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x11vnc (1)
>> x11vnc (1) ( Linux man: Команды и прикладные программы пользовательского уровня )
NAME
x11vnc - allow VNC connections to real X11 displays
version: 0.8.2, lastmod: 2006-07-12
SYNOPSIS
x11vnc
[OPTION]...
DESCRIPTION
Typical usage is:
Run this command in a shell on the remote machine "far-host"
with X session you wish to view:
x11vnc -display :0
Then run this in another window on the machine you are sitting at:
vncviewer far-host:0
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".
By default x11vnc will not allow the screen to be shared and it will exit
as soon as the client disconnects. See -shared and -forever below to override
these protections. See the FAQ for details how to tunnel the VNC connection
through an encrypted channel such as
ssh(1).
In brief:
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 -norc.
For each option name, the leading character "-" is not required. E.g. a
line that is either "forever" or "-forever" may be used and are equivalent.
Likewise "wait 100" or "-wait100" are acceptable and equivalent lines.
The "#" character comments out to the end of the line in the usual way
(backslash it for a literal). 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).
OPTIONS
-displaydisp
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 disp. See the description
below of the "-displayWAIT:..." extensions.
-authfile
Set the X authority file to be file, equivalent to
setting the XAUTHORITY environment variable to file
before startup. Same as -xauth file. See
Xsecurity(7)
,
xauth(1)
man pages for more info.
-idwindowid
Show the window corresponding to windowid 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 -xrandr mechanism is used to track resizes. Use
xwininfo(1)
to get the window id, or use "-idpick"
to have x11vnc run
xwininfo(1)
for you and extract
the id. The -id option is useful for exporting very
simple applications (e.g. the current view on a webcam).
-sidwindowid
As -id, 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.
-clipWxH+X+Y
Only show the sub-region of the full display that
corresponds to the rectangle with size WxH and offset
+X+Y. The VNC display has size WxH (i.e. smaller than
the full display). This also works for -id/-sid mode
where the offset is relative to the upper left corner
of the selected window.
-flashcmap
In 8bpp indexed color, let the installed colormap flash
as the pointer moves from window to window (slow).
Also try the -8to24 option to avoid flash altogether.
-shiftcmapn
Rare problem, but some 8bpp displays use less than 256
colorcells (e.g. 16-color grayscale, perhaps the other
bits are used for double buffering) *and* also need to
shift the pixels values away from 0, .., ncells. n
indicates the shift to be applied to the pixel values.
To see the pixel values set DEBUG_CMAP=1 to print out
a colormap histogram. Example: -shiftcmap 240
-notruecolor
For 8bpp displays, force indexed color (i.e. a colormap)
even if it looks like 8bpp TrueColor (rare problem).
-visualn
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
xdpyinfo(1)
for the values. One may
also use "TrueColor", etc. see <X11/X.h> for a list.
If the string ends in ":m" then for better or for
worse the visual depth is forced to be m.
-overlay
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).
Currently -overlay only works on Solaris via
XReadScreen(3X11)
and IRIX using
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 "-su" argument to Xsun (in
/etc/dt/config/Xservers).
Use -overlay 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 incorrect
in x11vnc unless -overlay is used. Another use of
-overlay is to enable showing the exact mouse cursor
shape (details below).
Under -overlay, performance will be somewhat slower
due to the extra image transformations required.
For optimal performance do not use -overlay, but rather
configure the X server so that the default visual is
depth 24 TrueColor and try to have all apps use that
visual (e.g. some apps have -use24 or -visual options).
-overlay_nocursor
Sets -overlay, but does not try to draw the exact mouse
cursor shape using the overlay mechanism.
-8to24[opts]
Try this option if -overlay is not supported on your
OS, and you have a legacy 8bpp app that you want to
view on a multi-depth display with default depth 24
(and is 32 bpp) OR have a default depth 8 display with
depth 24 overlay windows for some apps. This option
may not work on all X servers and hardware (tested
on XFree86/Xorg mga driver and Xsun). The "opts"
string is not required and is described below.
This mode enables a hack where x11vnc monitors windows
within 3 levels from the root window. If it finds
any that are 8bpp it extracts the indexed color
pixel values using XGetImage() and then applies a
transformation using the colormap(s) to create TrueColor
RGB values that it in turn inserts into bits 1-24 of
the framebuffer. This creates a depth 24 "view"
of the display that is then exported via VNC.
Conversely, for default depth 8 displays, the depth
24 regions are read by XGetImage() and everything is
transformed and inserted into a depth 24 TrueColor
framebuffer.
Note that even if there are *no* depth 24 visuals or
windows (i.e. pure 8bpp), this mode is potentially
an improvement over -flashcmap because it avoids the
flashing and shows each window in the correct color.
This method appear to work, but may still have bugs
and it does hog resources. If there are multiple 8bpp
windows using different colormaps, one may have to
iconify all but one for the colors to be correct.
There may be painting errors for clipping and switching
between windows of depths 8 and 24. Heuristics are
applied to try to minimize the painting errors. One can
also press 3 Alt_L's in a row to refresh the screen
if the error does not repair itself. Also the option
-fixscreen 8=3.0 or -fixscreen V=3.0 may be used to
periodically refresh the screen at the cost of bandwidth
(every 3 sec for this example).
The [opts] string can contain the following settings.
Multiple settings are separated by commas.
For for some X servers with default depth 24 a
speedup may be achieved via the option "nogetimage".
This enables a scheme were XGetImage() is not used
to retrieve the 8bpp data. Instead, it assumes that
the 8bpp data is in bits 25-32 of the 32bit X pixels.
There is no requirement that the X server should put
the data there for our poll requests, but some do and
so the extra steps to retrieve it can be skipped.
Tested with mga driver with XFree86/Xorg. For the
default depth 8 case this option is ignored.
To adjust how often XGetImage() is used to poll the
non-default visual regions for changes, use the option
"poll=t" where "t" is a floating point time.
(default: 0.05)
Setting the option "level2" will limit the search
for non-default visual windows to two levels from the
root window. Do this on slow machines where you know
the window manager only imposes one extra window between
the app window and the root window.
Also for very slow machines use "cachewin=t"
where t is a floating point amount of time to cache
XGetWindowAttributes results. E.g. cachewin=5.0.
This may lead to the windows being unnoticed for this
amount of time when deiconifying, painting errors, etc.
While testing on a very old SS20 these options gave
tolerable response: -8to24 poll=0.2,cachewin=5.0. For
this machine -overlay is supported and gives better
response.
Debugging for this mode can be enabled by setting
"dbg=1", "dbg=2", or "dbg=3".
-24to32
Very rare problem: if the framebuffer (X display
or -rawfb) is 24bpp instead of the usual 32bpp, then
dynamically transform the pixels to 32bpp. This will be
slower, but can be used to work around problems where
VNC viewers cannot handle 24bpp (e.g. "main: setPF:
not 8, 16 or 32 bpp?"). See the FAQ for more info.
In the case of -rawfb mode, the pixels are directly
modified by inserting a 0 byte to pad them out to 32bpp.
For X displays, a kludge is done that is equivalent to
"-noshm-visual TrueColor:32". (If better performance
is needed for the latter, feel free to ask).
-scalefraction
Scale the framebuffer by factor fraction. Values
less than 1 shrink the fb, larger ones expand it. Note:
image may not be sharp and response may be slower.
If fraction 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. -scale 2/3
Scaling Options: can be added after fraction via
":", to supply multiple ":" options use commas.
If you just want a quick, rough scaling without
blending, append ":nb" to fraction (e.g. -scale
1/3:nb). No blending is the default for 8bpp indexed
color, to force blending for this case use ":fb".
To disable -scrollcopyrect and -wirecopyrect under
-scale use ":nocr". If you need to to enable them use
":cr" or specify them explicitly on the command line.
If a slow link is detected, ":nocr" may be applied
automatically. Default: :cr
More esoteric options: for compatibility with vncviewers
the scaled width is adjusted to be a multiple of 4:
to disable this use ":n4". ":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).
-scale_cursorfrac
By default if -scale is supplied the cursor shape is
scaled by the same factor. Depending on your usage,
you may want to scale the cursor independently of the
screen or not at all. If you specify -scale_cursor
the cursor will be scaled by that factor. When using
-scale mode to keep the cursor at its "natural" size
use "-scale_cursor1". Most of the ":" scaling
options apply here as well.
-viewonly
All VNC clients can only watch (default off).
-shared
VNC display is shared, i.e. more than one viewer can
connect at the same time (default off).
-once
Exit after the first successfully connected viewer
disconnects, opposite of -forever. This is the Default.
-forever
Keep listening for more connections rather than exiting
as soon as the first client(s) disconnect. Same as -many
-loop
Create an outer loop restarting the x11vnc process
whenever it terminates. -bg and -inetd are ignored in
this mode. Useful for continuing even if the X server
terminates and restarts (you will need permission to
reconnect of course). Use, e.g., -loop100 to sleep
100 millisecs between restarts, etc. Default is 2000ms
(i.e. 2 secs) Use, e.g. -loop300,5 to sleep 300 ms
and only loop 5 times.
-timeoutn
Exit unless a client connects within the first n seconds
after startup.
-inetd
Launched by
inetd(8):
stdio instead of listening socket.
Note: if you are not redirecting stderr to a log file
(via shell 2> or -o option) you MUST also specify the -q
option, otherwise the stderr goes to the viewer which
will cause it to abort. Specifying both -inetd and -q
and no -o will automatically close the stderr.
-nofilexfer
Disable the TightVNC file transfer extension. (same as
-disablefiletransfer). Note that when the -viewonly
option is supplied all file transfers are disabled.
Also clients that log in viewonly cannot transfer files.
However, if the remote control mechanism is used to
change the global or per-client viewonly state the
filetransfer permissions will NOT change.
Note, to *enable* UltraVNC filetransfer (currently
disabled by default, this may change...) and to get it
to work you probably need to supply these libvncserver
options: "-rfbversion3.6 -permitfiletransfer"
-http
Instead of using -httpdir (see below) to specify
where the Java vncviewer applet is, have x11vnc try
to *guess* where the directory is by looking relative
to the program location and in standard locations
(/usr/local/share/x11vnc/classes, etc). Under -ssl or
-stunnel the ssl classes subdirectory is sought.
-connectstring
For use with "vncviewer -listen" reverse connections.
If string 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.
Note that unlike most vnc servers, x11vnc will require a
password for reverse as well as for forward connections.
(provided password auth has been enabled, -rfbauth, etc)
If you do not want to require a password for reverse
connections set X11VNC_REVERSE_CONNECTION_NO_AUTH=1 in
your environment before starting x11vnc.
If string 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.
Be careful for this usage mode if x11vnc is running as
root (e.g. via
gdm(1)
, etc).
-vncconnect,-novncconnect
Monitor the VNC_CONNECT X property set by the standard
VNC program
vncconnect(1).
When the property is
set to "host" or "host:port" establish a reverse
connection. Using
xprop(1)
instead of vncconnect may
work (see the FAQ). The -remote control mechanism uses
X11VNC_REMOTE channel, and this option disables/enables
it as well. Default: -vncconnect
-allowhost1[,host2..]
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.
-localhost
Basically the same as "-allow127.0.0.1".
Note: if you want to restrict which network interface
x11vnc listens on, see the -listen option below.
E.g. "-listenlocalhost" or "-listen192.168.3.21".
As a special case, the option "-localhost" implies
"-listenlocalhost".
A rare case, but for non-localhost -listen usage, if
you use the remote control mechanism (-R) to change
the -listen interface you may need to manually adjust
the -allow list (and vice versa) to avoid situations
where no connections (or too many) are allowed.
-nolookup
Do not use gethostbyname() or gethostbyaddr() to look up
host names or IP numbers. Use this if name resolution
is incorrectly set up and leads to long pauses as name
lookups time out, etc.
-inputstring
Fine tuning of allowed user input. If string does
not contain a comma "," the tuning applies only to
normal clients. Otherwise the part before "," is for
normal clients and the part after for view-only clients.
"K" is for Keystroke input, "M" for Mouse-motion
input, "B" for Button-click input, and "C" is for
Clipboard input. Their presence in the string enables
that type of input. E.g. "-inputM" means normal
users can only move the mouse and "-inputKMBC,M"
lets normal users do anything and enables view-only
users to move the mouse. This option is ignored when
a global -viewonly is in effect (all input is discarded
in that case).
-grabkbd
When VNC viewers are connected, attempt to the grab
the keyboard so a (non-malicious) user sitting at the
physical display is not able to enter keystrokes.
This method uses
XGrabKeyboard(3X11)
and so it is
not secure and does not rule out the person at the
physical display injecting keystrokes by flooding the
server with them, grabbing the keyboard himself, etc.
Some degree of cooperation from the person at the
display is assumed. This is intended for remote
help-desk or educational usage modes.
-grabptr
As -grabkbd, but for the mouse pointer using
XGrabPointer(3X11).
Unfortunately due to the way the X
server works, the mouse can still be moved around by the
user at the physical display, but he will not be able to
change window focus with it. Also some window managers
that call
XGrabServer(3X11)
for resizes, etc, will
act on the local user's input. Again, some degree of
cooperation from the person at the display is assumed.
-viewpasswdstring
Supply a 2nd password for view-only logins. The -passwd
(full-access) password must also be supplied.
-passwdfilefilename
Specify the libvncserver password via the first line
of the file filename (instead of via -passwd on
the command line where others might see it via
ps(1)
).
See below for how to supply multiple passwords.
If the filename is prefixed with "rm:" it will be
removed after being read. Perhaps this is useful in
limiting the readability of the file. In general,
the password file should not be readable by untrusted
users (BTW: neither should the VNC -rfbauth file:
it is NOT encrypted, only obscured).
If the filename is prefixed with "read:" it will
periodically be checked for changes and reread.
Note that only the first 8 characters of a password
are used.
If multiple non-blank lines exist in the file they are
all taken as valid passwords. Blank lines are ignored.
Password lines may be "commented out" (ignored) if
they begin with the charactor "#" or the line contains
the string "__SKIP__". Lines may be annotated by use
of the "__COMM__" string: from it to the end of the
line is ignored. An empty password may be specified
via the "__EMPTY__" string on a line by itself (note
your viewer might not accept empty passwords).
If the string "__BEGIN_VIEWONLY__" appears on a
line by itself, the remaining passwords are used for
viewonly access. For compatibility, as a special case
if the file contains only two password lines the 2nd
one is automatically taken as the viewonly password.
Otherwise the "__BEGIN_VIEWONLY__" token must be
used to have viewonly passwords. (tip: make the 3rd
and last line be "__BEGIN_VIEWONLY__" to have 2
full-access passwords)
-displayWAIT:...
A special usage mode for the normal -display option.
Useful with -unixpw, but can be used independently
of it. If the display string begins with WAIT: then
x11vnc waits until a VNC client connects before opening
the X display (or -rawfb device).
This could be useful for delaying opening the display
for certain usage modes (say if x11vnc is started at
boot time and no X server is running or users logged
in yet).
If the string is, e.g. WAIT:0.0 or WAIT:1, i.e. "WAIT"
in front of a normal X display, then that indicated
display is used. A more interesting case is like this:
WAIT:cmd=/usr/local/bin/find_display
in which case the command after "cmd=" is run to
dynamically work out the DISPLAY and optionally the
XAUTHORITY data. The first line of the command output
must be of the form DISPLAY=<xdisplay>. Any remaining
output is taken as XAUTHORITY data. It can be either
of the form XAUTHORITY=<file> or raw xauthority data for
the display (e.g. "xauth extract - $DISPLAY" output).
As a special case, WAIT:cmd=FINDDISPLAY will run a
script that works on most Unixes to determine a user's
DISPLAY variable and xauthority data (see
who(1)
).
To have this default script printed to stdout (e.g. for
customization) run with WAIT:cmd=FINDDISPLAY-print
As another special case, WAIT:cmd=HTTPONCE will allow
x11vnc to service one http request and then exit.
This is usually done in -inetd mode to run on, say,
port 5800 and allow the Java vncviewer to be downloaded
by client web browsers. For example:
It is used in the Apache SSL-portal example (see FAQ).
Finally, one can insert a geometry between colons,
e.g. WAIT:1280x1024:... to set the size of the display
the VNC client first attaches to since some VNC viewers
will not automatically adjust to a new framebuffer size.
-usepw
If no other password method was supplied on the command
line, first look for ~/.vnc/passwd and if found use it
with -rfbauth; next, look for ~/.vnc/passwdfile and
use it with -passwdfile; otherwise, prompt the user
for a password to create ~/.vnc/passwd and use it with
the -rfbauth option. If none of these succeed x11vnc
exits immediately.
-storepasswdpassfile
Store password pass as the VNC password in the
file file. Once the password is stored the
program exits. Use the password via "-rfbauthfile"
If called with no arguments, "x11vnc -storepasswd",
the user is prompted for a password and it is stored
in the file ~/.vnc/passwd. Called with one argument,
that will be the file to store the prompted password in.
-nopw
Disable the big warning message when you use x11vnc
without some sort of password.
-acceptstring
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. string is
an external command run via
system(3)
or some special
cases described below. Be sure to quote string
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.
If x11vnc is running as root (say from
inetd(8)
or from
display managers
xdm(1)
,
gdm(1)
, etc), think about the
security implications carefully before supplying this
option (likewise for the -gone option).
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".
RFB_STATE will be PROTOCOL_VERSION, SECURITY_TYPE,
AUTHENTICATION, INITIALISATION, NORMAL, or UNKNOWN
indicating up to which state the client has acheived.
RFB_LOGIN_VIEWONLY will be 0, 1, or -1 (unknown).
RFB_USERNAME, RFB_LOGIN_TIME, and RFB_CURRENT_TIME may
also be set.
If string 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).
In the case of "popup" and when the -unixpw option
is specified, then a *second* window will be popped
up after the user successfully logs in via his UNIX
password. This time the user will be identified as
UNIX:username@hostname, the "UNIX:" prefix indicates
which user the viewer logged as via -unixpw. The first
popup is only for whether to allow him to even *try*
to login via unix password.
If string is "xmessage" then an
xmessage(1)
invocation is used for the command. xmessage must be
installed on the machine for this to work.
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
-viewonly has been specified, in which case the entire
display is view only.
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.
Note that x11vnc blocks while the external command
or popup is running (other clients may see no updates
during this period). So a person sitting a the physical
display is needed to respond to an popup prompt. (use
a 2nd x11vnc if you lock yourself out).
More -accept 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.
-afteracceptstring
As -accept, except to run a user supplied command after
a client has been accepted and authenticated. RFB_MODE
will be set to "afteraccept" and the other RFB_*
variables are as in -accept. Unlike -accept, the
command return code is not interpreted by x11vnc.
Example: -afteraccept 'killall xlock &'
-gonestring
As -accept, 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 -accept. The "popup" actions apply as well.
Unlike -accept, the command return code is not
interpreted by x11vnc. Example: -gone 'xlock &'
-userslist
If x11vnc is started as root (say from
inetd(8)
or from
display managers
xdm(1)
,
gdm(1)
, etc), then as soon
as possible after connections to the X display are
established try to switch to one of the users in the
comma separated list. If x11vnc is not running as
root this option is ignored.
Why use this option? In general it is not needed since
x11vnc is already connected to the X display and can
perform its primary functions. The option was added
to make some of the *external* utility commands x11vnc
occasionally runs work properly. In particular under
GNOME and KDE to implement the "-solidcolor" feature
external commands (gconftool-2 and dcop) unfortunately
must be run as the user owning the desktop session.
Since this option switches userid it also affects the
userid used to run the processes for the -accept and
-gone options. It also affects the ability to read
files for options such as -connect,-allow, and -remap.
Note that the -connect file is also sometimes written
to.
So be careful with this option since in some situations
its use can decrease security.
In general the switch to a user will only take place
if the display can still be successfully opened as that
user (this is primarily to try to guess the actual owner
of the session). Example: "-usersfred,wilma,betty".
Note that a malicious user "barney" by quickly using
"xhost +" when logging in may possibly get the x11vnc
process to switch to user "fred". What happens next?
Under display managers it may be a long time before
the switch succeeds (i.e. a user logs in). To instead
make it switch immediately regardless if the display
can be reopened prefix the username with the "+"
character. E.g. "-users+bob" or "-users+nobody".
The latter (i.e. switching immediately to user
"nobody") is probably the only use of this option
that increases security.
In -unixpw mode, if "-usersunixpw=" is supplied
then after a user authenticates himself via the
-unixpw mechanism, x11vnc will try to switch to that
user as though "-users+username" had been supplied.
If you want to limit which users this will be done for,
provide them as a comma separated list after "unixpw="
To immediately switch to a user *before* connections
to the X display are made or any files opened use the
"=" character: "-users=bob". That user needs to
be able to open the X display and any files of course.
The special user "guess=" means to examine the utmpx
database (see
who(1)
) looking for a user attached to
the display number (from DISPLAY or -display option)
and try him/her. To limit the list of guesses, use:
"-usersguess=bob,betty".
Even more sinister is the special user "lurk="
that means to try to guess the DISPLAY from the utmpx
login database as well. So it "lurks" waiting for
anyone to log into an X session and then connects to it.
Specify a list of users after the = to limit which users
will be tried. To enable a different searching mode, if
the first user in the list is something like ":0" or
":0-2" that indicates a range of DISPLAY numbers that
will be tried (regardless of whether they are in the
utmpx database) for all users that are logged in. Also
see the "-displayWAIT:..." functionality. Examples:
"-userslurk=" and also "-userslurk=:0-1,bob,mary"
Be especially careful using the "guess=" and "lurk="
modes. They are not recommended for use on machines
with untrustworthy local users.
-noshm
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 -onetile is not sufficient.
-flipbyteorder
Sometimes needed if remotely polled host has different
endianness. Ignored unless -noshm is set.
-onetile
Do not use the new copy_tiles() framebuffer mechanism,
just use 1 shm tile for polling. Limits shm segments
used to 3.
-solid[color]
To improve performance, when VNC clients are connected
try to change the desktop background to a solid color.
The [color] is optional: the default color is "cyan4".
For a different one specify the X color (rgb.txt name,
e.g. "darkblue" or numerical "#RRGGBB").
Currently this option only works on GNOME, KDE, CDE,
and classic X (i.e. with the background image on the
root window). The "gconftool-2" and "dcop" external
commands are run for GNOME and KDE respectively.
Other desktops won't work, e.g. Xfce (send us the
corresponding commands if you find them). If x11vnc is
running as root (
inetd(8)
or
gdm(1)
), the -users option
may be needed for GNOME and KDE. If x11vnc guesses
your desktop incorrectly, you can force it by prefixing
color with "gnome:", "kde:", "cde:" or "root:".
-blackoutstring
Black out rectangles on the screen. string is a
comma separated list of WxH+X+Y type geometries for
each rectangle. If one of the items on the list is the
string "noptr" the mouse pointer will not be allowed
to go into a blacked out region.
-xinerama,-noxinerama
If your screen is composed of multiple monitors
glued together via XINERAMA, and that screen is
not a rectangle this option will try to guess the
areas to black out (if your system has libXinerama).
default: -xinerama
In general, we have noticed on XINERAMA displays you
may need to use the "-xwarppointer" option if the mouse
pointer misbehaves.
-xtrap
Use the DEC-XTRAP extension for keystroke and mouse
input insertion. For use on legacy systems, e.g. X11R5,
running an incomplete or missing XTEST extension.
By default DEC-XTRAP will be used if XTEST server grab
control is missing, use -xtrap to do the keystroke and
mouse insertion via DEC-XTRAP as well.
-xrandr[mode]
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
xrandr(1)
manpage and run
'xrandr -q' for more info. [mode] is optional and
described below.
Since watching for XRANDR events and trapping 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).
"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.
-padgeomWxH
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 -xrandr,-remote id:windowid, rescaling, etc.)
-ologfile
Write stderr messages to file logfile instead of
to the terminal. Same as "-logfilefile". To append
to the file use "-oafile" or "-logappendfile".
-flagfile
Write the "PORT=NNNN" (e.g. PORT=5900) string to
file in addition to stdout. This option could be
useful by wrapper script to detect when x11vnc is ready.
-rcfilename
Use filename instead of $HOME/.x11vncrc for rc file.
-norc
Do not process any .x11vncrc file for options.
-envVAR=VALUE
Set the environment variable 'VAR' to value 'VALUE'
at x11vnc startup. This is a convenience utility to
avoid shell script wrappers, etc. to set the env. var.
You may specify as many of these as needed on the
command line.
-h,-help
Print this help text.
-?, -opts Only list the x11vnc options.
-V,-version
Print program version and last modification date.
-license
Print out license information. Same as -copying and
-warranty.
-dbg
Instead of exiting after cleaning up, run a simple
"debug crash shell" when fatal errors are trapped.
-q
Be quiet by printing less informational output to
stderr. Same as -quiet.
-bg
Go into the background after screen setup. Messages to
stderr are lost unless -o logfile is used. Something
like this could be useful in a script:
Option -modtweak 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: -modtweak
-xkb,-noxkb
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 -modtweak by itself.
The default is to check whether some common keysyms,
e.g. !, @, [, are only accessible via -xkb mode and if
so then automatically enable the mode. To disable this
automatic detection use -noxkb.
-capslock
When in -modtweak (the default) or -xkb mode,
if a keysym in the range A-Z comes in check the X
server to see if the Caps_Lock is set. If it is do
not artificially press Shift to generate the keysym.
This will enable the CapsLock key to behave correctly
in some circumstances: namely *both* the VNC viewer
machine and the x11vnc X server are in the CapsLock
on state. If one side has CapsLock on and the other
off and the keyboard is not behaving as you think it
should you should correct the CapsLock states (hint:
pressing CapsLock inside and outside of the viewer can
help toggle them both to the correct state). However,
for best results do not use this option, but rather
*only* enable CapsLock on the VNC viewer side (i.e. by
pressing CapsLock outside of the viewer window, also
-skip_lockkeys below). Also try -nomodtweak for a
possible workaround.
-skip_lockkeys
Have x11vnc ignore all Caps_Lock, Shift_Lock, Num_Lock,
Scroll_Lock keysyms received from viewers. The idea is
you press Caps_Lock on the VNC Viewer side but that does
not change the lock state in the x11vnc-side X server.
Nevertheless your capitalized letters come in over
the wire and are applied correctly to the x11vnc-side
X server. Note this mode probably won't do what you
want in -nomodtweak mode. Also, a kludge for KP_n
digits is always done it this mode: they are mapped to
regular digit keysyms. See also -capslock above.
-skip_keycodesstring
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 -xkb 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 -pk' to see your keymapping.
Example: "-skip_keycodes94,114"
-sloppy_keys
Experimental option that tries to correct some
"sloppy" key behavior. E.g. if at the viewer you
press Shift+Key but then release the Shift before
Key that could give rise to extra unwanted characters
(usually only between keyboards of different languages).
Only use this option if you observe problems with
some keystrokes.
-skip_dups,-noskip_dups
Some VNC viewers send impossible repeated key events,
e.g. key-down, key-down, key-up, key-up all for the same
key, or 20 downs in a row for the same modifier key!
Setting -skip_dups means to skip these duplicates and
just process the first event. Note: some VNC viewers
assume they can send down's without the corresponding
up's and so you should not set this option for
these viewers (symptom: some keys do not autorepeat)
Default: -noskip_dups
-add_keysyms,-noadd_keysyms
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 on an unused
key. Added Keysyms will be removed periodically and
also when x11vnc exits. Default: -add_keysyms
-clear_mods
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.
-clear_keys
As -clear_mods, except try to release any pressed key.
Note that this option and -clear_mods can interfere
with a person typing at the physical keyboard.
-remapstring
Read Keysym remappings from file named string.
Format is one pair of Keysyms per line (can be name
or hex value) separated by a space. If no file named
string 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
xev(1).
To map a key to a button click, use the fake Keysyms
"Button1", ..., etc. E.g: "-remapSuper_R-Button2"
(useful for pasting on a laptop)
To disable a keysym (i.e. make it so it will not be
injected), remap it to "NoSymbol" or "None".
Dead keys: "dead" (or silent, mute) keys are keys that
do not produce a character but must be followed by a 2nd
keystroke. This is often used for accenting characters,
e.g. to put "`" on top of "a" by pressing the dead
key and then "a". Note that this interpretation
is not part of core X11, it is up to the toolkit or
application to decide how to react to the sequence.
The X11 names for these keysyms are "dead_grave",
"dead_acute", etc. However some VNC viewers send the
keysyms "grave", "acute" instead thereby disabling
the accenting. To work around this -remap can be used.
For example "-remapgrave-dead_grave,acute-dead_acute"
As a convenience, "-remapDEAD" applies these remaps:
g grave-dead_grave
a acute-dead_acute
c asciicircum-dead_circumflex
t asciitilde-dead_tilde
m macron-dead_macron
b breve-dead_breve
D abovedot-dead_abovedot
d diaeresis-dead_diaeresis
o degree-dead_abovering
A doubleacute-dead_doubleacute
r caron-dead_caron
e cedilla-dead_cedilla
If you just want a subset use the first letter
label, e.g. "-remapDEAD=ga" to get the first two.
Additional remaps may also be supplied via commas,
e.g. "-remapDEAD=ga,Super_R-Button2". Finally,
"DEAD=missing" means to apply all of the above as
long as the left hand member is not already in the
X11 keymap.
-norepeat,-repeat
Option -norepeat disables X server key auto repeat when
VNC clients are connected and VNC keyboard input is
not idle for more than 5 minutes. 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).
Default: -norepeat
Note: your VNC viewer side will likely do autorepeating,
so this is no loss unless someone is simultaneously at
the real X display.
Use "-norepeatN" to set how many times norepeat will
be reset if something else (e.g. X session manager)
undoes it. The default is 2. Use a negative value
for unlimited resets.
-nofb
Ignore video framebuffer: only process keyboard and
pointer. Intended for use with Win2VNC and x2vnc
dual-monitor setups.
-nobell
Do not watch for XBell events. (no beeps will be heard)
Note: XBell monitoring requires the XKEYBOARD extension.
-nosel
Do not manage exchange of X selection/cutbuffer between
VNC viewers and the X server at all.
-noprimary
Do not poll the PRIMARY selection for changes to send
back to clients. (PRIMARY is still set on received
changes, however).
-nosetprimary
Do not set the PRIMARY selection for changes received
from VNC clients.
-noclipboard
Do not poll the CLIPBOARD selection for changes to send
back to clients. (CLIPBOARD is still set on received
changes, however).
-nosetclipboard
Do not set the CLIPBOARD selection for changes
received from VNC clients.
-seldirstring
If direction string is "send", only send the selection
to viewers, and if it is "recv" only receive it from
viewers. To work around apps setting the selection
too frequently and messing up the other end. You can
actually supply a comma separated list of directions,
including "debug" to turn on debugging output.
-cursor[mode],-nocursor
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 -nocursor to disable cursor shapes completely.
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 -nocursorshape and -nocursorpos
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.
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 -overlay (see also the
-overlay_nocursor 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 -noxfixes below). This can be disabled
with -nocursor, and also some values of the "mode"
option below.
Note that under XFIXES cursors with transparency (alpha
channel) will usually not be exactly represented and one
may find Overlay preferable. See also the -alphacut
and -alphafrac options below as fudge factors to try
to improve the situation for cursors with transparency
for a given theme.
The "mode" string can be used to fine-tune the
displaying of cursor shapes. It can be used the
following ways:
"-cursorarrow" - just show the standard arrow
nothing more or nothing less.
"-cursornone" - same as "-nocursor"
"-cursorX" - 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.
"-cursorsome" - 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.
"-cursormost" - 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, -overlay mode will be attempted.
-arrown
Choose an alternate "arrow" cursor from a set of
some common ones. n can be 1 to 6. Default is: 1
Ignored when in XFIXES cursor-grabbing mode.
-noxfixes
Do not use the XFIXES extension to draw the exact cursor
shape even if it is available.
-alphacutn
When using the XFIXES extension for the cursor shape,
cursors with transparency will not usually be displayed
exactly (but opaque ones will). This option sets n as
a cutoff for cursors that have transparency ("alpha
channel" with values ranging from 0 to 255) Any cursor
pixel with alpha value less than n becomes completely
transparent. Otherwise the pixel is completely opaque.
Default 240
-alphafracfraction
With the threshold in -alphacut some cursors will become
almost completely transparent because their alpha values
are not high enough. For those cursors adjust the
alpha threshold until fraction of the non-zero alpha
channel pixels become opaque. Default 0.33
-alpharemove
By default, XFIXES cursors pixels with transparency have
the alpha factor multiplied into the RGB color values
(i.e. that corresponding to blending the cursor with a
black background). Specify this option to remove the
alpha factor. (useful for light colored semi-transparent
cursors).
-noalphablend
In XFIXES mode do not send cursor alpha channel data
to libvncserver. The default is to send it. The
alphablend effect will only be visible in -nocursorshape
mode or for clients with cursorshapeupdates turned
off. (However there is a hack for 32bpp with depth 24,
it uses the extra 8 bits to store cursor transparency
for use with a hacked vncviewer that applies the
transparency locally. See the FAQ for more info).
-nocursorshape
Do not use the TightVNC CursorShapeUpdates extension
even if clients support it. See -cursor above.
-cursorpos,-nocursorpos
Option -cursorpos 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: -cursorpos
-xwarppointer
Move the pointer with
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.
-buttonmapstring
String to remap mouse buttons. Format: IJK-LMN, this
maps buttons I -> L, etc., e.g. -buttonmap 13-31
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:
-buttonmap 12345-123:Prior::Next:
-buttonmap 12345-123:Up+Up+Up::Down+Down+Down:
See <X11/keysymdef.h> header file for a list of Keysyms,
or use the
xev(1)
program. Note: mapping of button
clicks to Keysyms may not work if -modtweak or -xkb is
needed for the Keysym.
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.
-nodragging
Do not update the display during mouse dragging events
(mouse button held down). Greatly improves response on
slow setups, but you lose all visual feedback for drags,
text selection, and some menu traversals. It overrides
any -pointer_mode setting.
-wireframe[str],-nowireframe
Try to detect window moves or resizes when a mouse
button is held down and show a wireframe instead of
the full opaque window. This is based completely on
heuristics and may not always work: it depends on your
window manager and even how you move things around.
See -pointer_mode below for discussion of the "bogging
down" problem this tries to avoid.
Default: -wireframe
Shorter aliases: -wf [str] and -nowf
The value "str" is optional and, of course, is
packed with many tunable parameters for this scheme:
If you leave nothing between commas: ",," the default
value is used. If you don't specify enough commas,
the trailing parameters are set to their defaults.
"shade" indicate the "color" for the wireframe,
usually a greyscale: 0-255, however for 16 and 32bpp you
can specify an rgb.txt X color (e.g. "dodgerblue") or
a value > 255 is treated as RGB (e.g. red is 0xff0000).
"linewidth" sets the width of the wireframe in pixels.
"percent" indicates to not apply the wireframe scheme
to windows with area less than this percent of the
full screen.
"T+B+L+R" indicates four integers for how close in
pixels the pointer has to be from the Top, Bottom, Left,
or Right edges of the window to consider wireframing.
This is a speedup to quickly exclude a window from being
wireframed: set them all to zero to not try the speedup
(scrolling and selecting text will likely be slower).
"mod" specifies if a button down event in the
interior of the window with a modifier key (Alt, Shift,
etc.) down should indicate a wireframe opportunity.
It can be "0" or "none" to skip it, "1" or "all"
to apply it to any modifier, or "Shift", "Alt",
"Control", "Meta", "Super", or "Hyper" to only
apply for that type of modifier key.
"t1+t2+t3+t4" specify four floating point times in
seconds: t1 is how long to wait for the pointer to move,
t2 is how long to wait for the window to start moving
or being resized (for some window managers this can be
rather long), t3 is how long to keep a wireframe moving
before repainting the window. t4 is the minimum time
between sending wireframe "animations". If a slow
link is detected, these values may be automatically
changed to something better for a slow link.
-wirecopyrectmode,-nowirecopyrect
Since the -wireframe mechanism evidently tracks moving
windows accurately, a speedup can be obtained by
telling the VNC viewers to locally copy the translated
window region. This is the VNC CopyRect encoding:
the framebuffer update doesn't need to send the actual
new image data.
Shorter aliases: -wcr [mode] and -nowcr
"mode" can be "never" (same as -nowirecopyrect)
to never try the copyrect, "top" means only do it if
the window was not covered by any other windows, and
"always" means to translate the orginally unobscured
region (this may look odd as the remaining pieces come
in, but helps on a slow link). Default: "always"
Note: there can be painting errors or slow response
when using -scale so you may want to disable CopyRect
in this case "-wirecopyrectnever" on the command
line or by remote-control. Or you can also use the
"-scalexxx:nocr" scale option.
-debug_wireframe
Turn on debugging info printout for the wireframe
heuristics. "-dwf" is an alias. Specify multiple
times for more output.
-scrollcopyrectmode,-noscrollcopyrect
Like -wirecopyrect, but use heuristics to try to guess
if a window has scrolled its contents (either vertically
or horizontally). This requires the RECORD X extension
to "snoop" on X applications (currently for certain
XCopyArea and XConfigureWindow X protocol requests).
Examples: Hitting <Return> in a terminal window when the
cursor was at the bottom, the text scrolls up one line.
Hitting <Down> arrow in a web browser window, the web
page scrolls up a small amount. Or scrolling with a
scrollbar or mouse wheel.
Shorter aliases: -scr [mode] and -noscr
This scheme will not always detect scrolls, but when
it does there is a nice speedup from using the VNC
CopyRect encoding (see -wirecopyrect). The speedup
is both in reduced network traffic and reduced X
framebuffer polling/copying. On the other hand, it may
induce undesired transients (e.g. a terminal cursor
being scrolled up when it should not be) or other
painting errors (window tearing, bunching-up, etc).
These are automatically repaired in a short period
of time. If this is unacceptable disable the feature
with -noscrollcopyrect.
Screen clearing kludges: for testing at least, there
are some "magic key sequences" (must be done in less
than 1 second) to aid repairing painting errors that
may be seen when using this mode:
3 Alt_L's in a row: resend whole screen,
4 Alt_L's in a row: reread and resend whole screen,
3 Super_L's in a row: mark whole screen for polling,
4 Super_L's in a row: reset RECORD context,
5 Super_L's in a row: try to push a black screen
note: Alt_L is the Left "Alt" key (a single key)
Super_L is the Left "Super" key (Windows flag).
Both of these are modifier keys, and so should not
generate characters when pressed by themselves. Also,
your VNC viewer may have its own refresh hot-key
or button.
"mode" can be "never" (same as -noscrollcopyrect)
to never try the copyrect, "keys" means to try it
in response to keystrokes only, "mouse" means to
try it in response to mouse events only, "always"
means to do both. Default: "always"
Note: there can be painting errors or slow response
when using -scale so you may want to disable CopyRect
in this case "-scrollcopyrectnever" on the command
line or by remote-control. Or you can also use the
"-scalexxx:nocr" scale option.
-scr_arean
Set the minimum area in pixels for a rectangle
to be considered for the -scrollcopyrect detection
scheme. This is to avoid wasting the effort on small
rectangles that would be quickly updated the normal way.
E.g. suppose an app updated the position of its skinny
scrollbar first and then shifted the large panel
it controlled. We want to be sure to skip the small
scrollbar and get the large panel. Default: 60000
-scr_skiplist
Skip scroll detection for applications matching
the comma separated list of strings in list.
Some applications implement their scrolling in
strange ways where the XCopyArea, etc, also applies
to invisible portions of the window: if we CopyRect
those areas it looks awful during the scroll and
there may be painting errors left after the scroll.
Soffice.bin is the worst known offender.
Use "##" to denote the start of the application class
(e.g. "##XTerm") and "++" to denote the start
of the application instance name (e.g. "++xterm").
The string your list is matched against is of the form
"^^WM_NAME##Class++Instance<same-for-any-subwindows>"
The "xlsclients -la" command will provide this info.
If a pattern is prefixed with "KEY:" it only applies
to Keystroke generated scrolls (e.g. Up arrow). If it
is prefixed with "MOUSE:" it only applies to Mouse
induced scrolls (e.g. dragging on a scrollbar).
Default: ##Soffice.bin,##StarOffice
-scr_inclist
Opposite of -scr_skip: this list is consulted first
and if there is a match the window will be monitored
via RECORD for scrolls irrespective of -scr_skip.
Use -scr_skip '*' to skip anything that does not match
your -scr_inc. Use -scr_inc '*' to include everything.
-scr_keyslist
For keystroke scroll detection, only apply the RECORD
heuristics to the comma separated list of keysyms in
list. You may find the RECORD overhead for every
one of your keystrokes disrupts typing too much, but you
don't want to turn it off completely with "-scrmouse"
and -scr_parms does not work or is too confusing.
The listed keysyms can be numeric or the keysym
names in the <X11/keysymdef.h> header file or from the
xev(1)
program. Example: "-scr_keysUp,Down,Return".
One probably wants to have application specific lists
(e.g. for terminals, etc) but that is too icky to think
about for now...
If list begins with the "-" character the list
is taken as an exclude list: all keysyms except those
list will be considered. The special string "builtin"
expands to an internal list of keysyms that are likely
to cause scrolls. BTW, by default modifier keys,
Shift_L, Control_R, etc, are skipped since they almost
never induce scrolling by themselves.
-scr_termlist
Yet another cosmetic kludge. Apply shell/terminal
heuristics to applications matching comma separated
list (same as for -scr_skip/-scr_inc). For example an
annoying transient under scroll detection is if you
hit Enter in a terminal shell with full text window,
the solid text cursor block will be scrolled up.
So for a short time there are two (or more) block
cursors on the screen. There are similar scenarios,
(e.g. an output line is duplicated).
These transients are induced by the approximation of
scroll detection (e.g. it detects the scroll, but not
the fact that the block cursor was cleared just before
the scroll). In nearly all cases these transient errors
are repaired when the true X framebuffer is consulted
by the normal polling. But they are distracting, so
what this option provides is extra "padding" near the
bottom of the terminal window: a few extra lines near
the bottom will not be scrolled, but rather updated
from the actual X framebuffer. This usually reduces
the annoying artifacts. Use "none" to disable.
Default: "term"
-scr_keyrepeatlo-hi
If a key is held down (or otherwise repeats rapidly) and
this induces a rapid sequence of scrolls (e.g. holding
down an Arrow key) the "scrollcopyrect" detection
and overhead may not be able to keep up. A time per
single scroll estimate is performed and if that estimate
predicts a sustainable scrollrate of keys per second
between "lo" and "hi" then repeated keys will be
DISCARDED to maintain the scrollrate. For example your
key autorepeat may be 25 keys/sec, but for a large
window or slow link only 8 scrolls per second can be
sustained, then roughly 2 out of every 3 repeated keys
will be discarded during this period. Default: "4-20"
-scr_parmsstring
Set various parameters for the scrollcopyrect mode.
The format is similar to that for -wireframe and packed
with lots of parameters:
If you leave nothing between commas: ",," the default
value is used. If you don't specify enough commas,
the trailing parameters are set to their defaults.
"T+B+L+R" indicates four integers for how close in
pixels the pointer has to be from the Top, Bottom, Left,
or Right edges of the window to consider scrollcopyrect.
If -wireframe overlaps it takes precedence. This is a
speedup to quickly exclude a window from being watched
for scrollcopyrect: set them all to zero to not try
the speedup (things like selecting text will likely
be slower).
"t1+t2+t3" specify three floating point times in
seconds that apply to scrollcopyrect detection with
*Keystroke* input: t1 is how long to wait after a key
is pressed for the first scroll, t2 is how long to keep
looking after a Keystroke scroll for more scrolls.
t3 is how frequently to try to update surrounding
scrollbars outside of the scrolling area (0.0 to
disable)
"s1+s2+s3+s4+s5" specify five floating point times
in seconds that apply to scrollcopyrect detection with
*Mouse* input: s1 is how long to wait after a mouse
button is pressed for the first scroll, s2 is how long
to keep waiting for additional scrolls after the first
Mouse scroll was detected. s3 is how frequently to
try to update surrounding scrollbars outside of the
scrolling area (0.0 to disable). s4 is how long to
buffer pointer motion (to try to get fewer, bigger
mouse scrolls). s5 is the maximum time to spend just
updating the scroll window without updating the rest
of the screen.
-fixscreenstring
Periodically "repair" the screen based on settings
in string. Hopefully you won't need this option,
it is intended for cases when the -scrollcopyrect or
-wirecopyrect features leave too many painting errors,
but it can be used for any scenario. This option
periodically performs costly operations and so
interactive response may be reduced when it is on.
You can use 3 Alt_L's (the Left "Alt" key) taps in
a row (as described under -scrollcopyrect) instead to
manually request a screen repaint when it is needed.
string is a comma separated list of one or more of
the following: "V=t", "C=t", "X=t", and "8=t".
In these "t" stands for a time in seconds (it is
a floating point even though one should usually use
values > 2 to avoid wasting resources). V sets how
frequently the entire screen should be sent to viewers
(it is like the 3 Alt_L's). C sets how long to wait
after a CopyRect to repaint the full screen. X sets
how frequently to reread the full X11 framebuffer from
the X server and push it out to connected viewers.
Use of X should be rare, please report a bug if you
find you need it. 8= applies only for -8to24 mode: it
sets how often the non-default visual regions of the
screen (e.g. 8bpp windows) are refreshed. Examples:
-fixscreen V=10 -fixscreen C=10
-debug_scroll
Turn on debugging info printout for the scroll
heuristics. "-ds" is an alias. Specify it multiple
times for more output.
-noxrecord
Disable any use of the RECORD extension. This is
currently used by the -scrollcopyrect scheme and to
monitor X server grabs.
-grab_buster,-nograb_buster
Some of the use of the RECORD extension can leave a
tiny window for XGrabServer deadlock. This is only if
the whole-server grabbing application expects mouse or
keyboard input before releasing the grab. It is usually
a window manager that does this. x11vnc takes care to
avoid the the problem, but if caught x11vnc will freeze.
Without -grab_buster, the only solution is to go the
physical display and give it some input to satisfy the
grabbing app. Or manually kill and restart the window
manager if that is feasible. With -grab_buster, x11vnc
will fork a helper thread and if x11vnc appears to be
stuck in a grab after a period of time (20-30 sec) then
it will inject some user input: button clicks, Escape,
mouse motion, etc to try to break the grab. If you
experience a lot of grab deadlock, please report a bug.
-debug_grabs
Turn on debugging info printout with respect to
XGrabServer() deadlock for -scrollcopyrect__mode_.
-debug_sel
Turn on debugging info printout with respect to
PRIMARY, CLIPBOARD, and CUTBUFFER0 selections.
-pointer_moden
Various pointer motion update schemes. "-pm" is
an alias. The problem is pointer motion can cause
rapid changes on the screen: consider the rapid
changes when you drag a large window around opaquely.
Neither x11vnc's screen polling and vnc compression
routines nor the bandwidth to the vncviewers can keep
up these rapid screen changes: everything will bog down
when dragging or scrolling. So a scheme has to be used
to "eat" much of that pointer input before re-polling
the screen and sending out framebuffer updates. The
mode number n can be 0 to 4 and selects one of
the schemes desribed below.
Note that the -wireframe and -scrollcopyrect__mode_s
complement -pointer_mode by detecting (and improving)
certain periods of "rapid screen change".
n=0: does the same as -nodragging. (all screen polling
is suspended if a mouse button is pressed.)
n=1: was the original scheme used to about Jan 2004:
it basically just skips -input_skip keyboard or pointer
events before repolling the screen.
n=2 is an improved scheme: by watching the current rate
of input events it tries to detect if it should try to
"eat" additional pointer events before continuing.
n=3 is basically a dynamic -nodragging mode: it detects
when the mouse motion has paused and then refreshes
the display.
n=4 attempts to measures network rates and latency,
the video card read rate, and how many tiles have been
changed on the screen. From this, it aggressively tries
to push screen "frames" when it decides it has enough
resources to do so. NOT FINISHED.
The default n is 2. Note that modes 2, 3, 4 will skip
-input_skip keyboard events (but it will not count
pointer events). Also note that these modes are not
available in -threads mode which has its own pointer
event handling mechanism.
To try out the different pointer modes to see which
one gives the best response for your usage, it is
convenient to use the remote control function, for
example "x11vnc -R pm:4" or the tcl/tk gui (Tuning ->
pointer_mode -> n).
-input_skipn
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
-allinput
Have x11vnc read and process all available client input
before proceeding.
-speedsrd,bw,lat
x11vnc tries to estimate some speed parameters that
are used to optimize scheduling (e.g. -pointer_mode
4, -wireframe,-scrollcopyrect) and other things.
Use the -speeds option to set these manually.
The triple rd,bw,lat corresponds to video h/w
read rate in MB/sec, network bandwidth to clients in
KB/sec, and network latency to clients in milliseconds,
respectively. If a value is left blank, e.g. "-speeds
,100,15", then the internal scheme is used to estimate
the empty value(s).
Typical PC video cards have read rates of 5-10 MB/sec.
If the framebuffer is in main memory instead of video
h/w (e.g. SunRay, shadowfb, dummy driver, Xvfb), the
read rate may be much faster. "x11perf -getimage500"
can be used to get a lower bound (remember to factor
in the bytes per pixel). It is up to you to estimate
the network bandwith and latency to clients. For the
latency the
ping(1)
command can be used.
For convenience there are some aliases provided,
e.g. "-speedsmodem". The aliases are: "modem" for
6,4,200; "dsl" for 6,100,50; and "lan" for 6,5000,1
-wmdtstring
For some features, e.g. -wireframe and -scrollcopyrect,
x11vnc has to work around issues for certain window
managers or desktops (currently kde and xfce).
By default it tries to guess which one, but it can
guess incorrectly. Use this option to indicate which
wm/dt. string can be "gnome", "kde", "cde",
"xfce", or "root" (classic X wm). Anything else
is interpreted as "root".
-debug_pointer
Print debugging output for every pointer event.
-debug_keyboard
Print debugging output for every keyboard event.
Same as -dp and -dk, respectively. Use multiple
times for more output.
-defertime
Time in ms to wait for updates before sending to client
(deferUpdateTime) Default: 30
-waittime
Time in ms to pause between screen polls. Used to cut
down on load. Default: 30
-wait_uifactor
Factor by which to cut the -wait time if there
has been recent user input (pointer or keyboard).
Improves response, but increases the load whenever you
are moving the mouse or typing. Default: 2.00
-nowait_bog
Do not detect if the screen polling is "bogging down"
and sleep more. Some activities with no user input can
slow things down a lot: consider a large terminal window
with a long build running in it continously streaming
text output. By default x11vnc will try to detect this
(3 screen polls in a row each longer than 0.25 sec with
no user input), and sleep up to 1.5 secs to let things
"catch up". Use this option to disable that detection.
-slow_fbtime
Floating point time in seconds delay all screen polling.
For special purpose usage where a low frame rate is
acceptable and desirable, but you want the user input
processed at the normal rate so you cannot use -wait.
-readtimeoutn
Set libvncserver rfbMaxClientWait to n seconds. On
slow links that take a long time to paint the first
screen libvncserver may hit the timeout and drop the
connection. Default: 20 seconds.
-nap,-nonap
Monitor activity and if it is low take longer naps
between screen polls to really cut down load when idle.
Default: take naps
-sbtime
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
-nofbpm,-fbpm
If the system supports the FBPM (Frame Buffer Power
Management) extension (i.e. some Sun systems), then
prevent the video h/w from going into a reduced power
state when VNC clients are connected.
FBPM capable video h/w save energy when the workstation
is idle by going into low power states (similar to DPMS
for monitors). This interferes with x11vnc's polling
of the framebuffer data.
"-nofbpm" means prevent FBPM low power states whenever
VNC clients are connected, while "-fbpm" means to not
monitor the FBPM state at all. See the
xset(1)
manpage
for details. -nofbpm is basically the same as running
"xset fbpm force on" periodically. Default: -fbpm
-noxdamage
Do not use the X DAMAGE extension to detect framebuffer
changes even if it is available. Use -xdamage if your
default is to have it off.
x11vnc's use of the DAMAGE extension: 1) significantly
reduces the load when the screen is not changing much,
and 2) detects changed areas (small ones by default)
more quickly.
Currently the DAMAGE extension is overly conservative
and often reports large areas (e.g. a whole terminal
or browser window) as damaged even though the actual
changed region is much smaller (sometimes just a few
pixels). So heuristics were introduced to skip large
areas and use the damage rectangles only as "hints"
for the traditional scanline polling. The following
tuning parameters are introduced to adjust this
behavior:
-xd_areaA
Set the largest DAMAGE rectangle area A (in
pixels: width * height) to trust as truly damaged:
the rectangle will be copied from the framebuffer
(slow) no matter what. Set to zero to trust *all*
rectangles. Default: 20000
-xd_memf
Set how long DAMAGE rectangles should be "remembered",
f is a floating point number and is in units of the
scanline repeat cycle time (32 iterations). The default
(1.0) should give no painting problems. Increase it if
there are problems or decrease it to live on the edge
(perhaps useful on a slow machine).
-sigpipestring
Broken pipe (SIGPIPE) handling. string 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". This option
is obsolete.
-threads,-nothreads
Whether or not to use the threaded libvncserver
algorithm [rfbRunEventLoop] if libpthread is available
Default: -nothreads
-fsf
If the fraction of changed tiles in a poll is greater
than f, the whole screen is updated. Default: 0.75
-gapsn
Heuristic to fill in gaps in rows or cols of n or
less tiles. Used to improve text paging. Default: 4
-grown
Heuristic to grow islands of changed tiles n or wider
by checking the tile near the boundary. Default: 3
-fuzzn
Tolerance in pixels to mark a tiles edges as changed.
Default: 2
-debug_tiles
Print debugging output for tiles, fb updates, etc.
-snapfb
Instead of polling the X display framebuffer (fb) for
changes, periodically copy all of X display fb into main
memory and examine that copy for changes. Under some
circumstances this will improve interactive response,
or at least make things look smoother, but in others
(most!) it will make the response worse. If the video
h/w fb is such that reading small tiles is very slow
this mode could help. To keep the "framerate" up
the screen size x bpp cannot be too large. Note that
this mode is very wasteful of memory I/O resources
(it makes full screen copies even if nothing changes).
It may be of use in video capture-like applications,
or where window tearing is a problem.
-rawfbstring
Experimental option, instead of polling X, poll the
memory object specified in string.
For shared memory segments string is of the
form: "shm:N@WxHxB" which specifies a shmid
N and framebuffer Width, Height, and Bits
per pixel.
For file polling to memory map
mmap(2)
a file use:
"map:/path/to/a/file@WxHxB", with WxHxB as above.
"mmap:..." is the same. If there is trouble with mmap,
use "file:/..." for slower
lseek(2)
based reading.
Use "snap:..." to imply -snapfb mode and the "file:"
access (this is for devices that only provide the fb
all at once).
If you do not supply a type "map" is assumed if
the file exists (see the next paragraphs for some
exceptions to this.)
If string is "setup:cmd", then the command "cmd"
is run and the first line from it is read and used
as string. This allows initializing the device,
determining WxHxB, etc. These are often done as root
so take care.
If the string begins with "video", see the VIDEO4LINUX
discusion below where the device may be queried for
(and possibly set) the framebuffer parameters.
If the string begins with "console", "/dev/fb", or
"fb", see the LINUX CONSOLE discussion below where
the framebuffer device is opened and keystrokes (and
possibly mouse events) are inserted into the console.
Optional suffixes are ":R/G/B" and "+O" to specify
red, green, and blue masks and an offset into the
memory object. If the masks are not provided x11vnc
guesses them based on the bpp.
(see
ipcs(1)
and
fbset(1)
for the first two examples)
In general all user input is discarded by default (see
the -pipeinput option for how to use a helper program
to insert). Most of the X11 (screen, keyboard, mouse)
options do not make sense and many will cause this
mode to crash, so please think twice before setting or
changing them in a running x11vnc.
If you DO NOT want x11vnc to close the X DISPLAY in
rawfb mode, prepend a "+" e.g. +file:/dev/fb0...
Keeping the display open enables the default
remote-control channel, which could be useful.
Alternatively, if you specify -noviewonly, then the
mouse and keyboard input are STILL sent to the X
display, this usage should be very rare, i.e. doing
something strange with /dev/fb0.
If the device is not "seekable" try reading it all
at once in full snaps via the "snap:" mode (note:
this is a resource hog). If you are using file: or
map: and the device needs to be reopened for *every*
snapfb snapshot, set the environment variable:
SNAPFB_RAWFB_RESET=1 as well.
If you want x11vnc to dynamically transform a 24bpp
rawfb to 32bpp (note that this will be slower) also
supply the -24to32 option. This would be useful for,
say, a video camera that delivers the pixel data as
24bpp packed RGB. This is the default under "video"
mode if the bpp is 24.
VIDEO4LINUX: on Linux some attempt is made to handle
video devices (webcams or TV tuners) automatically.
The idea is the WxHxB will be extracted from the
device itself. So if you do not supply "@WxHxB...
parameters x11vnc will try to determine them. It first
tries the v4l API if that support has been compiled in.
Otherwise it will run the v4l-
info(1)
external program
if it is available.
The simplest examples are "-rawfbvideo" and "-rawfb
video1" which imply the device file /dev/video and
/dev/video1, respectively. You can also supply the
/dev if you like, e.g. "-rawfb/dev/video0"
Since the video capture device framebuffer usually
changes continuously (e.g. brightness fluctuations),
you may want to use the -wait,-slow_fb, or -defer
options to lower the "framerate" to cut down on
network VNC traffic.
A more sophisticated video device scheme allows
initializing the device's settings using:
-rawfb video:<settings>
The prefix could also be, as above, e.g. "video1:" to
specify the device file. The v4l API must be available
for this to work. Otherwise, you will need to try
to initialize the device with an external program,
e.g. xawtv, spcaview, and hope they persist when x11vnc
re-opens the device.
<settings> is a comma separated list of key=value pairs.
The device's brightness, color, contrast, and hue can
be set to percentages, e.g. br=80,co=50,cn=44,hu=60.
The device filename can be set too if needed (if it
does not start with "video"), e.g. fn=/dev/qcam.
The width, height and bpp of the framebuffer can be
set via, e.g., w=160,h=120,bpp=16.
Related to the bpp above, the pixel format can be set
via the fmt=XXX, where XXX can be one of: GREY, HI240,
RGB555, RGB565, RGB24, and RGB32 (with bpp 8, 8, 16, 16,
24, and 32 respectively). See http://www.linuxtv.org
for more info (V4L api).
For TV/rf tuner cards one can set the tuning mode
via tun=XXX where XXX can be one of PAL, NTSC, SECAM,
or AUTO.
One can switch the input channel by the inp=XXX setting,
where XXX is the name of the input channel (Television,
Composite1, S-Video, etc). Use the name that is in the
information about the device that is printed at startup.
For input channels with tuners (e.g. Television) one
can change which station is selected by the sta=XXX
setting. XXX is the station number. Currently only
the ntsc-cable-us (US cable) channels are built into
x11vnc. See the -freqtab option below to supply one
from xawtv. If XXX is greater than 500, then it is
interpreted as a raw frequency in KHz.
one might need to add inp=Television too for the input
channel to be TV if the card doesn't come up by default
in that one.
Note that not all video capture devices will support
all of the above settings.
See the -pipeinput VID option below for a way to control
the settings through the VNC Viewer via keystrokes.
As a shortcut, if the string begins "Video.." instead
of "video.." then -pipeinput VID is implied.
As above, if you specify a "@WxHxB..." after the
<settings> string they are used verbatim: the device
is not queried for the current values. Otherwise the
device will be queried.
LINUX CONSOLE: If the libvncserver LinuxVNC program
is on your system you may want to use that instead of
the following method because it will be faster and more
accurate for Linux text console.
If the rawfb string begins with "console" the
framebuffer device /dev/fb0 is opened (this requires
the appropriate kernel modules to be installed) and so
is /dev/tty0. The latter is used to inject keystrokes
(not all are supported, but the basic ones are).
You will need to be root to inject keystrokes.
/dev/tty0 refers to the active VT, to indicate one
explicitly, use "console2", etc. using the VT number.
If the Linux version seems to be 2.6 or later and the
"uinput" module appears to be present, then the uinput
method will be used instead of /dev/ttyN. uinput allows
insertion of BOTH keystrokes and mouse input and so it
preferred when accessing graphical (e.g. QT-embedded)
linux console apps. See -pipeinput UINPUT below for
more information on this mode; you will have to use
-pipeinput if you want to tweak any UINPUT parameters.
You may also want to also use the -nodragging and
-cursor none options. Use "console0", etc or
-pipeinput CONSOLE to force the /dev/ttyN method.
Note you can change VT remotely using the
chvt(1)
command. Sometimes switching out and back corrects
the framebuffer state.
To skip input injecting entirely use "consolex".
The string "/dev/fb0" (1, etc.) can be used instead
of "console". This can be used to specify a different
framebuffer device, e.g. /dev/fb1. As a shortcut the
"/dev/" can be dropped. If the name is something
nonstandard, use "console:/dev/foofb"
If you do not want x11vnc to guess the framebuffer's
WxHxB and masks automatically (sometimes the kernel
given inaccurate information), specify them with a
@WxHxB at the end of the string.
Examples:
-rawfb console (same as -rawfb console)
-rawfb /dev/fb0 (same)
-rawfb console3 (force /dev/tty3)
-rawfb consolex (no keystrokes or mouse)
-rawfb console:/dev/nonstd
-rawfb console -pipeinput UINPUT:accel=4.0
-freqtabfile
For use with "-rawfbvideo" for TV tuner devices to
specify station frequencies. Instead of using the built
in ntsc-cable-us mapping of station number to frequency,
use the data in file. For stations that are not
numeric, e.g. SE20, they are placed above the highest
numbered station in the order they are found. Example:
"-freqtab/usr/X11R6/share/xawtv/europe-west.list"
You can make your own freqtab by copying the xawtv
format.
-pipeinputcmd
Another experimental option: it lets you supply an
external command in cmd that x11vnc will pipe
all of the user input events to in a simple format.
In -pipeinput mode by default x11vnc will not process
any of the user input events. If you prefix cmd
with "tee:" it will both send them to the pipe
command and process them. For a description of the
format run "-pipeinputtee:/bin/cat". Another prefix
is "reopen" which means to reopen pipe if it exits.
Separate multiple prefixes with commas.
In combination with -rawfb one might be able to
do amusing things (e.g. control non-X devices).
To facilitate this, if -rawfb is in effect then the
value is stored in X11VNC_RAWFB_STR for the pipe command
to use if it wants. Do 'env | grep X11VNC' for more.
Built-in pipeinput modes (no external program required):
If cmd is "VID" and you are using the -rawfb for a
video capture device, then an internal list of keyboard
mappings is used to set parameters of the video.
The mappings are:
"B" and "b" adjust the brightness up and down.
"H" and "h" adjust the hue.
"C" and "c" adjust the colour.
"N" and "n" adjust the contrast.
"S" and "s" adjust the size of the capture screen.
"I" and "i" cycle through input channels.
Up and Down arrows adjust the station (if a tuner)
F1, F2, ..., F6 will switch the video capture pixel
format to HI240, RGB565, RGB24, RGB32, RGB555, and
GREY respectively. See -rawfb video for details.
If cmd is "CONSOLE" or "CONSOLEn" where n
is a Linux console number, then the linux console
keystroke insertion to /dev/ttyN (see -rawfb console)
is performed.
If cmd begins with "UINPUT" then the Linux uinput
module is used to insert both keystroke and mouse events
to the Linux console (see -rawfb above). This usually
is the /dev/input/uinput device file (you may need to
create it with "mknod /dev/input/uinput c 10 223"
and insert the module with "modprobe uinput".
The UINPUT mode currently only does US keyboards (a
scan code option may be added), and not all keysyms
are supported.
You may want to use the options -cursor none and
-nodragging in this mode.
Additional tuning options may be supplied via:
UINPUT:opt1,opt2,... (a comma separated list). If an
option begins with "/" it is taken as the uinput
device file.
Which uinput is injected can be controlled by an option
string made of the characters "K", "M", and "B"
(see the -input option), e.g. "KM" allows keystroke
and motion but not button clicks.
A UINPUT option of the form: accel=f, or accel=fx+fy
sets the mouse motion "acceleration". This is used
to correct raw mouse relative motion into how much the
application cursor moves (x11vnc has no control over,
or knowledge of how the windowing application interprets
the raw mouse motions). Typically the acceleration
for an X display is 2 (see xset "m" option). "f"
is a floating point number, e.g. 3.0. Use "fx+fy"
if you need to supply different corrections for x and y.
Note: the default acceleration is 2.0 since it seems
both X and qt-embedded often (but not always) use
this value.
Even with a correct accel setting the mouse position
will get out of sync (probably due to a mouse
"threshold" setting where the acceleration doe not
apply, set
xset(1)
). The option reset=N sets the
number of ms (default 150) after which the cursor is
attempted to be reset (by forcing the mouse to (0,
0) via small increments and then back out to (x, y)
in 1 jump), This correction seems to be needed but can
cause jerkiness or unexpected behavior with menus, etc.
Use reset=0 to disable.
If you set the env. var X11VNC_UINPUT_THRESHOLDS then
the thresh=n mode will be enabled. It it currently
not working well. If |dx| <= thresh and |dy| < thresh
no acceleration is applied. Use "thresh=+n" |dx| +
|dy| < thresh to be used instead (X11?)
Example:
-pipeinput UINPUT:accel=4.0 -cursor none
You can also set the env. var X11VNC_UINPUT_DEBUG=1 or
higher to get debugging output for UINPUT mode.
-gui[gui-opts]
Start up a simple tcl/tk gui based on the the remote
control options -remote/-query 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 full gui and x11vnc with the
gui showing up on the X display in the environment
variable DISPLAY.
"gui-opts" can be a comma separated list of items.
Currently there are these types of items: 1) a gui
mode, a 2) gui "simplicity", 3) the X display the
gui should display on, 4) a "tray" or "icon" mode,
and 5) a gui geometry.
1) 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.)
2) The gui simplicity is off by default (a power-user
gui with all options is presented) To start with
something less daunting supply the string "simple"
("ez" is an alias for this). Once the gui is
started you can toggle between the two with "Misc ->
simple_gui".
3) 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).
If you do not specify a gui X display in "gui-opts"
then the DISPLAY environment variable and -display
option are tried (in that order). Regarding the x11vnc
X display the gui will try to communication with, it
first tries -display and then DISPLAY. For example,
"x11vnc -display :0 -gui otherhost:0", will remote
control an x11vnc polling :0 and display the gui on
otherhost:0 The "tray/icon" mode below reverses this
preference, preferring to display on the x11vnc display.
4) When "tray" or "icon" is specified, the gui
presents itself as a small icon with behavior typical
of a "system tray" or "dock applet". The color
of the icon indicates status (connected clients) and
there is also a balloon status. Clicking on the icon
gives a menu from which properties, etc, can be set and
the full gui is available under "Advanced". To be
fully functional, the gui mode should be "start"
(the default).
For "icon" the gui just a small standalone window.
For "tray" it will attempt to embed itself in the
"system tray" if possible. If "=setpass" is appended then
at startup the X11 user will be prompted to set the
VNC session password. If =<hexnumber> is appended
that icon will attempt to embed itself in the window
given by hexnumber. Use =noadvanced to disable the
full gui. (To supply more than one, use "+" sign).
E.g. -gui tray=setpass and -gui icon=0x3600028
Other modes: "full", the default and need not be
specified. "-guinone", do not show a gui, useful
to override a ~/.x11vncrc setting, etc.
5) When "geom=+X+Y" is specified, that geometry
is passed to the gui toplevel. This is the icon in
icon/tray mode, or the full gui otherwise. You can
also specify width and height, i.e. WxH+X+Y, but it
is not recommended. In "tray" mode the geometry is
ignored unless the system tray manager does not seem
to be running. One could imagine using something like
"-guitray,geom=+4000+4000" with a display manager
to keep the gui invisible until someone logs in...
More icon tricks, "icon=minimal" gives an icon just
with the VNC display number. You can also set the font
with "iconfont=...". The following could be useful:
"-guiicon=minimal,iconfont=5x8,geom=24x10+0-0"
General examples of the -gui option: "x11vnc -gui",
"x11vnc -gui ez" "x11vnc -gui localhost:10",
"x11vnc -gui conn,host:0", "x11vnc -gui tray,ez"
"x11vnc -gui tray=setpass"
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.
-remotecommand
Remotely control some aspects of an already running
x11vnc server. "-R" and "-r" are aliases for
"-remote". After the remote control command is
sent to the running server the 'x11vnc -remote ...'
command exits. You can often use the -query command
(see below) to see if the x11vnc server processed your
-remote command.
The default communication channel is that of X
properties (specifically X11VNC_REMOTE), 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 -display
and -auth options to set them to the correct values.
The running server cannot use the -novncconnect option
because that disables the communication channel.
See below for alternate channels.
For example: 'x11vnc -remote stop' (which is the same as
'x11vnc -R stop') will close down the x11vnc server.
'x11vnc -R shared' will enable shared connections, and
'x11vnc -R scale:3/4' will rescale the desktop.
The following -remote/-R commands are supported:
stop terminate the server, same as "quit"
"exit" or "shutdown".
ping see if the x11vnc server responds.
Return is: ans=ping:<xdisplay>
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.
refresh send the entire fb to all clients.
reset recreate the fb, polling memory, etc.
id:windowid set -id window to "windowid". empty
or "root" to go back to root window
sid:windowid set -sid window to "windowid"
waitmapped wait until subwin is mapped.
nowaitmapped do not wait until subwin is mapped.
clip:WxH+X+Y set -clip mode to "WxH+X+Y"
flashcmap enable -flashcmap mode.
noflashcmap disable -flashcmap mode.
shiftcmap:n set -shiftcmap to n.
notruecolor enable -notruecolor mode.
truecolor disable -notruecolor mode.
overlay enable -overlay mode (if applicable).
nooverlay disable -overlay mode.
overlay_cursor in -overlay mode, enable cursor drawing.
overlay_nocursor disable cursor drawing. same as
nooverlay_cursor.
8to24 enable -8to24 mode (if applicable).
no8to24 disable -8to24 mode.
8to24_opts:str set the -8to24 opts to "str".
24to32 enable -24to32 mode (if applicable).
no24to32 disable -24to32 mode.
visual:vis set -visual to "vis"
scale:frac set -scale to "frac"
scale_cursor:f set -scale_cursor to "f"
viewonly enable -viewonly mode.
noviewonly disable -viewonly mode.
shared enable -shared mode.
noshared disable -shared mode.
forever enable -forever mode.
noforever disable -forever mode.
timeout:n reset -timeout to n, if there are
currently no clients, exit unless one
connects in the next n secs.
filexfer enable filetransfer for new clients.
nofilexfer disable filetransfer for new clients.
http enable http client connections.
nohttp disable http client connections.
deny deny any new connections, same as "lock"
nodeny allow new connections, same as "unlock"
connect:host do reverse connection to host, "host"
may be a comma separated list of hosts
or host:ports. See -connect. Passwords
required as with fwd connections.
See X11VNC_REVERSE_CONNECTION_NO_AUTH=1
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 "-queryclients"
and RFB_CLIENT_ID) you can use that too.
allowonce:host For the next connection only, allow
connection from "host".
allow:hostlist set -allow list to (comma separated)
"hostlist". See -allow and -localhost.
Do not use with -allow /path/to/file
Use "+host" to add a single host, and
use "-host" to delete a single host
localhost enable -localhost mode
nolocalhost disable -localhost mode
listen:str set -listen to str, empty to disable.
nolookup enable -nolookup mode.
lookup disable -nolookup mode.
input:str set -input to "str", empty to disable.
grabkbd enable -grabkbd mode.
nograbkbd disable -grabkbd mode.
grabptr enable -grabptr mode.
nograbptr disable -grabptr mode.
client_input:str set the K, M, B -input on a per-client
basis. select which client as for
disconnect, e.g. client_input:host:MB
or client_input:0x2:K
accept:cmd set -accept "cmd" (empty to disable).
afteraccept:cmd set -afteraccept (empty to disable).
gone:cmd set -gone "cmd" (empty to disable).
noshm enable -noshm mode.
shm disable -noshm mode (i.e. use shm).
flipbyteorder enable -flipbyteorder mode, you may need
to set noshm for this to do something.
noflipbyteorder disable -flipbyteorder mode.
onetile enable -onetile mode. (you may need to
set shm for this to do something)
noonetile disable -onetile mode.
solid enable -solid mode
nosolid disable -solid mode.
solid_color:color set -solid color (and apply it).
blackout:str set -blackout "str" (empty to disable).
See -blackout 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
xinerama enable -xinerama mode. (if applicable)
noxinerama disable -xinerama mode.
xtrap enable -xtrap input mode(if applicable)
noxtrap disable -xtrap input mode.
xrandr enable -xrandr mode. (if applicable)
noxrandr disable -xrandr mode.
xrandr_mode:mode set the -xrandr mode to "mode".
padgeom:WxH set -padgeom to WxH (empty to disable)
If WxH is "force" or "do" the padded
geometry fb is immediately applied.
noadd_keysyms stop adding keysyms. those added will
still be removed at exit.
clear_mods enable -clear_mods mode and clear them.
noclear_mods disable -clear_mods mode.
clear_keys enable -clear_keys mode and clear them.
noclear_keys disable -clear_keys mode.
remap:str set -remap "str" (empty to disable).
See -remap for the form of "str"
(basically: key1-key2,key3-key4,...)
Use "+key1-key2" to append a single
keymapping, use "-key1-key2" to delete.
norepeat enable -norepeat mode.
repeat disable -norepeat mode.
nofb enable -nofb mode.
fb disable -nofb mode.
bell enable bell (if supported).
nobell disable bell.
nosel enable -nosel mode.
sel disable -nosel mode.
noprimary enable -noprimary mode.
primary disable -noprimary mode.
nosetprimary enable -nosetprimary mode.
setprimary disable -nosetprimary mode.
noclipboard enable -noclipboard mode.
clipboard disable -noclipboard mode.
nosetclipboard enable -nosetclipboard mode.
setclipboard disable -nosetclipboard mode.
seldir:str set -seldir to "str"
cursor:mode enable -cursor "mode".
show_cursor enable showing a cursor.
noshow_cursor disable showing a cursor. (same as
"nocursor")
arrow:n set -arrow to alternate n.
xfixes enable xfixes cursor shape mode.
noxfixes disable xfixes cursor shape mode.
alphacut:n set -alphacut to n.
alphafrac:f set -alphafrac to f.
alpharemove enable -alpharemove mode.
noalpharemove disable -alpharemove mode.
alphablend disable -noalphablend mode.
noalphablend enable -noalphablend mode.
cursorshape disable -nocursorshape mode.
nocursorshape enable -nocursorshape mode.
cursorpos disable -nocursorpos mode.
nocursorpos enable -nocursorpos mode.
xwarp enable -xwarppointer mode.
noxwarp disable -xwarppointer mode.
buttonmap:str set -buttonmap "str", empty to disable
dragging disable -nodragging mode.
nodragging enable -nodragging mode.
wireframe enable -wireframe mode. same as "wf"
nowireframe disable -wireframe mode. same as "nowf"
wireframe:str enable -wireframe mode string.
wireframe_mode:str enable -wireframe mode string.
wirecopyrect:str set -wirecopyrect string. same as "wcr:"
scrollcopyrect:str set -scrollcopyrect string. same "scr"
or you can directly write to the file via something
like: "echo cmd=stop > /path/to/file", etc.
-queryvariable
Like -remote, except just query the value of
variable. "-Q" is an alias for "-query".
Multiple queries can be done by separating variables
by commas, e.g. -query 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=".
Some -remote 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 X11VNC_REMOTE property or connect
file use "qry=..." instead of "cmd=..."
Just like -query variable, but returns the default
value for that parameter (no running x11vnc server
is consulted)
-sync
By default -remote commands are run asynchronously, that
is, the request is posted and the program immediately
exits. Use -sync to have the program wait for an
acknowledgement from the x11vnc server that command was
processed (somehow). On the other hand -query requests
are always processed synchronously because they have
to wait for the answer.
Also note that if both -remote and -query requests are
supplied on the command line, the -remote is processed
first (synchronously: no need for -sync), and then
the -query request is processed in the normal way.
This allows for a reliable way to see if the -remote
command was processed by querying for any new settings.
Note however that there is timeout of a few seconds so
if the x11vnc takes longer than that to process the
requests the requestor will think that a failure has
taken place.
-noremote,-yesremote
Do not process any remote control commands or queries.
Do process remote control commands or queries.
Default: -yesremote
A note about security wrt remote control commands.
If someone can connect to the X display and change
the property X11VNC_REMOTE, then they can remotely
control x11vnc. Normally access to the X display is
protected. Note that if they can modify X11VNC_REMOTE
on the X server, they have enough permissions to also
run their own x11vnc and thus have complete control
of the desktop. If the "-connect/path/to/file"
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. See -privremote below.
If you are paranoid and do not think -noremote is
enough, to disable the X11VNC_REMOTE property channel
completely use -novncconnect, or use the -safer option
that shuts many things off.
-unsafe
A few remote commands are disabled by default
(currently: id:pick, accept:<cmd>, gone:<cmd>, and
rawfb:setup:<cmd>) because they are associated with
running external programs. If you specify -unsafe, then
these remote-control commands are allowed. Note that
you can still specify these parameters on the command
line, they just cannot be invoked via remote-control.
-safer
Equivalent to: -novncconnect-noremote and prohibiting
-gui and the -connect file. Shuts off communcation
channels.
-privremote
Perform some sanity checks and disable remote-control
commands if it appears that the X DISPLAY and/or
connectfile can be accessed by other users. Once
remote-control is disabled it cannot be turned back on.
-nocmds
No external commands (e.g.
system(3)
,
popen(3)
,
exec(3)
)
will be run.
-allowedcmdslist
list contains a comma separated list of the only
external commands that can be run. The full list of
associated options is: