width is adjusted to be a multiple of 4: to disable
this use ":n4".  More esoteric options: ":in" use
interpolation scheme even when shrinking, ":pad",
pad scaled width and height to be multiples of scaling
denominator (e.g. 3 for 2/3).
.PP
\fB-viewonly\fR
.IP
All VNC clients can only watch (default off).
.PP
\fB-shared\fR
.IP
VNC display is shared (default off).
.PP
\fB-once\fR
.IP
Exit after the first successfully connected viewer
disconnects, opposite of \fB-forever.\fR This is the Default.
.PP
\fB-forever\fR
.IP
Keep listening for more connections rather than exiting
as soon as the first client(s) disconnect. Same as \fB-many\fR
.PP
\fB-inetd\fR
.IP
Launched by 
.IR inetd (1):
stdio instead of listening socket.
Note: if you are not redirecting stderr to a log file
(via shell 2> or \fB-o\fR option) you must also specify the
\fB-q\fR option, otherwise the stderr goes to the viewer.
.PP
\fB-connect\fR \fIstring\fR
.IP
For use with "vncviewer -listen" reverse connections.
If \fIstring\fR has the form "host" or "host:port"
the connection is made once at startup.  Use commas
for a list of host's and host:port's.  If \fIstring\fR
contains "/" it is instead interpreted as a file to
periodically check for new hosts.  The first line is
read and then the file is truncated.
.PP
\fB-vncconnect,\fR \fB-novncconnect\fR
.IP
Monitor the VNC_CONNECT X property set by the standard
VNC program 
.IR vncconnect (1).
When the property is
set to "host" or "host:port" establish a reverse
connection.  Using 
.IR xprop (1)
instead of vncconnect may
work (see the FAQ).  Default: \fB-vncconnect\fR
.PP
\fB-allow\fR \fIhost1[,host2..]\fR
.IP
Only allow client connections from hosts matching
the comma separated list of hostnames or IP addresses.
Can also be a numerical IP prefix, e.g. "192.168.100."
to match a simple subnet, for more control build
libvncserver with libwrap support (See the FAQ).  If the
list contains a "/" it instead is a interpreted as a
file containing addresses or prefixes that is re-read
each time a new client connects.  Lines can be commented
out with the "#" character in the usual way.
.PP
\fB-localhost\fR
.IP
Same as \fB-allow\fR 127.0.0.1
.PP
\fB-viewpasswd\fR \fIstring\fR
.IP
Supply a 2nd password for view-only logins.  The \fB-passwd\fR
(full-access) password must also be supplied.
.PP
\fB-passwdfile\fR \fIfilename\fR
.IP
Specify libvncserver \fB-passwd\fR via the first line of
the file \fIfilename\fR instead of via command line.
If a second non blank line exists in the file it is
taken as a view-only password (i.e. \fB-viewpasswd)\fR Note:
this is a simple plaintext passwd, see also \fB-rfbauth\fR
and \fB-storepasswd\fR below for obfuscated passwords.
.PP
\fB-storepasswd\fR \fIpass\fR \fIfile\fR
.IP
Store password \fIpass\fR as the VNC password in the
file \fIfile\fR.  Once the password is stored the
program exits.  Use the password via "\fB-rfbauth\fR \fIfile\fR"
.PP
\fB-accept\fR \fIstring\fR
.IP
Run a command (possibly to prompt the user at the
X11 display) to decide whether an incoming client
should be allowed to connect or not.  \fIstring\fR is
an external command run via 
.IR system (3)
or some special
cases described below.  Be sure to quote \fIstring\fR
if it contains spaces, shell characters, etc.  If the
external command returns 0 the client is accepted,
otherwise the client is rejected.  See below for an
extension to accept a client view-only.
.IP
Environment: The RFB_CLIENT_IP environment variable will
be set to the incoming client IP number and the port
in RFB_CLIENT_PORT (or -1 if unavailable).  Similarly,
RFB_SERVER_IP and RFB_SERVER_PORT (the x11vnc side
of the connection), are set to allow identification
of the tcp virtual circuit.  The x11vnc process
id will be in RFB_X11VNC_PID, a client id number in
RFB_CLIENT_ID, and the number of other connected clients
in RFB_CLIENT_COUNT.  RFB_MODE will be "accept"
.IP
If \fIstring\fR is "popup" then a builtin popup window
is used.  The popup will time out after 120 seconds,
use "popup:N" to modify the timeout to N seconds
(use 0 for no timeout)
.IP
If \fIstring\fR is "xmessage" then an 
.IR xmessage (1)
invocation is used for the command.  xmessage must be
installed on the machine for this to work.
.IP
Both "popup" and "xmessage" will present an option
for accepting the client "View-Only" (the client
can only watch).  This option will not be presented if
\fB-viewonly\fR has been specified, in which case the entire
display is view only.
.IP
If the user supplied command is prefixed with something
like "yes:0,no:*,view:3 mycommand ..." then this
associates the numerical command return code with
the actions: accept, reject, and accept-view-only,
respectively.  Use "*" instead of a number to indicate
the default action (in case the command returns an
unexpected value).  E.g. "no:*" is a good choice.
.IP
Note that x11vnc blocks while the external command
or popup is running (other clients may see no updates
during this period).
.IP
More \fB-accept\fR tricks: use "popupmouse" to only allow
mouse clicks in the builtin popup to be recognized.
Similarly use "popupkey" to only recognize
keystroke responses.  These are to help avoid the
user accidentally accepting a client by typing or
clicking. All 3 of the popup keywords can be followed
by +N+M to supply a position for the popup window.
The default is to center the popup window.
.PP
\fB-gone\fR \fIstring\fR
.IP
As \fB-accept,\fR except to run a user supplied command when
a client goes away (disconnects).  RFB_MODE will be
set to "gone" and the other RFB_* variables are as
in \fB-accept.\fR  Unlike \fB-accept,\fR the command return code
is not interpreted by x11vnc.  Example: \fB-gone\fR 'xlock &'
.PP
\fB-noshm\fR
.IP
Do not use the MIT-SHM extension for the polling.
Remote displays can be polled this way: be careful this
can use large amounts of network bandwidth.  This is
also of use if the local machine has a limited number
of shm segments and \fB-onetile\fR is not sufficient.
.PP
\fB-flipbyteorder\fR
.IP
Sometimes needed if remotely polled host has different
endianness.  Ignored unless \fB-noshm\fR is set.
.PP
\fB-onetile\fR
.IP
Do not use the new copy_tiles() framebuffer mechanism,
just use 1 shm tile for polling.  Limits shm segments
used to 3.
.PP
\fB-blackout\fR \fIstring\fR
.IP
Black out rectangles on the screen. \fIstring\fR is a
comma separated list of WxH+X+Y type geometries for
each rectangle.
.PP
\fB-xinerama\fR
.IP
If your screen is composed of multiple monitors
glued together via XINERAMA, and that screen is
non-rectangular this option will try to guess the
areas to black out (if your system has libXinerama).
In general on XINERAMA displays you may need to use the
\fB-xwarppointer\fR option if the mouse pointer misbehaves.
.PP
\fB-xrandr\fR \fI[mode]\fR
.IP
If the display supports the XRANDR (X Resize, Rotate
and Reflection) extension, and you expect XRANDR events
to occur to the display while x11vnc is running, this
options indicates x11vnc should try to respond to
them (as opposed to simply crashing by assuming the
old screen size).  See the 
.IR xrandr (1)
manpage and run
\'xrandr \fB-q'\fR for more info.  [mode] is optional and
described below.
.IP
Since watching for XRANDR events and errors increases
polling overhead, only use this option if XRANDR changes
are expected.  For example on a rotatable screen PDA or
laptop, or using a XRANDR-aware Desktop where you resize
often.  It is best to be viewing with a vncviewer that
supports the NewFBSize encoding, since it knows how to
react to screen size changes.  Otherwise, libvncserver
tries to do so something reasonable for viewers that
cannot do this (portions of the screen may be clipped,
unused, etc).
.IP
"mode" defaults to "resize", which means create a
new, resized, framebuffer and hope all viewers can cope
with the change.  "newfbsize" means first disconnect
all viewers that do not support the NewFBSize VNC
encoding, and then resize the framebuffer.  "exit"
means disconnect all viewer clients, and then terminate
x11vnc.
.PP
\fB-padgeom\fR \fIWxH\fR
.IP
Whenever a new vncviewer connects, the framebuffer is
replaced with a fake, solid black one of geometry WxH.
Shortly afterwards the framebuffer is replaced with the
real one.  This is intended for use with vncviewers
that do not support NewFBSize and one wants to make
sure the initial viewer geometry will be big enough
to handle all subsequent resizes (e.g. under \fB-xrandr,\fR
\fB-remote\fR id:windowid, rescaling, etc.
.PP
\fB-o\fR \fIlogfile\fR
.IP
Write stderr messages to file \fIlogfile\fR instead of
to the terminal.  Same as "\fB-logfile\fR \fIfile\fR".
.PP
\fB-rc\fR \fIfilename\fR
.IP
Use \fIfilename\fR instead of $HOME/.x11vncrc for rc file.
.PP
\fB-norc\fR
.IP
Do not process any .x11vncrc file for options.
.PP
\fB-h,\fR \fB-help\fR
.IP
Print this help text.
.PP
\fB-V,\fR \fB-version\fR
.IP
Print program version (last modification date).
.PP
\fB-q\fR
.IP
Be quiet by printing less informational output to
stderr.  Same as \fB-quiet.\fR
.PP
\fB-bg\fR
.IP
Go into the background after screen setup.  Messages to
stderr are lost unless \fB-o\fR logfile is used.  Something
like this could be useful in a script:
.IP
port=`ssh $host "x11vnc -display :0 -bg" | grep PORT`
.IP
port=`echo "$port" | sed -e 's/PORT=//'`
.IP
port=`expr $port - 5900`
.IP
vncviewer $host:$port
.PP
\fB-modtweak,\fR \fB-nomodtweak\fR
.IP
Option \fB-modtweak\fR automatically tries to adjust the AltGr
and Shift modifiers for differing language keyboards
between client and host.  Otherwise, only a single key
press/release of a Keycode is simulated (i.e. ignoring
the state of the modifiers: this usually works for
identical keyboards).  Also useful in resolving cases
where a Keysym is bound to multiple keys (e.g. "<" + ">"
and "," + "<" keys).  Default: \fB-modtweak\fR
.PP
\fB-xkb\fR
.IP
When in modtweak mode, use the XKEYBOARD extension (if
the X display supports it) to do the modifier tweaking.
This is powerful and should be tried if there are still
keymapping problems when using \fB-modtweak\fR by itself.
.PP
\fB-skip_keycodes\fR \fIstring\fR
.IP
Ignore the comma separated list of decimal keycodes.
Perhaps these are keycodes not on your keyboard but
your X server thinks exist.  Currently only applies
to \fB-xkb\fR mode.  Use this option to help x11vnc in the
reverse problem it tries to solve: Keysym -> Keycode(s)
when ambiguities exist (more than one Keycode per
Keysym).  Run 'xmodmap \fB-pk'\fR to see your keymapping.
E.g. "\fB-skip_keycodes\fR \fI94,114\fR"
.PP
\fB-add_keysyms\fR
.IP
If a Keysym is received from a VNC viewer and
that Keysym does not exist in the X server, then
add the Keysym to the X server's keyboard mapping.
Added Keysyms will be removed when exiting.
.PP
\fB-clear_mods\fR
.IP
At startup and exit clear the modifier keys by sending
KeyRelease for each one. The Lock modifiers are skipped.
Used to clear the state if the display was accidentally
left with any pressed down.
.PP
\fB-clear_keys\fR
.IP
As \fB-clear_mods,\fR except try to release any pressed key.
Note that this option and \fB-clear_mods\fR can interfere
with a person typing at the physical keyboard.
.PP
\fB-remap\fR \fIstring\fR
.IP
Read Keysym remappings from file named \fIstring\fR.
Format is one pair of Keysyms per line (can be name
or hex value) separated by a space.  If no file named
\fIstring\fR exists, it is instead interpreted as this
form: key1-key2,key3-key4,...  See <X11/keysymdef.h>
header file for a list of Keysym names, or use
.IR xev (1).
To map a key to a button click, use the
fake Keysyms "Button1", ..., etc.  E.g. "-remap
Super_R-Button2" (useful for pasting on a laptop)
.PP
\fB-norepeat,\fR \fB-repeat\fR
.IP
Option \fB-norepeat\fR disables X server key auto repeat
when VNC clients are connected.  This works around a
repeating keystrokes bug (triggered by long processing
delays between key down and key up client events:
either from large screen changes or high latency).
Note: your VNC viewer side will likely do autorepeating,
so this is no loss unless someone is simultaneously at
the real X display.  Default: \fB-norepeat\fR
.PP
\fB-nofb\fR
.IP
Ignore video framebuffer: only process keyboard and
pointer.  Intended for use with Win2VNC and x2vnc
dual-monitor setups.
.PP
\fB-nobell\fR
.IP
Do not watch for XBell events. (no beeps will be heard)
Note: XBell monitoring requires the XKEYBOARD extension.
.PP
\fB-nosel\fR
.IP
Do not manage exchange of X selection/cutbuffer between
VNC viewers and the X server.
.PP
\fB-noprimary\fR
.IP
Do not poll the PRIMARY selection for changes to send
back to clients.  (PRIMARY is still set on received
changes, however).
.PP
\fB-cursor\fR \fI[mode],\fR \fB-nocursor\fR
.IP
Sets how the pointer cursor shape (little icon at the
mouse pointer) should be handled.  The "mode" string
is optional and is described below.  The default
is to show some sort of cursor shape(s).  How this
is done depends on the VNC viewer and the X server.
Use \fB-nocursor\fR to disable cursor shapes completely.
.IP
Some VNC viewers support the TightVNC CursorPosUpdates
and CursorShapeUpdates extensions (cuts down on
network traffic by not having to send the cursor image
every time the pointer is moved), in which case these
extensions are used (see \fB-nocursorshape\fR and \fB-nocursorpos\fR
below to disable).  For other viewers the cursor shape
is written directly to the framebuffer every time the
pointer is moved or changed and gets sent along with
the other framebuffer updates.  In this case, there
will be some lag between the vnc viewer pointer and
the remote cursor position.
.IP
If the X display supports retrieving the cursor shape
information from the X server, then the default is
to use that mode.  On Solaris this can be done with
the SUN_OVL extension using \fB-overlay\fR (see also the
\fB-overlay_nomouse\fR option).  A similar overlay scheme
is used on IRIX.  Xorg (e.g. Linux) and recent Solaris
Xsun servers support the XFIXES extension to retrieve
the exact cursor shape from the X server.  If XFIXES
is present it is preferred over Overlay and is used by
default (see \fB-noxfixes\fR below).  This can be disabled
with \fB-nocursor,\fR and also some values of the "mode"
option below.
.IP
The "mode" string can be used to fine-tune the
displaying of cursor shapes.  It can be used the
following ways:
.IP
"\fB-cursor\fR \fIarrow\fR" - just show the standard arrow
nothing more or nothing less.
.IP
"\fB-cursor\fR \fInone\fR" - same as "\fB-nocursor\fR"
.IP
"\fB-cursor\fR \fIX\fR" - when the cursor appears to be on the
root window, draw the familiar X shape.  Some desktops
such as GNOME cover up the root window completely,
and so this will not work, try "X1", etc, to try to
shift the tree depth.  On high latency links or slow
machines there will be a time lag between expected and
the actual cursor shape.
.IP
"\fB-cursor\fR \fIsome\fR" - like "X" but use additional
heuristics to try to guess if the window should have
a windowmanager-like resizer cursor or a text input
I-beam cursor.  This is a complete hack, but may be
useful in some situations because it provides a little
more feedback about the cursor shape.
.IP
"\fB-cursor\fR \fImost\fR" - try to show as many cursors as
possible.  Often this will only be the same as "some"
unless the display has overlay visuals or XFIXES
extensions available.  On Solaris and IRIX if XFIXES
is not available, \fB-overlay\fR mode will be attempted.
.PP
\fB-noxfixes\fR
.IP
Do not use the XFIXES extension to draw the exact cursor
shape even if it is available.
.PP
\fB-nocursorshape\fR
.IP
Do not use the TightVNC CursorShapeUpdates extension
even if clients support it.  See \fB-cursor\fR above.
.PP
\fB-cursorpos,\fR \fB-nocursorpos\fR
.IP
Option \fB-cursorpos\fR enables sending the X cursor position
back to all vnc clients that support the TightVNC
CursorPosUpdates extension.  Other clients will be able
to see the pointer motions. Default: \fB-cursorpos\fR
.PP
\fB-xwarppointer\fR
.IP
Move the pointer with 
.IR XWarpPointer (3X)
instead of
the XTEST extension.  Use this as a workaround
if the pointer motion behaves incorrectly, e.g.
on touchscreens or other non-standard setups.
Also sometimes needed on XINERAMA displays.
.PP
\fB-buttonmap\fR \fIstring\fR
.IP
String to remap mouse buttons.  Format: IJK-LMN, this
maps buttons I -> L, etc., e.g.  \fB-buttonmap\fR 13-31
.IP
Button presses can also be mapped to keystrokes: replace
a button digit on the right of the dash with :<sym>:
or :<sym1>+<sym2>: etc. for multiple keys. For example,
if the viewing machine has a mouse-wheel (buttons 4 5)
but the x11vnc side does not, these will do scrolls:
.IP
\fB-buttonmap\fR 12345-123:Prior::Next:
.IP
\fB-buttonmap\fR 12345-123:Up+Up+Up::Down+Down+Down:
.IP
See <X11/keysymdef.h> header file for a list of Keysyms,
or use the 
.IR xev (1)
program.  Note: mapping of button
clicks to Keysyms may not work if \fB-modtweak\fR or \fB-xkb\fR is
needed for the Keysym.
.IP
If you include a modifier like "Shift_L" the
modifier's up/down state is toggled, e.g. to send
"The" use :Shift_L+t+Shift_L+h+e: (the 1st one is
shift down and the 2nd one is shift up). (note: the
initial state of the modifier is ignored and not reset)
To include button events use "Button1", ... etc.
.PP
\fB-nodragging\fR
.IP
Do not update the display during mouse dragging events
(mouse motion with a button held down).  Greatly
improves response on slow setups, but you lose all
visual feedback for drags, text selection, and some
menu traversals.
.PP
\fB-pointer_mode\fR \fIn\fR
.IP
Various pointer update schemes.  The problem is pointer
motion can cause rapid changes on the screen, e.g. a
window drag.  Neither x11vnc nor the bandwidth to the
vncviewers can keep up these rapid screen changes:
everything bogs down when dragging or scrolling.
Note that most video h/w is optimized for writing, not
reading (a 50X rate difference is possible) and x11vnc
is reading all the time.  So a scheme has to be used to
"eat" much of that pointer input before re-polling the
screen. n can be 1 to 4.  n=1 was the original scheme
used to about Jan 2004.  n=2 is an improved scheme.
n=3 is basically a dynamic \fB-nodragging\fR mode: it detects
if the mouse drag motion has paused and refreshes
the display.  n=4 is TBD.  The default n is 2.
.PP
\fB-input_skip\fR \fIn\fR
.IP
For the pointer handling when non-threaded: try to
read n user input events before scanning display. n < 0
means to act as though there is always user input.
Default: 10
.PP
\fB-debug_pointer\fR
.IP
Print debugging output for every pointer event.
.PP
\fB-debug_keyboard\fR
.IP
Print debugging output for every keyboard event.
.PP
Same as \fB-dp\fR and \fB-dk,\fR respectively.  Use multiple
times for more output.
.PP
\fB-defer\fR \fItime\fR
.IP
Time in ms to wait for updates before sending to client
(deferUpdateTime)  Default: 30
.PP
\fB-wait\fR \fItime\fR
.IP
Time in ms to pause between screen polls.  Used to cut
down on load.  Default: 30
.PP
\fB-nap\fR
.IP
Monitor activity and if low take longer naps between
polls to really cut down load when idle.  Default: off
.PP
\fB-sb\fR \fItime\fR
.IP
Time in seconds after NO activity (e.g. screen blank)
to really throttle down the screen polls (i.e. sleep
for about 1.5 secs). Use 0 to disable.  Default: 60
.PP
\fB-sigpipe\fR \fIstring\fR
.IP
Broken pipe (SIGPIPE) handling.  \fIstring\fR can be
"ignore" or "exit".  For "ignore" libvncserver
will handle the abrupt loss of a client and continue,
for "exit" x11vnc will cleanup and exit at the 1st
broken connection.  Default: "ignore".
.PP
\fB-threads,\fR \fB-nothreads\fR
.IP
Whether or not to use the threaded libvncserver
algorithm [rfbRunEventLoop] if libpthread is available
Default: \fB-nothreads\fR
.PP
\fB-fs\fR \fIf\fR
.IP
If the fraction of changed tiles in a poll is greater
than f, the whole screen is updated.  Default: 0.75
.PP
\fB-gaps\fR \fIn\fR
.IP
Heuristic to fill in gaps in rows or cols of n or
less tiles.  Used to improve text paging.  Default: 4
.PP
\fB-grow\fR \fIn\fR
.IP
Heuristic to grow islands of changed tiles n or wider
by checking the tile near the boundary.  Default: 3
.PP
\fB-fuzz\fR \fIn\fR
.IP
Tolerance in pixels to mark a tiles edges as changed.
Default: 2
.PP
\fB-gui\fR \fI[gui-opts]\fR
.IP
Start up a simple tcl/tk gui based on the the remote
control options \fB-remote/-query\fR described below.
Requires the "wish" program to be installed on the
machine.  "gui-opts" is not required: the default is
to start up both the gui and x11vnc with the gui showing
up on the X display in the environment variable DISPLAY.
.IP
"gui-opts" can be a comma separated list of items.
Currently there are only two types of items: 1) a gui
mode and 2) the X display the gui should display on.
The gui mode can be "start", "conn", or "wait"
"start" is the default mode above and is not required.
"conn" means do not automatically start up x11vnc,
but instead just try to connect to an existing x11vnc
process.  "wait" means just start the gui and nothing
else (you will later instruct the gui to start x11vnc
or connect to an existing one.)
.IP
Note the possible confusion regarding the potentially
two different X displays: x11vnc polls one, but you
may want the gui to appear on another.  For example, if
you ssh in and x11vnc is not running yet you may want
the gui to come back to you via your ssh redirected X
display (e.g. localhost:10).
.IP
Examples: "x11vnc \fB-gui",\fR "x11vnc \fB-gui\fR localhost:10",
"x11vnc \fB-gui\fR :10", "x11vnc \fB-gui\fR wait,:10",
"x11vnc \fB-gui\fR <x11vnc-opts...>"
.IP
If you do not specify a gui X display in "gui-opts"
then the DISPLAY environment variable and \fB-display\fR
option are tried (in that order).  Regarding the x11vnc
X display the gui will try to connect to, it first
tries \fB-display\fR and then DISPLAY.  For example, "x11vnc
\fB-display\fR :0 \fB-gui\fR otherhost:0", will remote control an
x11vnc polling :0 and display the gui on otherhost:0
.IP
If you do not intend to start x11vnc from the gui
(i.e. just remote control an existing one), then the
gui process can run on a different machine from the
x11vnc server as long as X permissions, etc. permit
communication between the two.
.PP
\fB-remote\fR \fIcommand\fR
.IP
Remotely control some aspects of an already running
x11vnc server.  "\fB-R\fR" and "\fB-r\fR" are aliases for
"\fB-remote\fR".  After the remote control command is
sent to the running server the 'x11vnc \fB-remote\fR ...'
command exits.  You can often use the \fB-query\fR command
(see below) to see if the x11vnc server processed your
\fB-remote\fR command.
.IP
The default communication channel is that of X
properties (specifically VNC_CONNECT), and so this
command must be run with correct settings for DISPLAY
and possibly XAUTHORITY to connect to the X server
and set the property.  Alternatively, use the \fB-display\fR
and \fB-auth\fR options to set them to the correct values.
The running server cannot use the \fB-novncconnect\fR option
because that disables the communication channel.
See below for alternate channels.
.IP
For example: 'x11vnc \fB-remote\fR stop' (which is the same as
\'x11vnc \fB-R\fR stop') will close down the x11vnc server.
\'x11vnc \fB-R\fR shared' will enable shared connections, and
\'x11vnc \fB-R\fR scale:3/4' will rescale the desktop.
.IP
Note: the more drastic the change induced by the \fB-remote\fR
command, the bigger the chance for bugs or crashes.
Please report reproducible bugs.
.IP
.IP
The following \fB-remote/-R\fR commands are supported:
.IP
stop            terminate the server, same as "quit"
                "exit" or "shutdown"
.IP
ping            see if the x11vnc server responds.
                Return is: ans=ping:<xdisplay>
.IP
blacken         try to push a black fb update to all
                clients (due to timings a client
                could miss it). Same as "zero", also
                "zero:x1,y1,x2,y2" for a rectangle.
.IP
refresh         send the entire fb to all clients.
.IP
reset           recreate the fb, polling memory, etc.
.IP
id:windowid     set \fB-id\fR window to "windowid". empty
                or "root" to go back to root window
.IP
sid:windowid    set \fB-sid\fR window to "windowid"
.IP
flashcmap       enable  \fB-flashcmap\fR mode.
.IP
noflashcmap     disable \fB-flashcmap\fR mode.
.IP
notruecolor     enable  \fB-notruecolor\fR mode.
.IP
truecolor       disable \fB-notruecolor\fR mode.
.IP
overlay         enable  \fB-overlay\fR mode (if applicable).
.IP
nooverlay       disable \fB-overlay\fR mode.
.IP
overlay_cursor  in \fB-overlay\fR mode, enable cursor drawing.
.IP
overlay_nocursor disable cursor drawing. same as
                nooverlay_cursor.
.IP
visual:vis      set \fB-visual\fR to "vis"
.IP
scale:frac      set \fB-scale\fR to "frac"
.IP
viewonly        enable  \fB-viewonly\fR mode.
.IP
noviewonly      disable \fB-viewonly\fR mode.
.IP
shared          enable  \fB-shared\fR mode.
.IP
noshared        disable \fB-shared\fR mode.
.IP
forever         enable  \fB-forever\fR mode.
.IP
noforever       disable \fB-forever\fR mode.
.IP
deny            deny any new connections, same as "lock"
.IP
nodeny          allow new connections, same as "unlock"
.IP
connect:host    do reverse connection to host, "host"
                may be a comma separated list of hosts
                or host:ports.  See \fB-connect.\fR
.IP
disconnect:host disconnect any clients from "host"
                same as "close:host".  Use host
                "all" to close all current clients.
                If you know the client internal hex ID,
                e.g. 0x3 (returned by \fB-query\fR clients and
                RFB_CLIENT_ID), you can use that too.
.IP
allowonce:host  For the next connection only, allow
                connection from "host".
.IP
allow:hostlist  set \fB-allow\fR list to (comma separated)
                "hostlist". See \fB-allow\fR and \fB-localhost.\fR
                Do not use with \fB-allow\fR /path/to/file
                Use "+host" to add a single host, and
                use "\fB-host\fR" to delete a single host
.IP
localhost       enable  \fB-localhost\fR mode
.IP
nolocalhost     disable \fB-localhost\fR mode
.IP
accept:cmd      set \fB-accept\fR "cmd" (empty to disable).
.IP
gone:cmd        set \fB-gone\fR "cmd" (empty to disable).
.IP
noshm           enable  \fB-noshm\fR mode.
.IP
shm             disable \fB-noshm\fR mode (i.e. use shm).
.IP
flipbyteorder   enable \fB-flipbyteorder\fR mode, you may need
                to set noshm for this to do something.
.IP
noflipbyteorder disable \fB-flipbyteorder\fR mode.
.IP
onetile         enable  \fB-onetile\fR mode. (you may need to
                set shm for this to do something)
.IP
noonetile       disable \fB-onetile\fR mode.
.IP
blackout:str    set \fB-blackout\fR "str" (empty to disable).
                See \fB-blackout\fR for the form of "str"
                (basically: WxH+X+Y,...)
                Use "+WxH+X+Y" to append a single
                rectangle use "-WxH+X+Y" to delete one
.IP
xinerama        enable  \fB-xinerama\fR mode. (if applicable)
.IP
noxinerama      disable \fB-xinerama\fR mode.
.IP
xrandr          enable  \fB-xrandr\fR mode. (if applicable)
.IP
noxrandr        disable \fB-xrandr\fR mode.
.IP
xrandr_mode:mode set the \fB-xrandr\fR mode to "mode".
.IP
padgeom:WxH     set \fB-padgeom\fR to WxH (empty to disable)
                If WxH is "force" or "do" the padded
                geometry fb is immediately applied.
.IP
quiet           enable  \fB-quiet\fR mode.
.IP
noquiet         disable \fB-quiet\fR mode.
.IP
modtweak        enable  \fB-modtweak\fR mode.
.IP
nomodtweak      enable  \fB-nomodtweak\fR mode.
.IP
xkb             enable  \fB-xkb\fR modtweak mode.
.IP
noxkb           disable \fB-xkb\fR modtweak mode.
.IP
skip_keycodes:str enable \fB-xkb\fR \fB-skip_keycodes\fR "str".
.IP
add_keysyms     enable \fB-add_keysyms\fR mode.
.IP
noadd_keysyms   stop adding keysyms. those added will
                still be removed at exit.
.IP
clear_mods      enable  \fB-clear_mods\fR mode and clear them.
.IP
noclear_mods    disable \fB-clear_mods\fR mode.
.IP
clear_keys      enable  \fB-clear_keys\fR mode and clear them.
.IP
noclear_keys    disable \fB-clear_keys\fR mode.
.IP
remap:str       set \fB-remap\fR "str" (empty to disable).
                See \fB-remap\fR for the form of "str"
                (basically: key1-key2,key3-key4,...)
                Use "+key1-key2" to append a single
                keymapping, use "-key1-key2" to delete.
.IP
norepeat        enable  \fB-norepeat\fR mode.
.IP
repeat          disable \fB-norepeat\fR mode.
.IP
bell            enable  bell (if supported).
.IP
nobell          disable bell.
.IP
sel             disable \fB-nosel\fR mode.
.IP
nosel           enable  \fB-nosel\fR mode.
.IP
primary         disable \fB-noprimary\fR mode.
.IP
noprimary       enable  \fB-noprimary\fR mode.
.IP
cursor:mode     enable  \fB-cursor\fR "mode".
.IP
show_cursor     enable  showing a cursor.
.IP
noshow_cursor   disable showing a cursor. (same as
                "nocursor")
.IP
xfixes          enable  xfixes cursor shape mode.
.IP
noxfixes        disable xfixes cursor shape mode.
.IP
cursorshape     disable \fB-nocursorshape\fR mode.
.IP
nocursorshape   enable  \fB-nocursorshape\fR mode.
.IP
cursorpos       disable \fB-nocursorpos\fR mode.
.IP
nocursorpos     enable  \fB-nocursorpos\fR mode.
.IP
xwarp           enable  \fB-xwarppointer\fR mode.
.IP
noxwarp         disable \fB-xwarppointer\fR mode.
.IP
buttonmap:str   set \fB-buttonmap\fR "str", empty to disable
.IP
dragging        disable \fB-nodragging\fR mode.
.IP
nodragging      enable  \fB-nodragging\fR mode.
.IP
pointer_mode n  set \fB-pointer_mode\fR to n.
.IP
input_skip n    set \fB-input_skip\fR to n.
.IP
debug_pointer   enable  \fB-debug_pointer,\fR same as "dp"
.IP
nodebug_pointer disable \fB-debug_pointer,\fR same as "nodp"
.IP
debug_keyboard   enable  \fB-debug_keyboard,\fR same as "dk"
.IP
nodebug_keyboard disable \fB-debug_keyboard,\fR same as "nodk"
.IP
defer:n         set \fB-defer\fR to n ms,same as deferupdate:n
.IP
wait:n          set \fB-wait\fR to n ms.
.IP
nap             enable  \fB-nap\fR mode.
.IP
nonap           disable \fB-nap\fR mode.
.IP
sb:n            set \fB-sb\fR to n s, same as screen_blank:n
.IP
fs:frac         set \fB-fs\fR fraction to "frac", e.g. 0.5
.IP
gaps:n          set \fB-gaps\fR to n.
.IP
grow:n          set \fB-grow\fR to n.
.IP
fuzz:n          set \fB-fuzz\fR to n.
.IP
progressive:n   set libvncserver \fB-progressive\fR slice
                height parameter to n.
.IP
file:name       run \fB-remote\fR commands from file "name",
                one command per line,blank and # skipped
.IP
noremote        disable the \fB-remote\fR command processing,
                it cannot be turned back on.
.IP
.IP
The 
.IR vncconnect (1)
command from standard VNC
.IP
distributions may also be used if string is prefixed
.IP
with "cmd=" E.g. 'vncconnect cmd=stop'.  Under some
.IP
circumstances 
.IR xprop (1)
can used if it supports \fB-set\fR
.IP
(see the FAQ).
.IP
.IP
If "\fB-connect\fR \fI/path/to/file\fR" has been supplied to the
.IP
running x11vnc server then that file can be used as a
.IP
communication channel (this is the only way to remote
.IP
control one of many x11vnc's polling the same X display)
.IP
Simply run: 'x11vnc \fB-connect\fR /path/to/file \fB-remote\fR ...'
.IP
or you can directly write to the file via something
.IP
like: "echo cmd=stop > /path/to/file", etc.
.PP
\fB-query\fR \fIvariable\fR
.IP
Like \fB-remote,\fR except just query the value of
\fIvariable\fR.  "\fB-Q\fR" is an alias for "\fB-query\fR".
Multiple queries can be done by separating variables
by commas, e.g. \fB-query\fR var1,var2. The results come
back in the form ans=var1:value1,ans=var2:value2,...
to the standard output.  If a variable is read-only,
it comes back with prefix "aro=" instead of "ans=".
.IP
Some \fB-remote\fR commands are pure actions that do not make
sense as variables, e.g. "stop" or "disconnect",
in these cases the value returned is "N/A".  To direct
a query straight to the VNC_CONNECT property or connect
file use "qry=..." instead of "cmd=..."
.IP
Here is the current list of "variables" that can
be supplied to the \fB-query\fR command. This includes the
"N/A" ones that return no useful info.  For variables
names that do not correspond to an x11vnc option or
remote command, we hope the name makes it obvious what
the returned value corresponds to (hint: the ext_*
variables correspond to the presence of X extensions):
.IP
ans= stop quit exit shutdown ping blacken zero refresh
reset close disconnect id sid flashcmap noflashcmap
truecolor notruecolor overlay nooverlay overlay_cursor
overlay_yescursor nooverlay_cursor overlay_nocursor
visual scale viewonly noviewonly shared noshared
forever noforever once deny lock nodeny unlock connect
allowonce allow localhost nolocalhost accept gone shm
noshm flipbyteorder noflipbyteorder onetile noonetile
blackout xinerama noxinerama xrandr noxrandr xrandr_mode
padgeom quiet q noquiet modtweak nomodtweak xkb noxkb
skip_keycodes add_keysyms noadd_keysyms clear_mods
noclear_mods clear_keys noclear_keys remap repeat
norepeat bell nobell sel nosel primary noprimary
cursorshape nocursorshape cursorpos nocursorpos cursor
show_cursor noshow_cursor nocursor xfixes noxfixes xwarp
xwarppointer noxwarp noxwarppointer buttonmap dragging
nodragging pointer_mode input_skip debug_pointer dp
nodebug_pointer nodp debug_keyboard dk nodebug_keyboard
nodk deferupdate defer wait nap nonap sb screen_blank
fs gaps grow fuzz progressive noremote
.IP
aro=  display vncdisplay desktopname desktop auth
rootshift scale_str scaled_x scaled_y scale_numer
scale_denom scale_fac scaling_noblend scaling_nomult4
scaling_pad scaling_interpolate inetd safer unsafe
passwdfile using_shm logfile o rc norc h help V version
lastmod bg nofb sigpipe threads clients client_count
pid ext_xtest ext_xkb ext_xshm ext_xinerama ext_overlay
ext_xfixes ext_xdamage ext_xrandr rootwin num_buttons
button_mask mouse_x mouse_y bpp depth indexed_color
dpy_x dpy_y rfbport rfbwait rfbauth passwd alwaysshared
dontdisconnect httpdir enablehttpproxy
.PP
\fB-noremote\fR
.IP
Do not process any remote control commands or queries.
.IP
A note about security wrt remote control commands.
If someone can connect to the X display and change the
property VNC_CONNECT, then they can remotely control
x11vnc.  Normally access to the X display is protected.
Note that if they can modify VNC_CONNECT, they could
also run their own x11vnc and have complete control
of the desktop.  If the  "\fB-connect\fR \fI/path/to/file\fR"
channel is being used, obviously anyone who can write
to /path/to/file can remotely control x11vnc.  So be
sure to protect the X display and that file's write
permissions.
.PP
\fB-unsafe\fR
.IP
If x11vnc is running as root (e.g. inetd or Xsetup for
a display manager) a few remote commands are disabled
(currently: id:pick, accept:<cmd>, and gone:<cmd>)
because they are associated with running external
programs.  If you specify \fB-unsafe,\fR then these remote
control commands are allowed when running as root.
When running as non-root all commands are allowed.
See \fB-safer\fR below.
.PP
\fB-safer\fR
.IP
Even if not running as root, disable the above unsafe
remote control commands.
.PP
\fB-deny_all\fR
.IP
For use with \fB-remote\fR nodeny: start out denying all
incoming clients until "\fB-remote\fR \fInodeny\fR" is used to
let them in.
.PP
These options are passed to libvncserver:
.PP
\fB-rfbport\fR \fIport\fR
.IP
TCP port for RFB protocol
.PP
\fB-rfbwait\fR \fItime\fR
.IP
max time in ms to wait for RFB client
.PP
\fB-rfbauth\fR \fIpasswd-file\fR
.IP
use authentication on RFB protocol
(use 'storepasswd' to create a password file)
.PP
\fB-passwd\fR \fIplain-password\fR
.IP
use authentication
(use plain-password as password, USE AT YOUR RISK)
.PP
\fB-deferupdate\fR \fItime\fR
.IP
time in ms to defer updates (default 40)
.PP
\fB-desktop\fR \fIname\fR
.IP
VNC desktop name (default "LibVNCServer")
.PP
\fB-alwaysshared\fR
.IP
always treat new clients as shared
.PP
\fB-nevershared\fR
.IP
never treat new clients as shared
.PP
\fB-dontdisconnect\fR
.IP
don't disconnect existing clients when a new non-shared
connection comes in (refuse new connection instead)
.PP
\fB-httpdir\fR \fIdir-path\fR
.IP
enable http server using dir-path home
.PP
\fB-httpport\fR \fIportnum\fR
.IP
use portnum for http connection
.PP
\fB-enablehttpproxy\fR
.IP
enable http proxy support
.PP
\fB-progressive\fR \fIheight\fR
.IP
enable progressive updating for slow links
.SH "FILES"
.IR $HOME/.x11vncrc ,
.IR $HOME/.Xauthority
.SH "ENVIRONMENT"
.IR DISPLAY ,
.IR XAUTHORITY ,
.IR HOME
.PP
The following are set for the auxiliary commands
run by \fB-accept\fR and \fB-gone\fR:
.PP
.IR RFB_CLIENT_IP ,
.IR RFB_CLIENT_PORT ,
.IR RFB_SERVER_IP ,
.IR RFB_SERVER_PORT ,
.IR RFB_X11VNC_PID ,
.IR RFB_CLIENT_ID ,
.IR RFB_CLIENT_COUNT ,
.IR RFB_MODE
.SH "SEE ALSO"
.IR vncviewer (1),
.IR vncpasswd (1),
.IR vncconnect (1),
.IR vncserver (1),
.IR Xvnc (1),
.IR inetd (1),
.IR xev (1),
.IR xmodmap (1),
.IR Xserver (1),
.IR xauth (1),
.IR xhost (1),
.IR Xsecurity (7),
.IR xmessage (1),
.IR ipcrm (1),
.IR http://www.tightvnc.com ,
.IR http://www.realvnc.com ,
.IR http://www.karlrunge.com/x11vnc/ ,
.IR http://www.karlrunge.com/x11vnc/#faq
.SH AUTHORS
x11vnc was written by Karl J. Runge <runge@karlrunge.com>,
it is part of the LibVNCServer project <http://sf.net/projects/libvncserver>.
This manual page is based one the one written by Ludovic Drolez
<ldrolez@debian.org>, for the Debian project (both may be used by others).