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x11vnc README file Date: Sat Mar 12 18:06:15 EST 2005
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The following information is taken from these URLs:
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http://www.karlrunge.com/x11vnc/index.html
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http://www.karlrunge.com/x11vnc/x11vnc_opts.html
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they contain the most up to date info.
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=======================================================================
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http://www.karlrunge.com/x11vnc/index.html:
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_________________________________________________________________
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x11vnc: a VNC server for real X displays (to [1]FAQ) (to [2]Downloads)
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(to [3]Building)
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x11vnc allows one to remotely view and interact with real X displays
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(i.e. a display corresponding to a physical monitor, keyboard, and
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mouse) with any VNC viewer. In this way it plays the role for Unix/X11
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that WinVNC plays for Windows.
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I wrote x11vnc because x0rfbserver was basically impossible to build
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on Solaris and had poor performance. The primary x0rfbserver build
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problems centered around esoteric C++ toolkits. x11vnc is written in
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plain C and uses only standard libraries. I also added a few
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enhancements to improve the interactive response, add esoteric
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features, etc. The [4]FAQ contains a lot of information and solutions
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to problems, but please feel free to [5]contact me if you have
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problems or questions.
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Background:
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VNC (Virtual Network Computing) is a very useful network graphics
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protocol (applications running on one computer but displaying their
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windows on another) in the spirit of X, however, unlike X, the
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viewing-end is very simple and maintains no state. It is a remote
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framebuffer (RFB) protocol
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Some VNC links:
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* [6]http://www.uk.research.att.com/vnc/
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* [7]http://www.realvnc.com
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* [8]http://www.tightvnc.com
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For Unix, the VNC implementation includes a virtual X11 server Xvnc
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(usually launched via the vncserver command) that is not associated
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with a physical display, but provides a "fake" one X11 clients (xterm,
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mozilla, etc.) can attach to. A remote user then connects to Xvnc via
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the VNC client vncviewer from anywhere on the network to view and
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interact with the whole virtual X11 desktop.
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The VNC protocol is in most cases better suited for remote connections
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with low bandwidth and high latency than is the X11 protocol (the
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exception is cached pixmap data on the viewing-end). Also, with no
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state maintained the viewing-end can crash, be rebooted, or relocated
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and the applications and desktop continue running. Not so with X11.
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So the standard Xvnc/vncserver program is very useful, I use it for
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things like:
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* Desktop conferencing with other users (e.g. codereviews).
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* Long running apps/tasks I want to be able to view from many
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places.
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* Motif, GNOME, and similar applications that would yield very poor
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performance over a high latency link.
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However, sometimes one wants to connect to a real X11 display (i.e.
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one attached to a physical monitor, keyboard, and mouse: a Workstation
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or a SunRay session) from far away. Maybe you want to close down an
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application cleanly rather than using kill, or want to work a bit in
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an already running application, or would like to help a distant
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colleague solve a problem with their desktop. This is where x11vnc is
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useful.
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_________________________________________________________________
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How to use x11vnc:
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In this basic example let's assume the remote machine with the X
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display you wish to view is "far-away.east:0" and the workstation you
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are presently working at is "sitting-here.west".
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Step 0. Download x11vnc ([9]see below) and have it available to run on
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far-away.east. Similarly, have a VNC viewer (e.g. vncviewer) ready to
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run on sitting-here.west. We recommend [10]TightVNC Viewers.
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Step 1. By some means log in to far-away.east and get a command shell
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running there. You can use ssh, rlogin, telnet, or any other method to
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do this. x11vnc needs to be run on the same machine the X server
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process is running on (otherwise things would be extremely slow).
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Step 2. In that far-away.east shell (with command prompt "far-away>"
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in this example) run x11vnc directed at the far-away.east X session
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display:
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far-away> x11vnc -display :0
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You could have also set the environment variable DISPLAY=:0 instead of
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using -display. This step attaches x11vnc to the far-away.east:0 X
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display (no viewer clients yet).
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To get X11 permissions right, you may also need to set the XAUTHORITY
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environment variable (or use the [11]-auth option) to point to the
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correct MIT-MAGIC-COOKIE file (e.g. /home/joe/.Xauthority). More on
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this [12]below.
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There will then be much chatter printed out from x11vnc, until it
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finally says something like:
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.
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.
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13/05/2004 14:59:54 Autoprobing selected port 5900
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13/05/2004 14:59:54 screen setup finished.
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13/05/2004 14:59:54 The VNC desktop is far-away:0
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PORT=5900
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which means all is OK, and we are ready for the final step.
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Step 3. At the place where you are sitting (sitting-here.west in this
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example) you now want to run a VNC viewer program. There are VNC
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viewers for Unix, Windows, MacOS, Java-enabled web browsers, and even
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for PDA's like the Palm Pilot! You can use any of them to connect to
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x11vnc (see the above VNC links under "Background:" on how to obtain a
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viewer for your platform or see [13]this FAQ. For Solaris, vncviewer
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is available in the [14]Companion CD package SFWvnc ).
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In this example we'll use the Unix vncviewer program on sitting-here
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by typing the following command in a second terminal window:
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sitting-here> vncviewer far-away.east:0
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That should pop up a viewer window on sitting-here.west showing and
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allowing interaction with the far-away.east:0 X11 desktop. Pretty
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nifty! When finished, exit the viewer: the remote x11vnc process will
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shutdown automatically (or you can use the [15]-forever option to have
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it wait for additional viewer connections).
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Shortcut: Of course if you left x11vnc running on far-away.east:0 in a
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terminal window with the [16]-forever option or as a [17]service,
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you'd only have to do Step 3 as you moved around. Be sure to use a VNC
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[18]password or [19]other measures if you do that.
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Desktop Sharing: The above more or less assumed nobody was sitting at
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the workstation display "far-away.east:0". This is often the case: a
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user wants to access her workstation remotely. Another usage pattern
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has the user sitting at "far-away.east:0" and invites one or more
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other people to view and interact with his desktop. Perhaps the user
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gives a demo or presentation this way (using the telephone for vocal
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communication). A "Remote Help Desk" mode would be similar: a
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technician remotely connects to the user's desktop to interactively
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solve a problem the user is having.
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For these cases it should be obvious how it is done. The above steps
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will work, but more easily the user sitting at far-away.east:0 simply
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starts up x11vnc from a terminal window, after which the guests would
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start their VNC viewers. For this usage mode the "[20]-connect
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host1,host2" option may be of use automatically connect to vncviewers
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in "-listen" mode on the list of hosts.
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_________________________________________________________________
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Tunnelling x11vnc via ssh:
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The above example had no security or privacy at all. When logging into
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remote machines (certainly when going over the internet) it is best to
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use ssh, or use a VPN. For x11vnc one can tunnel the VNC protocol
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through the encrypted ssh channel. It would look something like this:
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sitting-here> ssh -L 5900:localhost:5900 far-away.east 'x11vnc -display :0'
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(you will likely have to provide passwords/passphrases for the ssh
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login) and then in another terminal window on sitting-here run the
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command:
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sitting-here> vncviewer -encodings "copyrect tight zrle hextile" localhost:0
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The -encodings option is very important: vncviewer will default to
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"raw" encoding if it thinks the connection is to the local machine,
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and so vncviewer gets tricked this way by the ssh redirection. "raw"
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encoding will be extremely slow over a networked link, so you need to
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force the issue with -encodings "copyrect tight ...".
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Some VNC viewers will do the ssh tunnelling for you automatically, the
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TightVNC vncviewer does this when the "-via far-away.east" option is
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supplied to it (this requires x11vnc to be already running on
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far-away.east or having it started by [21]inetd(1)). See the 3rd
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script example [22]below for more info.
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If the machine you SSH into is not the same machine with the X display
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you wish to view (e.g. your company provides incoming SSH access to a
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gateway machine), then you need to change the above to, e.g.: "-L
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5900:otherhost:5900". Once logged in, you'll need to do a second login
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(ssh, rsh, etc.) to the workstation machine 'otherhost' and then start
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up x11vnc on it if it isn't already running.
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_________________________________________________________________
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Scripts to automate ssh tunneling: As discussed below, there may be
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some problems with port 5900 being available. If that happens, the
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above port and display numbers may change a bit (e.g. -> 5901 and :1).
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However, if you "know" port 5900 will be free on the local and remote
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machines, you can easily automate the above two steps by using the
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x11vnc option [23]-bg (forks into background after connection to the
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display is set up) or using the -f option of ssh. Three example
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scripts are shown below.
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_________________________________________________________________
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#1. A simple example script, assuming no problems with port 5900 being
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taken on the local or remote sides, looks like:
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#!/bin/sh
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# usage: x11vnc_ssh <host>:<xdisplay>
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# e.g.: x11vnc_ssh snoopy.peanuts.com:0
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host=`echo $1 | awk -F: '{print $1}'`
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disp=`echo $1 | awk -F: '{print $2}'`
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if [ "x$disp" = "x" ]; then disp=0; fi
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cmd="x11vnc -display :$disp -localhost -rfbauth .vnc/passwd"
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enc="copyrect tight zrle hextile zlib corre rre raw"
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ssh -f -L 5900:localhost:5900 $host "$cmd"
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for i in 1 2 3
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do
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sleep 2
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if vncviewer -encodings "$enc" :0; then break; fi
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done
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See also rx11vnc.pl below.
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_________________________________________________________________
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#2. Another method is to start the VNC viewer in listen mode
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"vncviewer -listen" and have x11vnc initiate a reverse connection
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using the [24]-connect option:
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#!/bin/sh
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# usage: x11vnc_ssh <host>:<xdisplay>
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# e.g.: x11vnc_ssh snoopy.peanuts.com:0
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host=`echo $1 | awk -F: '{print $1}'`
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disp=`echo $1 | awk -F: '{print $2}'`
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if [ "x$disp" = "x" ]; then disp=0; fi
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cmd="x11vnc -display :$disp -localhost -connect localhost" # <== note new opt
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ion
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enc="copyrect tight zrle hextile zlib corre rre raw"
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vncviewer -encodings "$enc" -listen &
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pid=$!
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ssh -R 5500:localhost:5500 $host "$cmd"
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kill $pid
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Note the use of the ssh option -R instead of -L to set up a remote
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port redirection.
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_________________________________________________________________
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#3. A third way is specific to the TightVNC vncviewer special option
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-via for gateways. The only tricky part is we need to start up x11vnc
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and give it some time (5 seconds in this example) to start listening
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for connections (so we cannot use the TightVNC default setting for
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VNC_VIA_CMD):
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#!/bin/sh
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# usage: x11vnc_ssh <host>:<xdisplay>
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# e.g.: x11vnc_ssh snoopy.peanuts.com:0
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host=`echo $1 | awk -F: '{print $1}'`
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disp=`echo $1 | awk -F: '{print $2}'`
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if [ "x$disp" = "x" ]; then disp=0; fi
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VNC_VIA_CMD="ssh -f -L %L:%H:%R %G x11vnc -localhost -rfbport 5900 -display :$d
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isp; sleep 5"
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export VNC_VIA_CMD
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vncviewer -via $host localhost:0 # must be TightVNC vncviewer.
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Of course if you already have the x11vnc running waiting for
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connections (or have it started out of [25]inetd(1)), you can simply
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use the TightVNC "vncviewer -via gateway host:port" in its default
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mode to provide secure ssh tunnelling.
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VNC password file: Also note in the #1. example script that the
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[26]option "-rfbauth .vnc/passwd" provides additional protection by
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requiring a VNC password for every VNC viewer that connects. The
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vncpasswd or storepasswd programs, or the x11vnc [27]-storepasswd
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option can be used to create the password file. x11vnc also has the
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slightly less secure [28]-passwdfile and "-passwd XXXXX" [29]options
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to specify passwords.
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Important: It is up to you to tell x11vnc to use password protection,
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it will not do it for you automatically or force you to. The same goes
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for encrypting the channel between the viewer and x11vnc: it is up to
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you to use ssh, stunnel, VPN, etc. Also look into the -allow and
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-localhost [30]options and building x11vnc with [31]tcp_wrappers
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support to limit host access.
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_________________________________________________________________
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Downloading x11vnc:
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x11vnc is a contributed program to the [32]LibVNCServer project at
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SourceForge.net. I use libvncserver for all of the VNC aspects; I
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couldn't have done without it. The full source code may be found and
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downloaded (either file-release tarball or CVS tree) from the above
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link. As of Feb 2005, the [33]x11vnc-0.7.1.tar.gz source package is
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released (recommended download) . The [34]x11vnc 0.7.1 release notes.
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The x11vnc package is the subset of the libvncserver package needed to
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build the x11vnc program. Also, you can get a copy of my latest,
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bleeding edge [35]x11vnc.c file to replace the one in the above
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packages or the one in the CVS tree and then rebuild. You can also
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update the tcl/tk gui with the [36]tkx11vnc.h file. If you have an
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older libvncserver source tree, you may need to switch on the OLD_TREE
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variable near the top of the x11vnc.c file.
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See the [37]FAQ below for information about where you might obtain a
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precompiled x11vnc binary from 3rd parties.
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To obtain VNC viewers for the viewing side (Windows, Mac OS, or Unix)
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try these links:
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* [38]http://www.tightvnc.com/download.html
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* [39]http://www.realvnc.com/download-free.html
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* [40]http://sourceforge.net/projects/cotvnc/
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More tools: Here is a rsh/ssh wrapper script rx11vnc that attempts to
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automatically do the above Steps 1-3 for you (provided you have
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rsh/ssh login permission on the machine x11vnc is to be run on). The
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above example would be: "rx11vnc far-away.east:0" typed into a shell
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on sitting-here.west. Also included is an experimental script
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rx11vnc.pl that attempts to tunnel the vnc traffic through an ssh port
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redirection (and does not assume port 5900 is free). Have a look at
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them to see what they do and customize as needed:
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* [41]rx11vnc wrapper script
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* [42]rx11vnc.pl wrapper script to tunnel traffic thru ssh
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_________________________________________________________________
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Building x11vnc:
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If your OS has libjpeg.so and libz.so in standard locations you can
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build as follows (example given for the 0.7.1 release of x11vnc:
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replace with the version you downloaded):
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(un-tar the x11vnc+libvncserver tarball)
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# gzip -dc x11vnc-0.7.1.tar.gz | tar -xvf -
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(cd to the source directory)
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# cd x11vnc-0.7.1
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(run configure and then run make)
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# ./configure
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# make
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(if all went OK, copy x11vnc to the desired destination, e.g. $HOME/bin)
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# cp ./x11vnc/x11vnc $HOME/bin
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Or do make install, it will probably install to /usr/local/bin (run
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./configure --help for information on customizing your configuration).
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You can now run it via typing "x11vnc", "x11vnc -help", "x11vnc -nap
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-display :0", etc.
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Note: Currently gcc is required to build libvncserver. In some cases
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it will build with non-gcc compilers, but the resulting binary often
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fails to run properly. For Solaris pre-built gcc binaries are at
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[43]http://www.sunfreeware.com/ However, one user reports it does
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work fine when built with Sun Studio 10, so YMMV.
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_________________________________________________________________
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Building on Solaris, FreeBSD, etc: Depending on your version of
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Solaris or other Unix OS the jpeg and/or zlib libraries may be in
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non-standard places (e.g. /usr/local, /usr/sfw, /opt/sfw, etc).
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Note: If configure cannot find these two libraries then TightVNC and
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ZRLE encoding support will be disabled, and you don't want that! The
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TightVNC encoding gives very good compression and performance, it even
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makes a noticeable difference over a fast LAN.
|
|
|
|
|
|
|
|
|
Shortcuts: On Solaris 10 you can pick up almost everything just by
|
|
|
insuring that your PATH has /usr/sfw/bin (for gcc) and /usr/ccs/bin
|
|
|
(for other build tools), e.g.:
|
|
|
env PATH=/usr/sfw/bin:/usr/ccs/bin:$PATH sh -c './configure; make'
|
|
|
|
|
|
(The only this misses is /usr/X11/lib/libXrandr.so.2, which is for the
|
|
|
little used -xrandr option, see the script below to add it).
|
|
|
|
|
|
libjpeg is included in Solaris 9 and later (/usr/sfw/include and
|
|
|
/usr/sfw/lib), and zlib in Solaris 8 and later (/usr/include and
|
|
|
/usr/lib). So on Solaris 9 you can pick up everything with something
|
|
|
like this:
|
|
|
env PATH=/usr/local/bin:/usr/ccs/bin:$PATH CPPFLAGS='-I /usr/sfw/include' LDF
|
|
|
LAGS='-L/usr/sfw/lib -R/usr/sfw/lib' sh -c './configure; make'
|
|
|
|
|
|
assuming your gcc is in /usr/local/bin. Or starting with the 0.7.1
|
|
|
x11vnc release:
|
|
|
env PATH=/usr/local/bin:/usr/ccs/bin:$PATH sh -c './configure --with-jpeg=/us
|
|
|
r/sfw; make'
|
|
|
|
|
|
These are getting pretty long, see those assignments split up in the
|
|
|
build script below.
|
|
|
|
|
|
|
|
|
If your system does not have these libraries at all you can get the
|
|
|
source for the libraries to build them: libjpeg is available at
|
|
|
[44]ftp://ftp.uu.net/graphics/jpeg/ and zlib at
|
|
|
[45]http://www.gzip.org/zlib/. See also
|
|
|
[46]http://www.sunfreeware.com/ for Solaris binary packages of these
|
|
|
libraries as well as for gcc. Normally they will install into
|
|
|
/usr/local but you can install them anywhere with the
|
|
|
--prefix=/path/to/anywhere, etc.
|
|
|
|
|
|
|
|
|
Here is a build script that indicates one way to pass the library
|
|
|
locations information to the libvncserver configuration via the
|
|
|
CPPFLAGS and LDFLAGS environmental variables.
|
|
|
#!/bin/sh
|
|
|
|
|
|
# Build script for Solaris, etc, with gcc, libjpeg and libz in
|
|
|
# non-standard locations.
|
|
|
|
|
|
# set to get your gcc, etc:
|
|
|
PATH=/path/to/gcc/bin:/usr/ccs/bin:/usr/sfw/bin:$PATH
|
|
|
|
|
|
JPEG=/path/to/jpeg # set to maybe "/usr/local", "/usr/sfw", or "/opt/sfw"
|
|
|
ZLIB=/path/to/zlib # set to maybe "/usr/local", "/usr/sfw", or "/opt/sfw"
|
|
|
|
|
|
# Below we assume headers in $JPEG/include and $ZLIB/include and the
|
|
|
# shared libraries are in $JPEG/lib and $ZLIB/lib. If your situation
|
|
|
# is different change the locations in the two lines below.
|
|
|
|
|
|
CPPFLAGS="-I $JPEG/include -I $ZLIB/include"
|
|
|
LDFLAGS="-L $JPEG/lib -R $JPEG/lib -L $ZLIB/lib -R $ZLIB/lib"
|
|
|
|
|
|
# These two lines may not be needed on more recent Solaris releases:
|
|
|
CPPFLAGS="$CPPFLAGS -I /usr/openwin/include"
|
|
|
LDFLAGS="$LDFLAGS -L /usr/openwin/lib -R /usr/openwin/lib"
|
|
|
|
|
|
# These are for libXrandr.so on Solaris 10:
|
|
|
CPPFLAGS="$CPPFLAGS -I /usr/X11/include"
|
|
|
LDFLAGS="$LDFLAGS -L /usr/X11/lib -R /usr/X11/lib"
|
|
|
|
|
|
# Everything needs to built with _REENTRANT for thread safe errno:
|
|
|
CPPFLAGS="$CPPFLAGS -D_REENTRANT"
|
|
|
|
|
|
export PATH CPPFLAGS LDFLAGS
|
|
|
|
|
|
./configure
|
|
|
make
|
|
|
|
|
|
ls -l ./x11vnc/x11vnc
|
|
|
|
|
|
Then do make install or copy the x11vnc binary to your desired
|
|
|
destination.
|
|
|
|
|
|
BTW, To run a shell script, just cut-and-paste the above into a file,
|
|
|
say "myscript", then modify the "/path/to/..." items to correspond to
|
|
|
your system/environment, and then type: "sh myscript" to run it.
|
|
|
|
|
|
Note that on Solaris make is /usr/ccs/bin/make, so that is why the
|
|
|
above puts /usr/ccs/bin in PATH. Other important build utilities are
|
|
|
there too: ld, ar, etc. Also, it is probably a bad idea to have
|
|
|
/usr/ucb in your PATH while building.
|
|
|
|
|
|
Starting with the 0.7.1 x11vnc release the "configure --with-jpeg=DIR
|
|
|
--with-zlib=DIR" options are handy if you want to avoid making a
|
|
|
script.
|
|
|
|
|
|
One user had a problem where the above build script was failing
|
|
|
because his work environment had the ENV variable set to a script that
|
|
|
was resetting his PATH so that gcc could no longer be found. Make sure
|
|
|
you do not have any ENV or BASH_ENV in your environment doing things
|
|
|
like that.
|
|
|
|
|
|
If you need to build on Solaris 2.5.1 or earlier or other older Unix
|
|
|
OS's, see [47]this workaround FAQ.
|
|
|
|
|
|
Building on FreeBSD, OpenBSD, ...: The jpeg libraries seem to be in
|
|
|
/usr/local or /usr/pkg on these OS's. You won't need the openwin stuff
|
|
|
in the above script (but you may need /usr/X11R6/...). Also starting
|
|
|
with the 0.7.1 x11vnc release, this usually works:
|
|
|
./configure --with-jpeg=/usr/local
|
|
|
make
|
|
|
|
|
|
Building on HP-UX: For jpeg and zlib you will need to do the same
|
|
|
sort of thing as described above for Solaris. You set CPPFLAGS and
|
|
|
LDFLAGS to find them (see below for an example). You do not need to do
|
|
|
any of the above /usr/openwin stuff. Also, HP-UX does not seem to
|
|
|
support -R, so get rid of the -R items in LDFLAGS. Because of this, at
|
|
|
runtime you may need to set LD_LIBRARY_PATH or SHLIB_PATH to indicate
|
|
|
the directory paths so the libraries can be found. It is a good idea
|
|
|
to have static archives, e.g. libz.a and libjpeg.a for the nonstandard
|
|
|
libraries so that they get bolted into the x11vnc binary.
|
|
|
|
|
|
Finally, there seems to be a bug with gcc on HP-UX 11.xx: something
|
|
|
fails (in the gcc private header files?) and it thinks it cannot find
|
|
|
gettimeofday(). As a workaround add this to CPPFLAGS:
|
|
|
-DLIBVNCSERVER_HAVE_GETTIMEOFDAY=1. You may get some warnings but we
|
|
|
have verified that this generates working x11vnc binaries on HP-UX
|
|
|
hppa and ia64.
|
|
|
|
|
|
Here is what we recently did to build x11vnc 0.7.1 on HP-UX 11.11
|
|
|
env CPPFLAGS="-DLIBVNCSERVER_HAVE_GETTIMEOFDAY=1 -I $HOME/hpux/jpeg/include -I
|
|
|
$HOME/hpux/zlib/include" LDFLAGS="-L $HOME/hpux/jpeg/lib -L $HOME/hpux/zlib/lib
|
|
|
" ./configure
|
|
|
make
|
|
|
|
|
|
Where we had static archives (libjpeg.a, libz.a) only in the
|
|
|
$HOME/hpux/... directories.
|
|
|
_________________________________________________________________
|
|
|
|
|
|
Some Notes:
|
|
|
|
|
|
Network performance: Whether you are using Xvnc or x11vnc it is
|
|
|
always a good idea to have a solid background color instead of a
|
|
|
pretty background image. Each and every re-exposure of the background
|
|
|
must be resent over the network: better to have that background be a
|
|
|
solid color that compresses very well compared to a photo image. (This
|
|
|
is one place where the X protocol has an advantage over the VNC
|
|
|
protocol.) I suggest using xsetroot, dtstyle or similar utility to set
|
|
|
a solid background while using x11vnc. You can turn the pretty
|
|
|
background image back on when you are using the display directly.
|
|
|
Update: As of Feb/2005 in the libvncserver CVS, x11vnc has the
|
|
|
[48]-solid [color] option that works on recent GNOME, KDE, and CDE and
|
|
|
also on classic X (background image is on the root window).
|
|
|
|
|
|
I also find the [49]TightVNC encoding gives the best response for my
|
|
|
usage (Unix <-> Unix over cable modem). One needs a tightvnc-aware
|
|
|
vncviewer to take advantage of this encoding.
|
|
|
|
|
|
TCP port issues: Notice the lines
|
|
|
18/07/2003 14:36:31 Autoprobing selected port 5900
|
|
|
PORT=5900
|
|
|
|
|
|
in the output. 5900 is the default VNC listening port (just like 6000
|
|
|
is X11's default listening port). Had port 5900 been taken by some
|
|
|
other application, x11vnc would have next tried 5901. That would mean
|
|
|
the viewer command above should be changed to vncviewer
|
|
|
far-away.east:1. You can force the issue with the "[50]-rfbport NNNN"
|
|
|
option where NNNN is the desired port number. If that port is already
|
|
|
taken, x11vnc will exit immediately. (also see the "SunRay Gotcha"
|
|
|
note below)
|
|
|
|
|
|
Options: x11vnc has (far too) many features that may be activated
|
|
|
via its [51]command line options. Useful options are -nap to use fewer
|
|
|
resources (it sleeps more between polls when activity is low) and
|
|
|
-rfbauth passwd-file to use VNC password protection (the vncpasswd or
|
|
|
storepasswd programs, or the x11vnc [52]-storepasswd option can be
|
|
|
used to create the password file).
|
|
|
|
|
|
Algorithm: How does x11vnc do it? Rather brute-forcedly: it
|
|
|
continuously polls the X11 framebuffer for changes using
|
|
|
XShmGetImage(). When changes are discovered, it instructs libvncserver
|
|
|
which rectangular regions of the framebuffer have changed, and
|
|
|
libvncserver compresses the changes and sends them off to any
|
|
|
connected VNC viewers. A number of applications do similar things,
|
|
|
such as x0rfbserver, krfb, x0vncserver. x11vnc uses a 32 x 32 pixel
|
|
|
tile model (the desktop is decomposed into roughly 1000 such tiles),
|
|
|
where changed tiles are found by pseudo-randomly polling 1 pixel tall
|
|
|
horizontal scanlines. This is a surprisingly effective algorithm for
|
|
|
finding changed regions. For keyboard and mouse user input the XTEST
|
|
|
extension is used to pass the input events to the X server. To detect
|
|
|
XBell "beeps" the XKEYBOARD extension is used. If available, the
|
|
|
XFIXES extension is used to retrieve the current mouse cursor shape.
|
|
|
|
|
|
Barbershop mirrors effect: What if x11vnc is started up, and
|
|
|
vncviewer is then started up on the same machine and displayed on the
|
|
|
same display x11vnc is polling? One might "accidentally" do this when
|
|
|
first testing out the programs. You get an interesting "feedback"
|
|
|
effect where vncviewer images keep popping up each one contained in
|
|
|
the previous one and slightly shifted a bit by the window manager
|
|
|
decorations. There will be an [53]even more interesting effect if
|
|
|
-scale is used. Also, if the XKEYBOARD is supported and the XBell
|
|
|
"beeps" once, you get an infinite loop of beeps going off. Although
|
|
|
all of this is mildly exciting it is not much use: you will normally
|
|
|
run and display the viewer on a different machine!
|
|
|
|
|
|
SunRay notes: You can run x11vnc on your (connected or disconnected)
|
|
|
[54]SunRay session (Please remember to use [55]-nap and maybe
|
|
|
[56]-wait 200 to avoid being a resource hog! It also helps to have a
|
|
|
solid background color). You have to know the name of the machine your
|
|
|
SunRay session X server is running on. You also need to know the X11
|
|
|
DISPLAY number for the session: on a SunRay it could be a large
|
|
|
number, e.g. :137, since there are many people with X sessions (Xsun
|
|
|
processes) on the same machine. If you don't know it, you can get it
|
|
|
by running who(1) in a shell on the SunRay server and looking for the
|
|
|
dtlocal entry with your username (and if you don't even know which
|
|
|
server machine has your session, you could login to all possible ones
|
|
|
looking at the who output for your username...).
|
|
|
|
|
|
I put some code in my ~/.xsession script that stores $DISPLAY in my
|
|
|
~/.sunray_current file at session startup and deletes it when the
|
|
|
session ends to make it easy to get at the hostname and X11 display
|
|
|
number info for my current X sessions.
|
|
|
|
|
|
SunRay Gotcha #1: Note that even though your SunRay X11 DISPLAY is
|
|
|
something like :137, x11vnc still tries for port 5900 as its listening
|
|
|
port if it can get it, in which case the VNC display (i.e. the
|
|
|
information you supply to the VNC viewer) is something like
|
|
|
sunray-server:0 (note the :0 corresponding to port 5900, it is not
|
|
|
:137). If it cannot get 5900, it tries for 5901, and so on. You can
|
|
|
also try to force the port (and thereby the VNC display) using the
|
|
|
[57]-rfbport NNNN option.
|
|
|
|
|
|
SunRay Gotcha #2: If you get an error like:
|
|
|
shmget(tile) failed.
|
|
|
shmget: No space left on device
|
|
|
|
|
|
when starting up x11vnc that most likely means all the shared memory
|
|
|
(shm) slots are filled up on your machine. The Solaris default is only
|
|
|
100, and that can get filled up in a week or so on a SunRay server
|
|
|
with lots of users. If the shm slot is orphaned (e.g. creator process
|
|
|
dies) the slot is not reclaimed. You can view the shm slots with the
|
|
|
"ipcs -mA" command. If there are about 100 then you've probably hit
|
|
|
this problem. They can be cleaned out (by the owner or by root) using
|
|
|
the ipcrm command. I wrote a script [58]shm_clear that finds the
|
|
|
orphans and lists or removes them. Longer term, have your SunRay
|
|
|
sysadmin add something like this to /etc/system:
|
|
|
set shmsys:shminfo_shmmax = 0x2000000
|
|
|
set shmsys:shminfo_shmmni = 0x1000
|
|
|
|
|
|
Limitations:
|
|
|
|
|
|
* Due to the polling nature, some activities (opaque window moves,
|
|
|
scrolling), can be pretty choppy/ragged and others (exposures of
|
|
|
large areas) slow. Experiment with interacting a bit differently
|
|
|
than you normally do to minimize the effects (e.g. do fullpage
|
|
|
paging rather than line-by-line scrolling, and move windows in a
|
|
|
single, quick motion). Work is in progress to attempt to speed
|
|
|
things up using the copyrect encoding and other things, but they
|
|
|
will likely only speed up certain activities, not all.
|
|
|
* A rate limiting factor for x11vnc performance is that video
|
|
|
hardware is optimized for writing, not reading (x11vnc reads the
|
|
|
video framebuffer for the screen image data). The difference can
|
|
|
be a factor of 10 to 1000, and so it usually takes about 0.5-1 sec
|
|
|
to read in the whole video hardware framebuffer (e.g. 5MB for
|
|
|
1280x1024 at depth 24). So whenever activity changes most of the
|
|
|
screen (e.g. moving a large window) there is a delay of 0.5-1 sec
|
|
|
while x11vnc reads the changed regions in.
|
|
|
To get a sense of the read and write speeds of your video card,
|
|
|
you can run the benchmarks like: x11perf -getimage500, x11perf
|
|
|
-putimage500, x11perf -shmput500 and for XFree86 displays with
|
|
|
direct graphics access the dga command (press "b" to run the
|
|
|
benchmark and then after a few seconds press "q" to quit).
|
|
|
On XFree86 it is actually possible to increase the framebuffer
|
|
|
read speed considerably (5-100 times) by using the Shadow
|
|
|
Framebuffer (a copy of the framebuffer is kept in main memory and
|
|
|
this can be read much more quickly). To do this one puts the line
|
|
|
Option "ShadowFB" "true" (and depending on video card driver,
|
|
|
Option "NoAccel" "true" may be needed too) in the Device section
|
|
|
of the /etc/X11/XF86Config file. Note that this disables 2D
|
|
|
acceleration at the physical display and so likely defeats the
|
|
|
purpose. Nevertheless this could be handy in some circumstances,
|
|
|
e.g. if the slower speed while sitting at the physical display was
|
|
|
acceptable (this seems to be true for most video cards these
|
|
|
days). Unfortunately it does not seem shadowfb can be turned on
|
|
|
and off dynamically...
|
|
|
* Somewhat surprisingly, the X11 mouse (cursor) shape is write-only
|
|
|
and cannot be queried from the X server. So in x11vnc the cursor
|
|
|
shape stays fixed at an arrow. (see the "-cursor X" and "-cursor
|
|
|
some" [59]options, however, for a partial hack for the root
|
|
|
window, etc.). Also, on Solaris using the SUN_OVL overlay
|
|
|
extension, x11vnc can show the correct mouse cursor when the
|
|
|
[60]-overlay option is also supplied. A similar thing is done on
|
|
|
IRIX as well when -overlay is supplied. As of Dec/2004 x11vnc
|
|
|
supports the XFIXES extension (in Xorg and Solaris 10) to query
|
|
|
the X server for the exact cursor shape, this works pretty well
|
|
|
except that cursors with transparency (alpha channel) need to
|
|
|
approximated to solid RGB values.
|
|
|
* Audio from applications is of course not redirected (separate
|
|
|
redirectors do exist, e.g. esd). The XBell() "beeps" will work if
|
|
|
the X server supports the XKEYBOARD extension. (Note that on
|
|
|
Solaris XKEYBOARD is disabled by default. Passing +kb to Xsun
|
|
|
enables it).
|
|
|
* Occasionally a patch of tiles will not get updated correctly.
|
|
|
Evidently a timing related bug and difficult to reproduce...
|
|
|
* Using -threads can expose some bugs in libvncserver.
|
|
|
|
|
|
Please feel free to [61]contact me if you have any questions,
|
|
|
problems, or comments about x11vnc, etc.
|
|
|
Also, some people ask if they can make a donation, see [62]this link
|
|
|
for that.
|
|
|
_________________________________________________________________
|
|
|
|
|
|
x11vnc FAQ:
|
|
|
|
|
|
|
|
|
[Building and Starting]
|
|
|
|
|
|
[63]Q-1: I can't get x11vnc to start up. It says "XOpenDisplay failed
|
|
|
(null)" or "Xlib: connection to ":0.0" refused by server" and then
|
|
|
exits. What do I need to do?
|
|
|
|
|
|
[64]Q-2: I can't get x11vnc and/or libvncserver to compile.
|
|
|
|
|
|
[65]Q-3: Help, I need to run x11vnc on Solaris 2.5.1 (or other old
|
|
|
Unix/Linux) and it doesn't compile!
|
|
|
|
|
|
[66]Q-4: Where can I get a precompiled x11vnc binary for my Operating
|
|
|
System?
|
|
|
|
|
|
[67]Q-5: Where can I get a VNC Viewer binary (or source code) for the
|
|
|
Operating System I will be viewing from?
|
|
|
|
|
|
[68]Q-6: How can I see all of x11vnc's command line options and
|
|
|
documentation on how to use them?
|
|
|
|
|
|
[69]Q-7: I don't like typing arcane command line options every time I
|
|
|
start x11vnc. What can I do? Is there a config file? Or a GUI?
|
|
|
|
|
|
[70]Q-8: Can I make x11vnc more quiet and also go into the background
|
|
|
after starting up?
|
|
|
|
|
|
[71]Q-9: Sometimes when a VNC viewer dies abruptly, x11vnc also dies
|
|
|
with the error message like: "Broken pipe". I'm using the -forever
|
|
|
mode and I want x11vnc to keep running.
|
|
|
|
|
|
[Win2VNC Related]
|
|
|
|
|
|
[72]Q-10: I have two separate machine displays in front of me, one
|
|
|
Windows the other X11: can I use x11vnc in combination with Win2VNC in
|
|
|
dual-screen mode to pass the keystrokes and mouse motions to the X11
|
|
|
display?
|
|
|
|
|
|
[73]Q-11: I am running Win2VNC on my Windows machine and I'm trying to
|
|
|
create a dual-screen mode with my second display monitor by running
|
|
|
"x11vnc -nofb". Whenever I initiate the connection Win2VNC quickly
|
|
|
disconnects and x11vnc says something like:
|
|
|
rfbProcessClientNormalMessage: read: Connection reset by peer
|
|
|
|
|
|
[Color Issues]
|
|
|
|
|
|
[74]Q-12: The X display I run x11vnc on is only 8 bits per pixel (bpp)
|
|
|
PseudoColor (i.e. only 256 distinct colors). The x11vnc colors may
|
|
|
start out OK, but after a while the colors are incorrect in certain
|
|
|
windows.
|
|
|
|
|
|
[75]Q-13: Color problems: Why are the colors for some windows messed
|
|
|
up in x11vnc? BTW, I have an X display that has nice
|
|
|
overlay/multi-depth visuals of different color depths: e.g. there are
|
|
|
both depth 8 and 24 visuals available at the same time.
|
|
|
|
|
|
[76]Q-14: How do I figure out the window id to supply to the -id
|
|
|
windowid option?
|
|
|
|
|
|
[77]Q-15: Why don't menus or other transient windows come up when I am
|
|
|
using the -id windowid option to view a single application window?
|
|
|
|
|
|
[78]Q-16: My X display is depth 24 at 24bpp (instead of the normal
|
|
|
depth 24 at 32bpp). I'm having lots of color and visual problems with
|
|
|
x11vnc and/or vncviewer. What's up?
|
|
|
|
|
|
[Xterminals]
|
|
|
|
|
|
[79]Q-17: Can I use x11vnc to view and interact with an Xterminal
|
|
|
(e.g. NCD) that is not running UNIX and so x11vnc cannot be run on it
|
|
|
directly?
|
|
|
|
|
|
[80]Q-18: How do I get my X permissions (MIT-MAGIC-COOKIE) correct for
|
|
|
a Unix/Linux machine acting as an Xterminal?
|
|
|
|
|
|
[Remote Control]
|
|
|
|
|
|
[81]Q-19: How do I stop x11vnc once it is running in the background?
|
|
|
|
|
|
[82]Q-20: Can I change settings in x11vnc without having to restart
|
|
|
it? I.e., is there a way to remote control it?
|
|
|
|
|
|
[Security and Permissions]
|
|
|
|
|
|
[83]Q-21: How do I create a VNC password for use with x11vnc?
|
|
|
|
|
|
[84]Q-22: Can I have two passwords for VNC viewers, one for full
|
|
|
access and the other for view-only access to the display?
|
|
|
|
|
|
[85]Q-23: Can I fine tune what types of user input are allowed? E.g.
|
|
|
have some users just be able to move the mouse, but not click or type
|
|
|
anything?
|
|
|
|
|
|
[86]Q-24: Why does x11vnc exit as soon as the VNC viewer disconnects?
|
|
|
And why doesn't it allow more than one VNC viewer to connect at the
|
|
|
same time?
|
|
|
|
|
|
[87]Q-25: Can I limit which machines incoming VNC clients can connect
|
|
|
from?
|
|
|
|
|
|
[88]Q-26: How do I build x11vnc/libvncserver with libwrap
|
|
|
(tcp_wrappers) support?
|
|
|
|
|
|
[89]Q-27: Can I have x11vnc only listen on one network interface (e.g.
|
|
|
internal LAN) rather than having it listen on all network interfaces
|
|
|
and relying on -allow to filter unwanted connections out?
|
|
|
|
|
|
[90]Q-28: Now that -localhost implies listening only on the loopback
|
|
|
interface, how I can occasionally allow in a non-local host via the
|
|
|
allowonce remote control command?
|
|
|
|
|
|
[91]Q-29: How can I tunnel my connection to x11vnc via an encrypted
|
|
|
SSH channel between two Unix machines?
|
|
|
|
|
|
[92]Q-30: How can I tunnel my connection to x11vnc via an encrypted
|
|
|
SSH channel from Windows using an SSH client like Putty?
|
|
|
|
|
|
[93]Q-31: Can I prompt the user at the local X display whether the
|
|
|
incoming VNC client should be accepted or not? Can I decide to make
|
|
|
some clients view-only? How about running an arbitrary program to make
|
|
|
the decisions?
|
|
|
|
|
|
[94]Q-32: Does x11vnc support Unix usernames and passwords? Can I
|
|
|
further limit the set of Unix usernames who can connect to the VNC
|
|
|
desktop?
|
|
|
|
|
|
[95]Q-33: I start x11vnc as root because it is launched via inetd(1)
|
|
|
or a display manager like gdm(1). Can I have x11vnc later switch to a
|
|
|
different user?
|
|
|
|
|
|
[96]Q-34: I use a screen-lock when I leave my workstation (e.g.
|
|
|
xscreensaver or xlock). When I remotely access my workstation desktop
|
|
|
via x11vnc I can unlock the desktop fine, but I am worried people will
|
|
|
see my activities on the physical monitor. What can I do to prevent
|
|
|
this, or at least make it more difficult?
|
|
|
|
|
|
[97]Q-35: Can I have x11vnc automatically lock the screen when I
|
|
|
disconnect the VNC viewer?
|
|
|
|
|
|
[Display Managers and Services]
|
|
|
|
|
|
[98]Q-36: How can I run x11vnc as a "service" that is always
|
|
|
available?
|
|
|
|
|
|
[99]Q-37: How can I use x11vnc to connect to an X login screen like
|
|
|
xdm, GNOME gdm, KDE kdm, or CDE dtlogin? (i.e. nobody is logged into
|
|
|
an X session yet).
|
|
|
|
|
|
[100]Q-38: Can I run x11vnc out of inetd(1)? How about xinetd(1)?
|
|
|
|
|
|
[101]Q-39: How do I make x11vnc work with the Java VNC viewer applet
|
|
|
in a web browser?
|
|
|
|
|
|
[102]Q-40: Are reverse connections (i.e. the VNC server connecting to
|
|
|
the VNC viewer) using "vncviewer -listen" and vncconnect(1) supported?
|
|
|
|
|
|
[Resource Usage and Performance]
|
|
|
|
|
|
[103]Q-41: I have lots of memory, but why does x11vnc fail with
|
|
|
shmget: No space left on device or Minor opcode of failed
|
|
|
request: 1 (X_ShmAttach)?
|
|
|
|
|
|
[104]Q-42: How can I make x11vnc use less system resources?
|
|
|
|
|
|
[105]Q-43: How can I make x11vnc use MORE system resources?
|
|
|
|
|
|
[106]Q-44: I use x11vnc over a slow link with high latency (e.g.
|
|
|
dialup modem), is there anything I can do to speed things up?
|
|
|
|
|
|
[107]Q-45: When I drag windows around with the mouse or scroll up and
|
|
|
down things really bog down (unless I do the drag in a single, quick
|
|
|
motion). Is there anything to do to improve things?
|
|
|
|
|
|
[108]Q-46: Does x11vnc support the X DAMAGE Xserver extension to find
|
|
|
modified regions of the screen quickly and efficiently?
|
|
|
|
|
|
[Mouse Cursor Shapes]
|
|
|
|
|
|
[109]Q-47: Why isn't the mouse cursor shape (the little icon shape
|
|
|
where the mouse pointer is) correct as I move from window to window?
|
|
|
|
|
|
[110]Q-48: When using XFIXES cursorshape mode, some of the cursors
|
|
|
look really bad with extra black borders around the cursor and other
|
|
|
cruft. How can I improve their appearance?
|
|
|
|
|
|
[111]Q-49: In XFIXES mode, are there any hacks to handle cursor
|
|
|
transparency ("alpha channel") exactly?
|
|
|
|
|
|
[Mouse Pointer]
|
|
|
|
|
|
[112]Q-50: Why does the mouse arrow just stay in one corner in my
|
|
|
vncviewer, whereas my cursor (that does move) is just a dot?
|
|
|
|
|
|
[113]Q-51: Can I take advantage of the TightVNC extension to the VNC
|
|
|
protocol where Cursor Positions Updates are sent back to all connected
|
|
|
clients (i.e. passive viewers can see the mouse cursor being moved
|
|
|
around by another viewer)?
|
|
|
|
|
|
[114]Q-52: Is it possible to swap the mouse buttons (e.g. left-handed
|
|
|
operation), or arbitrarily remap them? How about mapping button clicks
|
|
|
to keystrokes, e.g. to partially emulate Mouse wheel scrolling?
|
|
|
|
|
|
[Keyboard Issues]
|
|
|
|
|
|
[115]Q-53: How can I get my AltGr and Shift modifiers to work between
|
|
|
keyboards for different languages?
|
|
|
|
|
|
[116]Q-54: When I try to type a "<" (i.e. less than) instead I get ">"
|
|
|
(i.e. greater than)! Strangely, typing ">" works OK!!
|
|
|
|
|
|
[117]Q-55: I'm using an "international" keyboard (e.g. German "de", or
|
|
|
Danish "dk") and the -modtweak mode works well if the VNC viewer is
|
|
|
run on a Unix/Linux machine with a similar keyboard. But if I run the
|
|
|
VNC viewer on Unix/Linux with a different keyboard (e.g. "us") or
|
|
|
Windows with any keyboard, I can't type some keys like: "@", "$", "<",
|
|
|
">", etc. How can I fix this?
|
|
|
|
|
|
[118]Q-56: When typing I sometimes get double, triple, or more of my
|
|
|
keystrokes repeated. I'm sure I only typed them once, what can I do?
|
|
|
|
|
|
[119]Q-57: The x11vnc -norepeat mode is in effect, but I still get
|
|
|
repeated keystrokes!!
|
|
|
|
|
|
[120]Q-58: The machine where I run x11vnc has an AltGr key, but the
|
|
|
local machine where I run the VNC viewer does not. Is there a way I
|
|
|
can map a local unused key to send an AltGr? How about a Compose key
|
|
|
as well?
|
|
|
|
|
|
[121]Q-59: I have a Sun machine I run x11vnc on. Its Sun keyboard has
|
|
|
just one Alt key labelled "Alt" and two Meta keys labelled with little
|
|
|
diamonds. The machine where I run the VNC viewer only has Alt keys.
|
|
|
How can I send a Meta keypress? (e.g. emacs needs this)
|
|
|
|
|
|
[122]Q-60: Can I map a keystroke to a mouse button click on the remote
|
|
|
machine?
|
|
|
|
|
|
[Screen Related Issues and Features]
|
|
|
|
|
|
[123]Q-61: The remote display is larger (in number of pixels) than the
|
|
|
local display I am running the vncviewer on. I don't like the
|
|
|
vncviewer scrollbars, what I can do?
|
|
|
|
|
|
[124]Q-62: Does x11vnc support server-side framebuffer scaling? (E.g.
|
|
|
to make the desktop smaller).
|
|
|
|
|
|
[125]Q-63: Does x11vnc work with Xinerama? (i.e. multiple monitors
|
|
|
joined together to form one big, single screen).
|
|
|
|
|
|
[126]Q-64: Can I use x11vnc on a multi-headed display that is not
|
|
|
Xinerama (i.e. separate screens :0.0, :0.1, ... for each monitor)?
|
|
|
|
|
|
[127]Q-65: Can x11vnc show only a portion of the display? (E.g. for a
|
|
|
special purpose rfb application).
|
|
|
|
|
|
[128]Q-66: Does x11vnc support the XRANDR (X Resize, Rotate and
|
|
|
Reflection) extension? Whenever I rotate or resize the screen x11vnc
|
|
|
just seems to crash.
|
|
|
|
|
|
[129]Q-67: Why is the view in my VNC viewer completely black? Or why
|
|
|
is everything flashing around randomly?
|
|
|
|
|
|
[130]Q-68: I use Linux Virtual Consoles (VC's) to implement 'Fast User
|
|
|
Switching' between users' sessions (e.g. Betty is on Ctrl-Alt-F7,
|
|
|
Bobby is on Ctrl-Alt-F8, and Sid is on Ctrl-Alt-F1: they use those
|
|
|
keystrokes to switch between their sessions). How come the view in a
|
|
|
VNC viewer connecting to x11vnc is either completely black or
|
|
|
otherwise all messed up unless the X session x11vnc is attached to is
|
|
|
in the active VC?
|
|
|
|
|
|
[131]Q-69: I am using x11vnc where my local machine has "popup/hidden
|
|
|
taskbars" (e.g. GNOME or MacOS X) and the remote display where x11vnc
|
|
|
runs also has "popup/hidden taskbars" (e.g. GNOME). When I move the
|
|
|
mouse to the edge of the screen where the popups happen, the taskbars
|
|
|
interfere and fight with each other in strange ways. What can I do?
|
|
|
|
|
|
[Misc: Clipboard, Beeps, Thanks, etc.]
|
|
|
|
|
|
[132]Q-70: Does the Clipboard/Selection get transferred between the
|
|
|
vncviewer and the X display?
|
|
|
|
|
|
[133]Q-71: Why don't I hear the "Beeps" in my X session (e.g. when
|
|
|
typing tput bel in an xterm)?
|
|
|
|
|
|
[134]Q-72: Thanks for your program and for your help! Can I make a
|
|
|
donation?
|
|
|
_________________________________________________________________
|
|
|
|
|
|
|
|
|
[Building and Starting]
|
|
|
|
|
|
Q-1: I can't get x11vnc to start up. It says "XOpenDisplay failed
|
|
|
(null)" or "Xlib: connection to ":0.0" refused by server" and then
|
|
|
exits. What do I need to do?
|
|
|
|
|
|
For the former error, you need to specify the X display to connect to
|
|
|
(it also needs to be on the same machine x11vnc is to run on). Set
|
|
|
your DISPLAY environment variable or use the [135]-display option to
|
|
|
specify it. Nearly always the correct value will be ":0"
|
|
|
|
|
|
For the latter error, you need to set up the X11 permissions
|
|
|
correctly. See the xauth(1), Xsecurity(7), and xhost(1) man pages for
|
|
|
much info. For example, you may need to set your XAUTHORITY
|
|
|
environment variable or use the [136]-auth option to point to the
|
|
|
correct cookie file (e.g. /home/joe/.Xauthority or /var/gdm/:0.Xauth),
|
|
|
or simply be sure you run x11vnc as the correct user (i.e. the user
|
|
|
who owns the X session you wish to view). Running x11vnc as root is
|
|
|
not enough: you need to know where the XAUTHORITY file for the desired
|
|
|
X display is. Example:
|
|
|
x11vnc -display :0 -auth /var/gdm/:0.Xauth
|
|
|
|
|
|
Less safe, but to avoid figuring out where the XAUTHORITY file is, if
|
|
|
the person sitting at the X session types "xhost +localhost" then one
|
|
|
should be able to attach x11vnc to the session (from the same
|
|
|
machine). The person could then type "xhost -localhost" after x11vnc
|
|
|
has connected to go back to the default permissions. Also, for some
|
|
|
situations the -users lurk= option may be of use (please read the
|
|
|
documentation on the [137]-users option).
|
|
|
|
|
|
Some Linux distributions or display managers may set XAUTHORITY to a
|
|
|
random local filename. You need to dig out where they have hidden the
|
|
|
MIT-MAGIC-COOKIE file (and set XAUTHORITY to it or use the [138]-auth
|
|
|
option). This command is often useful to find non-standard settings
|
|
|
for XAUTHORITY:
|
|
|
ps wwwweaux | tr ' ' '\n' | grep XAUTHORITY | sort -u
|
|
|
|
|
|
To test out your X11 permissions, set DISPLAY and possibly XAUTHORITY
|
|
|
(see your shell's man page, bash(1), tcsh(1), on how to set
|
|
|
environment variables) and type xdpyinfo in the same place you will be
|
|
|
typing (or otherwise running) x11vnc. If information is printed out
|
|
|
about the X display (screen sizes, supported extensions, color visuals
|
|
|
info) that means the X11 permissions are set up properly: xdpyinfo
|
|
|
successfully connected to DISPLAY. You could also type xclock and make
|
|
|
sure no errors are reported (a clock should appear on the X display,
|
|
|
type Ctrl-C to quit it)
|
|
|
|
|
|
Important: if you cannot get your X11 permissions so that the xdpyinfo
|
|
|
or xclock tests work, x11vnc also will not work (all of these X
|
|
|
clients must be able to connect to the X server to function properly).
|
|
|
|
|
|
Q-2: I can't get x11vnc and/or libvncserver to compile.
|
|
|
|
|
|
Make sure you have all of the required -devel packages installed.
|
|
|
These include X11/XFree86, libjpeg, libz, ...
|
|
|
|
|
|
After running the libvncserver configure, carefully examine the output
|
|
|
and the messages in the config.log file looking for missing
|
|
|
components. If the configure output looks like:
|
|
|
checking how to run the C preprocessor... gcc -E
|
|
|
checking for X... no
|
|
|
checking for XkbSelectEvents in -lX11... no
|
|
|
checking for XineramaQueryScreens in -lXinerama... no
|
|
|
checking for XTestFakeKeyEvent in -lXtst... no
|
|
|
|
|
|
there is quite a bit wrong with the build environment. Hopefully
|
|
|
simply adding -devel packages will fix it.
|
|
|
|
|
|
For Debian the list seems to be:
|
|
|
gcc
|
|
|
make
|
|
|
libc6-dev
|
|
|
libjpeg62-dev
|
|
|
libx11-dev
|
|
|
libxext-dev
|
|
|
libxtst-dev
|
|
|
x-dev
|
|
|
xlibs-static-dev
|
|
|
zlib1g-dev
|
|
|
|
|
|
For Redhat the list seems to be:
|
|
|
gcc
|
|
|
make
|
|
|
glibc-devel
|
|
|
libjpeg-devel
|
|
|
XFree86-devel
|
|
|
zlib-devel
|
|
|
|
|
|
Q-3: Help, I need to run x11vnc on Solaris 2.5.1 (or other old
|
|
|
Unix/Linux) and it doesn't compile!
|
|
|
|
|
|
We apologize that x11vnc does not build cleanly on older versions of
|
|
|
Solaris, Linux, etc.: very few users are on these old releases.
|
|
|
|
|
|
We have heard that since Dec/2004 a Solaris 2.6 built x11vnc will run
|
|
|
on Solaris Solaris 2.5 and 2.5.1 (since a workaround for XConvertCase
|
|
|
is provided).
|
|
|
|
|
|
In any event, here is a workaround for Solaris 2.5.1 (and perhaps
|
|
|
earlier and perhaps non-Solaris):
|
|
|
|
|
|
First use the environment settings (CPPFLAGS, LDFLAGS, etc.) in the
|
|
|
above [139]Solaris build script to run the configure command. That
|
|
|
should succeed without failure. Then you have to hand edit the
|
|
|
autogenerated rfb/rfbconfig.h file in the source tree, and just before
|
|
|
the last #endif at the bottom of that file insert these workaround
|
|
|
lines:
|
|
|
struct timeval _tmp_usleep_tv;
|
|
|
#define usleep(x) \
|
|
|
_tmp_usleep_tv.tv_sec = (x) / 1000000; \
|
|
|
_tmp_usleep_tv.tv_usec = (x) % 1000000; \
|
|
|
select(0, NULL, NULL, NULL, &_tmp_usleep_tv);
|
|
|
int gethostname(char *name, int namelen);
|
|
|
long random();
|
|
|
int srandom(unsigned int seed);
|
|
|
#undef LIBVNCSERVER_HAVE_LIBPTHREAD
|
|
|
#ifndef SHUT_RDWR
|
|
|
#define SHUT_RDWR 2
|
|
|
#endif
|
|
|
#ifndef in_addr_t
|
|
|
typedef unsigned int in_addr_t;
|
|
|
#endif
|
|
|
#define snprintf(a, n, args...) sprintf((a), ## args)
|
|
|
|
|
|
Then run make with the Solaris build script environment, everything
|
|
|
should compile without problems, and the resulting x11vnc binary
|
|
|
should work OK. If some non-x11vnc related programs fail (e.g. test
|
|
|
programs) and the x11vnc binary is not created try "make -k" to have
|
|
|
it keep going. Similar sorts of kludges in rfb/rfbconfig.h can be done
|
|
|
on other older OS (Solaris, Linux, ...) releases.
|
|
|
|
|
|
Here are some notes for similar steps that need to be done to build on
|
|
|
[140]SunOS 4.x
|
|
|
|
|
|
Please let us know if you had to use the above workaround (and whether
|
|
|
it worked or not). If there is enough demand we will try to push clean
|
|
|
compilations back to earlier Solaris, Linux, etc, releases.
|
|
|
|
|
|
Q-4: Where can I get a precompiled x11vnc binary for my Operating
|
|
|
System?
|
|
|
|
|
|
Hopefully the [141]build steps above and [142]FAQ provide enough info
|
|
|
for a painless compile for most environments. Please report problems
|
|
|
with the x11vnc configure, make, etc. on your system (if your system
|
|
|
is known to compile other GNU packages successfully).
|
|
|
|
|
|
There are precompiled x11vnc binaries built by other groups that are
|
|
|
available at the following locations:
|
|
|
Debian: (.deb) [143]http://packages.debian.org/x11vnc
|
|
|
|
|
|
Slackware: (.tgz) [144]http://www.linuxpackages.net/ Redhat/Fedora:
|
|
|
(.rpm) [145]http://dag.wieers.com/packages/x11vnc/ Solaris: (pkg)
|
|
|
[146]http://www.sunfreeware.com/ wwexptools: (.tgz)
|
|
|
[147]http://www.bell-labs.com/project/wwexptools/packages.html The
|
|
|
last one, wwexptools, provides a variety of Unix binaries (Linux,
|
|
|
Solaris, HP-UX, IRIX, ...) with the intent of being compatible on a
|
|
|
wide range of OS releases. Find x11vnc near the bottom of that page
|
|
|
and select 'download info'.
|
|
|
|
|
|
Note: it appears some of the wwexptools x11vnc binaries are not
|
|
|
compiled with libz and libjpeg and so the fast compression encodings:
|
|
|
"Tight", "ZRLE", etc are not supported by those binaries. You can see
|
|
|
this by looking at the x11vnc output and if it says the encoding for a
|
|
|
client is "hextile" then likely the fast compression encodings are
|
|
|
missing. If you want optimal performance on your OS, you should see
|
|
|
the [148]build notes above for where to download libz and libjpeg, and
|
|
|
then build everything with gcc. For Solaris, the
|
|
|
http://www.sunfreeware.com/ packages are built with libz and libjpeg.
|
|
|
|
|
|
If the above binaries don't work and building x11vnc on your OS fails
|
|
|
(and all else fails!) you can try one of my motley collection of
|
|
|
[149]test binaries. Some may be old, some may have extra debugging
|
|
|
output, etc. One of them may work on your OS...
|
|
|
|
|
|
As a general note, the x11vnc program is simple enough you don't
|
|
|
really need to install a package: the binary will in most cases work
|
|
|
as is and from any location (as long as your system libraries are not
|
|
|
too old, etc). So, for Linux distributions that are not one of the
|
|
|
above, the x11vnc binary from the above packages has a good chance of
|
|
|
working. You can "install" it by just copying the x11vnc binary to the
|
|
|
desired directory in your PATH. Tip on extracting files from a Debian
|
|
|
package: extract the archive via a command like: "ar x
|
|
|
x11vnc_0.6-2_i386.deb" and then you can find the binary in the
|
|
|
resulting data.tar.gz tar file. Also, rpm2cpio(1) is useful in
|
|
|
extracting files from rpm packages.
|
|
|
|
|
|
Q-5: Where can I get a VNC Viewer binary (or source code) for the
|
|
|
Operating System I will be viewing from?
|
|
|
|
|
|
To obtain VNC viewers for the viewing side (Windows, Mac OS, or Unix)
|
|
|
try here:
|
|
|
* [150]http://www.tightvnc.com/download.html
|
|
|
* [151]http://www.realvnc.com/download-free.html
|
|
|
* [152]http://sourceforge.net/projects/cotvnc/
|
|
|
|
|
|
Q-6: How can I see all of x11vnc's command line options and
|
|
|
documentation on how to use them?
|
|
|
|
|
|
Run: x11vnc -opts to list just the option names or run: x11vnc
|
|
|
-help for long descriptions about each option. The output is listed
|
|
|
[153]here as well.
|
|
|
|
|
|
Q-7: I don't like typing arcane command line options every time I
|
|
|
start x11vnc. What can I do? Is there a config file? Or a GUI?
|
|
|
|
|
|
You could create a shell script that calls x11vnc with your options:
|
|
|
#!/bin/sh
|
|
|
#
|
|
|
# filename: X11vnc (i.e. not "x11vnc")
|
|
|
# It resides in a directory in $PATH. "chmod 755 X11vnc" has been run on it.
|
|
|
#
|
|
|
x11vnc -nap -wait 50 -localhost -rfbauth $HOME/.vnc/passwd -display :0 $*
|
|
|
|
|
|
a similar thing can be done via aliases in your shell (bash, tcsh,
|
|
|
csh, etc..).
|
|
|
|
|
|
Or as of Jun/2004 in the libvncserver CVS you can use the simple
|
|
|
$HOME/.x11vncrc config file support. If that file exists, each line is
|
|
|
taken as a command line option. E.g. the above would be:
|
|
|
# this is a comment in my ~/.x11vncrc file
|
|
|
nap
|
|
|
wait 50 # this is a comment to the end of the line.
|
|
|
-localhost # note: the leading "-" is optional.
|
|
|
rfbauth /home/fred/.vnc/passwd
|
|
|
display :0
|
|
|
|
|
|
At some point this config file support will be expanded.
|
|
|
|
|
|
As of Dec/2004 in the libvncserver CVS there is now a simple tcl/tk
|
|
|
GUI based on the remote-control functionality that was added. It's not
|
|
|
particularly user-friendly, it just provides a point and click mode to
|
|
|
set all the many x11vnc parameters and obtain help on them. See the
|
|
|
[154]-gui option for more info. Examples: "x11vnc ... -gui" and
|
|
|
"x11vnc ... -gui other:0" in the latter case the gui is displayed on
|
|
|
other:0, not the X display x11vnc is polling.
|
|
|
|
|
|
Q-8: Can I make x11vnc more quiet and also go into the background
|
|
|
after starting up?
|
|
|
|
|
|
Use the [155]-q and [156]-bg options, respectively. (also: -quiet is
|
|
|
an alias for -q)
|
|
|
|
|
|
Note that under -bg the stderr messages will be lost unless you use
|
|
|
the "[157]-o logfile" option.
|
|
|
|
|
|
Q-9: Sometimes when a VNC viewer dies abruptly, x11vnc also dies with
|
|
|
the error message like: "Broken pipe". I'm using the -forever mode and
|
|
|
I want x11vnc to keep running.
|
|
|
|
|
|
As of Jan/2004 in the libvncserver CVS the SIGPIPE signal is ignored.
|
|
|
So if a viewer client terminates abruptly, libvncserver will notice on
|
|
|
the next I/O operation and will close the connection and continue on.
|
|
|
|
|
|
Up until of Apr/2004 the above fix only works for BSD signal systems
|
|
|
(Linux, FreeBSD, ...) For SYSV systems there is a workaround in my
|
|
|
[158]x11vnc.c file. It also has an [159]option -sigpipe exit to have
|
|
|
x11vnc clean up and exit upon receiving SIGPIPE.
|
|
|
|
|
|
[Win2VNC Related]
|
|
|
|
|
|
Q-10: I have two separate machine displays in front of me, one Windows
|
|
|
the other X11: can I use x11vnc in combination with Win2VNC in
|
|
|
dual-screen mode to pass the keystrokes and mouse motions to the X11
|
|
|
display?
|
|
|
|
|
|
Yes, for best response start up x11vnc with the "[160]-nofb" option
|
|
|
(disables framebuffer polling, and does other optimizations) on the
|
|
|
secondary display (X11) machine. Then start up Win2VNC on the primary
|
|
|
display (Windows) referring it to the secondary display.
|
|
|
|
|
|
This will also work X11 to X11 using [161]x2vnc, however you would
|
|
|
probably just want to avoid VNC and use x2x for that.
|
|
|
|
|
|
For reference, here are some links to Win2VNC-like programs for
|
|
|
multiple monitor setups:
|
|
|
* [162]Original Win2VNC
|
|
|
* [163]Enhanced Win2VNC and [164]sourceforge link
|
|
|
* [165]x2vnc
|
|
|
* [166]x2x also [167]here
|
|
|
* [168]zvnc (MorphOS)
|
|
|
|
|
|
All of them will work with x11vnc (except x2x where it is not needed).
|
|
|
|
|
|
Q-11: I am running Win2VNC on my Windows machine and I'm trying to
|
|
|
create a dual-screen mode with my second display monitor by running
|
|
|
"x11vnc -nofb". Whenever I initiate the connection Win2VNC quickly
|
|
|
disconnects and x11vnc says something like:
|
|
|
rfbProcessClientNormalMessage: read: Connection reset by peer
|
|
|
|
|
|
Is the default visual of the X display you run x11vnc on low color
|
|
|
(e.g. 8 bit per pixel PseudoColor)? (you can run xdpyinfo to check,
|
|
|
look in the "screen" section). There seems to be a bug in Win2VNC in
|
|
|
that it cannot deal correctly with colormaps (PseudoColor is the most
|
|
|
common example of a visual with a colormap).
|
|
|
|
|
|
If so, there are a couple options. 1) Can you set the default visual
|
|
|
on your display to be depth 24 TrueColor? Sun machines often have 8+24
|
|
|
overlay/multi-depth visuals, and you can make the default visual depth
|
|
|
24 TrueColor (see fbconfig(1) and Xsun(1)). 2) As of Feb/2004, in the
|
|
|
libvncserver CVS, x11vnc has the [169]-visual option to allow you to
|
|
|
force the framebuffer visual to whatever you want (this usually messes
|
|
|
up the colors unless you are very clever). In this case, the option
|
|
|
provides a convenient workaround for the Win2VNC bug:
|
|
|
x11vnc -nofb -visual TrueColor -display :0 ...
|
|
|
|
|
|
So the visual will be set to 8bpp TrueColor and Win2VNC can handle
|
|
|
this. Since Win2VNC does not use the framebuffer data there should be
|
|
|
no problems in doing this.
|
|
|
[Color Issues]
|
|
|
|
|
|
Q-12: The X display I run x11vnc on is only 8 bits per pixel (bpp)
|
|
|
PseudoColor (i.e. only 256 distinct colors). The x11vnc colors may
|
|
|
start out OK, but after a while the colors are incorrect in certain
|
|
|
windows.
|
|
|
|
|
|
Use the [170]-flashcmap option to have x11vnc watch for changes in the
|
|
|
colormap, and propagate those changes back to connected clients. This
|
|
|
can be slow (since the whole screen must be updated over the network
|
|
|
whenever the colormap changes). This flashing colormap behavior often
|
|
|
happens if an application installs its own private colormap when the
|
|
|
mouse is in its window. "netscape -install" is a well-known historical
|
|
|
example of this. Consider reconfiguring the system to 16 bpp or depth
|
|
|
24 TrueColor if at all possible.
|
|
|
|
|
|
Also note that in some rare cases the [171]-notruecolor option has
|
|
|
corrected colors on 8bpp displays. The red, green, and blue masks were
|
|
|
non-zero in 8bpp PseudoColor on an obscure setup, and this option
|
|
|
corrected the problems.
|
|
|
|
|
|
Q-13: Color problems: Why are the colors for some windows messed up in
|
|
|
x11vnc? BTW, I have an X display that has nice overlay/multi-depth
|
|
|
visuals of different color depths: e.g. there are both depth 8 and 24
|
|
|
visuals available at the same time.
|
|
|
|
|
|
You may want to review the [172]previous question regarding 8 bpp
|
|
|
PseudoColor.
|
|
|
|
|
|
On some hardware (Sun/SPARC, Sgi), the [173]-overlay option discussed
|
|
|
a couple paragraphs down may solve this for you (you may want to skip
|
|
|
to it directly).
|
|
|
|
|
|
Run xdpyinfo(1) to see what the default visual is and what the depths
|
|
|
of the other visuals are. Does the default visual have a depth of 8?
|
|
|
If it does, can you possibly re-configure your X server to make the
|
|
|
depth 24 visual the default? If you can do it, this will save you a
|
|
|
lot of grief WRT colors and x11vnc (and for general usage too!). Here
|
|
|
is how I do this on an old Sparcstation 20 running Solaris 9 with SX
|
|
|
graphics
|
|
|
xinit -- -dev /dev/fb defclass TrueColor defdepth 24
|
|
|
|
|
|
and it works nicely (note: to log into console from the dtlogin
|
|
|
window, select "Options -> Command Line Login", then login and enter
|
|
|
the above command). See the -dev section of the Xsun(1) manpage for a
|
|
|
description of the above arguments. If you have root permission, a
|
|
|
more permanent and convenient thing to do is to record the arguments
|
|
|
in a line like:
|
|
|
:0 Local local_uid@console root /usr/openwin/bin/Xsun -dev /dev/fb defclass
|
|
|
TrueColor defdepth 24
|
|
|
|
|
|
in /etc/dt/config/Xservers (copy /usr/dt/config/Xservers). Also look
|
|
|
at the fbconfig(1) and related manpages (e.g. ffbconfig, m64config,
|
|
|
pgxconfig, SUNWjfb_config, etc ...) for hardware framebuffer settings
|
|
|
that may achieve the same effect.
|
|
|
|
|
|
In general for non-Sun machines, look at the "-cc class" and related
|
|
|
options in your X server manpage (perhaps Xserver(1)), it may allow
|
|
|
modifying the default visual (e.g. "-cc 4", see <X11/X.h> for the
|
|
|
visual class numbers). On XFree86 some video card drivers (e.g. Matrox
|
|
|
mga) have settings like Option "Overlay" "24,8" to support multi-depth
|
|
|
overlays. For these, use the "-cc 4" X server command line option to
|
|
|
get a depth 24 default visual.
|
|
|
|
|
|
|
|
|
The -overlay mode: Another option is if the system with overlay
|
|
|
visuals is a Sun system running Solaris or Sgi running IRIX you can
|
|
|
use the [174]-overlay x11vnc option (Aug/2004) to have x11vnc use the
|
|
|
Solaris XReadScreen(3X11) function to poll the "true view" of the
|
|
|
whole screen at depth 24 TrueColor. XReadDisplay(3X11) is used on
|
|
|
IRIX. This is useful for Legacy applications (older versions of
|
|
|
Cadence CAD apps are mentioned by x11vnc users) that require the
|
|
|
default depth be 8bpp, or the app will use a 8bpp visual even if depth
|
|
|
24 visuals are available, and so the default depth workaround
|
|
|
described in the previous paragraph is not sufficient for these apps.
|
|
|
|
|
|
Misc. notes on -overlay mode: An amusing by-product of -overlay mode
|
|
|
is that mouse cursor shape is correct. The -overlay mode may be
|
|
|
somewhat slower than normal mode due to the extra framebuffer
|
|
|
manipulations that must be performed. Also, on Solaris there is a bug
|
|
|
in that for some popup menus, the windows they overlap will have
|
|
|
painting errors (flashing colors) while the popup is up (a workaround
|
|
|
is to disable SaveUnders by passing -su to Xsun, e.g. in your
|
|
|
/etc/dt/config/Xservers file).
|
|
|
|
|
|
|
|
|
Colors still not working correctly? Run xwininfo on the application
|
|
|
with the messed up colors to verify that the depth of its visual is
|
|
|
different from the default visual depth (gotten from xdpyinfo). One
|
|
|
possible workaround in this case is to use the [175]-id option to
|
|
|
point x11vnc at the application window itself. If the application is
|
|
|
complicated (lots of toplevel windows and popup menus) this may not be
|
|
|
acceptable, and may even crash x11vnc (but not the application).
|
|
|
|
|
|
It is theoretically possible to solve this problem in general (see
|
|
|
xwd(1) for example), but it does not seem trivial or sufficiently fast
|
|
|
for x11vnc to be able to do so in real time. Fortunately the
|
|
|
[176]-overlay option works for Solaris machines with overlay visuals
|
|
|
where most of this problem occurs.
|
|
|
|
|
|
Q-14: How do I figure out the window id to supply to the -id windowid
|
|
|
option?
|
|
|
|
|
|
Run the xwininfo program in a terminal. It will ask you to click on
|
|
|
the desired application window. After clicking, it will print out much
|
|
|
information, including the window id (e.g. 0x6000010). Also, the
|
|
|
visual and depth of the window printed out is often useful in
|
|
|
debugging x11vnc [177]problems.
|
|
|
|
|
|
When using -id windowid, note that some VNC viewers will have problems
|
|
|
rendering screens that have a width that is not a multiple of 4. Try
|
|
|
to manually adjust the window width before starting x11vnc -id ....
|
|
|
|
|
|
Also, as of Dec/2004 libvncserver CVS you can use "[178]-id pick" to
|
|
|
have x11vnc run xwininfo(1) for you and after you click the window it
|
|
|
extracts the windowid. Besides "pick" there is also "id:root" to allow
|
|
|
you to go back to root window when doing remote-control.
|
|
|
|
|
|
Q-15: Why don't menus or other transient windows come up when I am
|
|
|
using the -id windowid option to view a single application window?
|
|
|
|
|
|
This is related to the behavior of the XGetImage(3X11) and
|
|
|
XShmGetImage() interfaces regarding backingstore, saveunders, etc. The
|
|
|
way the image is retrieved depends on some aspects of how the X server
|
|
|
maintains the display image data and whether other windows are
|
|
|
clipping or obscuring it. See the XGetImage man page for more details.
|
|
|
If you disable BackingStore and SaveUnders in the X server you should
|
|
|
be able to see these transient windows.
|
|
|
|
|
|
If things are not working and you still want to do the single window
|
|
|
polling, try the [179]-sid windowid option ("shifted" windowid).
|
|
|
|
|
|
x11vnc is known to crash under both -id and -sid, so both modes are
|
|
|
still experimental. Please report any reproducible bugs.
|
|
|
|
|
|
Q-16: My X display is depth 24 at 24bpp (instead of the normal depth
|
|
|
24 at 32bpp). I'm having lots of color and visual problems with x11vnc
|
|
|
and/or vncviewer. What's up?
|
|
|
|
|
|
First off, depth 24 at 24bpp (bpp=bits-per-pixel) is fairly uncommon
|
|
|
and can cause problems in general. It also can be slower than depth 24
|
|
|
at 32bpp. You might want to switch to 32bpp (for XFree86 see the
|
|
|
"-fbbpp 32", DefaultFbBpp, FbBpp and related options). Perhaps you
|
|
|
have 24bpp because the video memory of the machine is low and the
|
|
|
screen wouldn't fit in video RAM at 32bpp. For this case depth 16 at
|
|
|
16bpp might be an acceptable option.
|
|
|
|
|
|
In any event x11vnc should handle depth 24 at 24bpp (although
|
|
|
performance may be slower). There are some caveats involving the
|
|
|
viewer however:
|
|
|
|
|
|
The RealVNC Unix viewer cannot handle 24bpp from the server, it will
|
|
|
say: "main: setPF: not 8, 16 or 32 bpp?" and exit. I have not checked
|
|
|
the RealVNC Windows viewer.
|
|
|
|
|
|
So you need to use the TightVNC Unix viewer. However there are some
|
|
|
problems with that too. It seems libvncserver does not do 24bpp
|
|
|
correctly with the Tight encoding. The colors and screen ultimately
|
|
|
get messed up. So you have to use a different encoding with the
|
|
|
TightVNC vncviewer, try "zlib", "hextile", or one of the other
|
|
|
encodings (e.g. vncviewer -encodings "zlib hextile" ...). I have not
|
|
|
checked the TightVNC or UltraVNC Windows viewers.
|
|
|
|
|
|
It appears the older RealVNC Unix viewers (e.g. 3.3.3 and 3.3.7) can
|
|
|
handle 24bpp from the server, so you may want to use those. They
|
|
|
evidently request 32 bpp and libvncserver obliges.
|
|
|
|
|
|
Now coming the opposite direction if you are running the vncviewer on
|
|
|
the 24bpp display, TightVNC will fail with "Can't cope with 24
|
|
|
bits-per-pixel. Sorry." and RealVNC will fail with "main: Error:
|
|
|
couldn't find suitable pixmap format" so evidently you cannot use
|
|
|
24bpp for the vncviewers to work on that X display.
|
|
|
[Xterminals]
|
|
|
|
|
|
Q-17: Can I use x11vnc to view and interact with an Xterminal (e.g.
|
|
|
NCD) that is not running UNIX and so x11vnc cannot be run on it
|
|
|
directly?
|
|
|
|
|
|
You can, but it will likely be very wasteful of network bandwidth
|
|
|
since you will be polling the X display over the network as opposed to
|
|
|
over the local hardware. To do this, run x11vnc on a UNIX machine as
|
|
|
close as possible network-wise (e.g. same switch) to the Xterminal
|
|
|
machine. Use the [180]-display option to point the display to that of
|
|
|
the Xterminal (you'll of course need basic X11 permission to do that)
|
|
|
and also supply the [181]-noshm option (this enables the polling over
|
|
|
the network).
|
|
|
|
|
|
The response will likely be sluggish. This mode is not recommended
|
|
|
except for "quick checks" of hard to get to X servers. Use something
|
|
|
like -wait 150 to cut down on the polling rate. You may also need
|
|
|
[182]-flipbyteorder if the colors get messed up due to endian byte
|
|
|
order differences.
|
|
|
|
|
|
Q-18: How do I get my X permissions (MIT-MAGIC-COOKIE) correct for a
|
|
|
Unix/Linux machine acting as an Xterminal?
|
|
|
|
|
|
If the display machine is a traditional Xterminal (where the X server
|
|
|
runs on the Xterminal box, but all of the X client applications run on
|
|
|
a central server), the login display manager, and hence the
|
|
|
MIT-MAGIC-COOKIE auth files, are on the central server and not on the
|
|
|
Xterminal where the X server and x11vnc processes are running. Somehow
|
|
|
the MIT-MAGIC-COOKIE auth file data must be copied to the Xterminal.
|
|
|
If $HOME/.Xauthority is exported via NFS (this is insecure of course),
|
|
|
then x11vnc can simply pick it up via NFS (you may need to use the
|
|
|
[183]-auth option to point to the correct file). Other options include
|
|
|
copying the auth file using scp, or something like:
|
|
|
central-server> xauth nextract - xterm123:0 | ssh xterm123 xauth nmerge -
|
|
|
|
|
|
and then perhaps ssh from central-server to xterm123 to start x11vnc.
|
|
|
You can use "xauth -f /path/to/cookie-file list" to examine the
|
|
|
contents of the cookie in a file "/path/to/cookie-file". See the
|
|
|
xauth(1) manpage for more details.
|
|
|
|
|
|
If the display name needs to be changed between the two hosts, see
|
|
|
[184]this note on the "xauth add ..." command.
|
|
|
|
|
|
A less secure option is to run something like "xhost +127.0.0.1" while
|
|
|
sitting at the Xterminal to allow cookie-free local access for x11vnc.
|
|
|
You can run "xhost -127.0.0.1" after x11vnc connects if you want.
|
|
|
|
|
|
If the Xterminal is really stripped down and doesn't have any user
|
|
|
accounts, NFS, etc. you'll need to contact your system administrator
|
|
|
to set something up. It can be done!
|
|
|
|
|
|
Not recommended, but as a last resort, you could have x11vnc [185]poll
|
|
|
the Xterminal over the network.
|
|
|
|
|
|
Note: use of Display Manager (gdm, kdm, ...) auth cookie files (i.e.
|
|
|
from /var/..., /tmp/..., or elsewhere) may require modification via
|
|
|
xauth(1) to correctly include the display x11vnc refers to (e.g.
|
|
|
"xauth -f cookie-file add :0 . 45be51ae2ce9dfbacd882ab3ef8e96b1",
|
|
|
where 45be51... was found from an "xauth -f /var/... list") or other
|
|
|
reasons. See xauth(1) manpage for full details on how to transfer an
|
|
|
MIT-MAGIC-COOKIE between machines and displays.
|
|
|
|
|
|
[Remote Control]
|
|
|
|
|
|
Q-19: How do I stop x11vnc once it is running in the background?
|
|
|
|
|
|
As of Dec/2004 in the libvncserver CVS there is a remote control
|
|
|
feature. It can change a huge amount of things on the fly: see the
|
|
|
[186]-remote and [187]-query options. To shut down the running x11vnc
|
|
|
server just type "x11vnc -R stop". To disconnect all clients do
|
|
|
"x11vnc -R disconnect:all", etc.
|
|
|
|
|
|
For older versions: If the [188]-forever option has not been supplied,
|
|
|
x11vnc will automatically exit after the first client disconnects. In
|
|
|
general you will have to kill the x11vnc process This can be done via:
|
|
|
"kill NNNNN" (where NNNNN is the x11vnc process id number found from
|
|
|
ps(1)), or "pkill x11vnc", or "killall x11vnc" (Linux only).
|
|
|
|
|
|
If you have not put x11vnc in the background via the [189]-bg option
|
|
|
or shell & operator, then simply press Ctrl-C in the shell where
|
|
|
x11vnc is running to stop it. Potential Gotcha: If somehow your
|
|
|
Keypress of Ctrl-C went through x11vnc to the Xserver that then
|
|
|
delivered it to x11vnc it is possible one or both of the Ctrl or C
|
|
|
keys will be left stuck in the pressed down state in the Xserver.
|
|
|
Tapping the stuck key (either via a new x11vnc or at the physical
|
|
|
console) will release it from the stuck state. If the keyboard seems
|
|
|
to be acting strangely it is often fixed by tapping Ctrl, Shift, and
|
|
|
Alt. Alternatively, the [190]-clear_mods option and [191]-clear_keys
|
|
|
option can be used to release pressed keys at startup and exit.
|
|
|
|
|
|
Q-20: Can I change settings in x11vnc without having to restart it?
|
|
|
I.e., is there a way to remote control it?
|
|
|
|
|
|
Look at the [192]-remote (same as -R) and [193]-query (same as -Q)
|
|
|
options added in the Dec/2004 libvncserver CVS. They allow nearly
|
|
|
everything to be changed dynamically and settings to be queried.
|
|
|
Examples: "x11vnc -R shared", "x11vnc -R forever", "x11vnc -R
|
|
|
scale:3/4", "x11vnc -Q modtweak", "x11vnc -R stop", "x11vnc -R
|
|
|
disconnect:all", etc.. These commands do not start a x11vnc server,
|
|
|
but rather communicate with one that is already running. The X display
|
|
|
(VNC_CONNECT property) is used as the communication channel, so the X
|
|
|
permissions and DISPLAY must be set up correctly for communication to
|
|
|
be possible.
|
|
|
|
|
|
There is also a simple tcl/tk gui based on this remote control
|
|
|
mechanism. See the [194]-gui option for more info.
|
|
|
|
|
|
[Security and Permissions]
|
|
|
|
|
|
Q-21: How do I create a VNC password for use with x11vnc?
|
|
|
|
|
|
You may already have one in $HOME/.vnc/passwd if you have used, say,
|
|
|
the vncserver program from the regular RealVNC or TightVNC packages
|
|
|
(i.e. launching the Xvnc server). Otherwise, you could use the
|
|
|
vncpasswd(1) program from those packages. The libvncserver package
|
|
|
also comes with a simple program: storepasswd in the examples
|
|
|
directory. And as of Jun/2004 in the libvncserver CVS x11vnc supports
|
|
|
the -storepasswd "pass" "file" [195]option, which is the the same
|
|
|
functionality of storepasswd. Be sure to quote the "pass" if it
|
|
|
contains shell meta characters, spaces, etc. Example:
|
|
|
x11vnc -storepasswd 'sword*fish' $HOME/myvncpasswd
|
|
|
|
|
|
You then use the password via the x11vnc option: [196]-rfbauth
|
|
|
$HOME/myvncpasswd
|
|
|
|
|
|
Compared to vncpasswd(1) the latter two methods are a somewhat unsafe
|
|
|
because the password is specified on the command line and so someone
|
|
|
may see it by using ps(1) or looking over your shoulder. Also watch
|
|
|
out for the command winding up in your shell's history file (history
|
|
|
-c is often a way to clear it).
|
|
|
|
|
|
x11vnc also has the [197]-passwdfile and -passwd/-viewpasswd plain
|
|
|
text (i.e. not obscured like the -rfbauth VNC passwords) password
|
|
|
options.
|
|
|
|
|
|
Q-22: Can I have two passwords for VNC viewers, one for full access
|
|
|
and the other for view-only access to the display?
|
|
|
|
|
|
Yes, as of May/2004 in the libvncserver CVS there is the
|
|
|
[198]-viewpasswd option to supply the view-only password. Note the
|
|
|
full-access password option [199]-passwd must be supplied at the same
|
|
|
time. E.g.: -passwd sword -viewpasswd fish.
|
|
|
|
|
|
To avoid specifying the passwords on the command line (where they
|
|
|
could be observed via the ps(1) command by any user) you can use the
|
|
|
[200]-passwdfile option to specify a file containing plain text
|
|
|
passwords. Presumably this file is readable only by you, and ideally
|
|
|
it is located on the machine x11vnc is run on (to avoid being snooped
|
|
|
on over the network). The first line of this file is the full-access
|
|
|
password. If there is a second line in the file and it is non-blank,
|
|
|
it is taken as the view-only password. (use "__EMPTY__" to supply an
|
|
|
empty one).
|
|
|
|
|
|
View-only passwords currently do not work for the [201]-rfbauth
|
|
|
password option (standard VNC password storing mechanism). FWIW, note
|
|
|
that although the output (usually placed in $HOME/.vnc/passwd) by the
|
|
|
vncpasswd or storepasswd programs (or from x11vnc -storepasswd) looks
|
|
|
encrypted they are really just obscured to avoid "casual" password
|
|
|
stealing. It takes almost no skill to figure out how to extract the
|
|
|
plain text passwords from $HOME/.vnc/passwd since it is very
|
|
|
straight-forward to work out what to do from the VNC source code.
|
|
|
|
|
|
Q-23: Can I fine tune what types of user input are allowed? E.g. have
|
|
|
some users just be able to move the mouse, but not click or type
|
|
|
anything?
|
|
|
|
|
|
As of Feb/2005, the [202]-input option allows you to do this. "K",
|
|
|
"M", and "B" stand for Keystroke, Mouse-motion, and Button-clicks,
|
|
|
respectively. The setting: "-input M" makes attached viewers only able
|
|
|
to move the mouse. "-input KMB,M" lets normal clients do everything
|
|
|
and enables view-only clients to move the mouse.
|
|
|
|
|
|
These settings can also be applied on a per-viewer basis via the
|
|
|
remote control mechanism or the GUI. E.g. x11vnc -R input:hostname:M
|
|
|
|
|
|
Q-24: Why does x11vnc exit as soon as the VNC viewer disconnects? And
|
|
|
why doesn't it allow more than one VNC viewer to connect at the same
|
|
|
time?
|
|
|
|
|
|
These defaults are simple safety measures to avoid someone unknowingly
|
|
|
leaving his X11 desktop exposed (to the internet, say) for long
|
|
|
periods of time. Use the [203]-forever option (aka -many) to have
|
|
|
x11vnc wait for more connections after the first client disconnects.
|
|
|
Use the [204]-shared option to have x11vnc allow multiple clients to
|
|
|
connect simultaneously.
|
|
|
|
|
|
Recommended additional safety measures include using ssh ([205]see
|
|
|
above), stunnel, or a VPN to authenticate and encrypt the viewer
|
|
|
connections or to at least use the -rfbauth passwd-file [206]option to
|
|
|
use VNC password protection (or [207]-passwdfile) It is up to you to
|
|
|
apply these security measures, they will not be done for you
|
|
|
automatically.
|
|
|
|
|
|
Q-25: Can I limit which machines incoming VNC clients can connect
|
|
|
from?
|
|
|
|
|
|
Yes, look at the [208]-allow and [209]-localhost options to limit
|
|
|
connections by hostname or IP address. E.g.
|
|
|
x11vnc -allow 192.168.0.1,192.168.0.2
|
|
|
|
|
|
for those two hosts or
|
|
|
x11vnc -allow 192.168.0.
|
|
|
|
|
|
for a subnet. For individual hosts you can use the hostname instead of
|
|
|
the IP number, e.g.: "-allow snoopy", and "-allow darkstar,wombat".
|
|
|
Note that -localhost is the same as "-allow 127.0.0.1"
|
|
|
|
|
|
For more control, build libvncserver with libwrap support
|
|
|
[210](tcp_wrappers) and then use /etc/hosts.allow See hosts_access(5)
|
|
|
for complete details.
|
|
|
|
|
|
Q-26: How do I build x11vnc/libvncserver with libwrap (tcp_wrappers)
|
|
|
support?
|
|
|
|
|
|
Here is one way to pass this information to the configure script:
|
|
|
env CPPFLAGS=-DUSE_LIBWRAP LDFLAGS=-lwrap ./configure
|
|
|
|
|
|
then run make as usual. This requires libwrap and its development
|
|
|
package (tcpd.h) to be installed on the build machine. If additional
|
|
|
CPPFLAGS or LDFLAGS options are needed supply them as well using
|
|
|
quotes.
|
|
|
|
|
|
The resulting x11vnc then uses libwrap/tcp_wrappers for connections.
|
|
|
The service name you will use in /etc/hosts.allow and /etc/hosts.deny
|
|
|
is "vnc", e.g.:
|
|
|
vnc: 192.168.100.3 .example.com
|
|
|
|
|
|
Note that if you run x11vnc out of [211]inetd you do not need to build
|
|
|
x11vnc with libwrap support because the /usr/sbin/tcpd reference in
|
|
|
/etc/inetd.conf handles the tcp_wrappers stuff.
|
|
|
|
|
|
Q-27: Can I have x11vnc only listen on one network interface (e.g.
|
|
|
internal LAN) rather than having it listen on all network interfaces
|
|
|
and relying on -allow to filter unwanted connections out?
|
|
|
|
|
|
As of Mar/2005 in the libvncserver CVS, there is the "[212]-listen
|
|
|
ipaddr" option that enables this. For ipaddr either supply the desired
|
|
|
network interface's IP address (or use a hostname that resolves to it)
|
|
|
or use the string "localhost". For additional filtering simultaneously
|
|
|
use the "[213]-allow host1,..." option to allow only specific hosts
|
|
|
in.
|
|
|
|
|
|
This option is useful if you want insure that no one can even begin a
|
|
|
dialog with x11vnc from untrusted network interfaces (e.g. ppp0). The
|
|
|
option [214]-localhost now implies "-listen localhost" since that is
|
|
|
what most people expect it to do.
|
|
|
|
|
|
Q-28: Now that -localhost implies listening only on the loopback
|
|
|
interface, how I can occasionally allow in a non-local host via the
|
|
|
allowonce remote control command?
|
|
|
|
|
|
To do this specify "[215]-allow localhost". Unlike [216]-localhost
|
|
|
this will leave x11vnc listening on all interfaces (but of course only
|
|
|
allowing in local connections, e.g. ssh redirs). Then you can later
|
|
|
run "x11vnc -R allowonce:somehost" or use to gui to permit a one-shot
|
|
|
connection from a remote host.
|
|
|
|
|
|
Note that if you do a lot of changing of the listening interface
|
|
|
([217]-listen option) via remote control or gui, you may need to also
|
|
|
manually adjust the [218]-allow list if you unexpectedly get into a
|
|
|
state where the allow list cannot match any hosts that would be coming
|
|
|
in on the listening interface. If you just toggle [219]-localhost on
|
|
|
and off x11vnc should see to it that you never get into such a state.
|
|
|
|
|
|
Q-29: How can I tunnel my connection to x11vnc via an encrypted SSH
|
|
|
channel between two Unix machines?
|
|
|
|
|
|
See the description earlier on this page on [220]how to tunnel VNC via
|
|
|
SSH from Unix to Unix. A number of ways are described along with some
|
|
|
issues you may encounter.
|
|
|
|
|
|
Other secure encrypted methods exists, e.g. stunnel, IPSEC, various
|
|
|
VPNs, etc.
|
|
|
|
|
|
Q-30: How can I tunnel my connection to x11vnc via an encrypted SSH
|
|
|
channel from Windows using an SSH client like Putty?
|
|
|
|
|
|
[221]Above we described how to tunnel VNC via SSH from Unix to Unix,
|
|
|
you may want to review it. To do this from Windows using Putty it
|
|
|
would go something like this:
|
|
|
* In the Putty dialog window under 'Session' enter the hostname or
|
|
|
IP number of the Unix machine with display to be viewed.
|
|
|
* Make sure the SSH protocol is selected and the server port is
|
|
|
correct.
|
|
|
* Under 'Connections/SSH/Tunnels' Add a Local connection with
|
|
|
'Source port: 5900' and 'Destination: localhost:5900'
|
|
|
* Log into the remote machine by pressing 'Open' and supplying
|
|
|
username, password, etc.
|
|
|
* In that SSH shell, start up x11vnc by typing the command: x11vnc
|
|
|
-display :0 plus any other desired options.
|
|
|
* Finally, start up your VNC Viewer in Windows and enter
|
|
|
'localhost:0' as the VNC server.
|
|
|
|
|
|
You can keep all of the settings in a Putty 'Saved Session'. Also,
|
|
|
once everything is working, you can consider putting x11vnc -display
|
|
|
:0 (plus other cmdline options) in the 'Remote command' Putty setting
|
|
|
under 'Connections/SSH'. It is likely possible to script the whole
|
|
|
process in a BAT file including launching the VNC viewer by using the
|
|
|
plink Putty utility. Send us the script if you get that working.
|
|
|
|
|
|
For extra protection feel free to run x11vnc with the [222]-localhost
|
|
|
and [223]-rfbauth/[224]-passwdfile options.
|
|
|
|
|
|
If the machine you SSH into via Putty is not the same machine with the
|
|
|
X display you wish to view (e.g. your company provides incoming SSH
|
|
|
access to a gateway machine), then you need to change the above Putty
|
|
|
dialog setting to: 'Destination: otherhost:5900', Once logged in,
|
|
|
you'll need to do a second login (ssh or rsh) to the workstation
|
|
|
machine 'otherhost' and then start up x11vnc on it.
|
|
|
|
|
|
As discussed [225]above another option is to first start the VNC
|
|
|
viewer in "listen" mode, and then launch x11vnc with the
|
|
|
"[226]-connect localhost" option to establish the reverse connection.
|
|
|
In this case a Remote port redirection (not Local) is needed for port
|
|
|
5500 instead of 5900 (i.e. 'Source port: 5500' and
|
|
|
'Destination: localhost:5500' for a Remote connection).
|
|
|
|
|
|
Q-31: Can I prompt the user at the local X display whether the
|
|
|
incoming VNC client should be accepted or not? Can I decide to make
|
|
|
some clients view-only? How about running an arbitrary program to make
|
|
|
the decisions?
|
|
|
|
|
|
Yes, look at the "[227]-accept command" option, it allows you to
|
|
|
specify an external command that is run for each new client. (use
|
|
|
quotes around the command if it contains spaces, etc.). If the
|
|
|
external command returns 0 the client is accepted, otherwise the
|
|
|
client is rejected. See below how to also accept clients view-only.
|
|
|
|
|
|
The external command will have the RFB_CLIENT_IP environment variable
|
|
|
set to the client's numerical IP address, RFB_CLIENT_PORT its port
|
|
|
number. Similarly for RFB_SERVER_IP and RFB_SERVER_PORT to allow
|
|
|
identification of the tcp virtual circuit. DISPLAY will be set to that
|
|
|
of the X11 display being polled. Also, RFB_X11VNC_PID is set to the
|
|
|
x11vnc process id (e.g. in case you decided to kill it), RFB_CLIENT_ID
|
|
|
will be an id number, and RFB_CLIENT_COUNT the number of other clients
|
|
|
currently connected. RFB_MODE will be "accept".
|
|
|
|
|
|
As a special case, "-accept popup" will instruct x11vnc to create its
|
|
|
own simple popup window. To accept the client press "y" or click mouse
|
|
|
on the "Yes" button. To reject the client press "n" or click mouse on
|
|
|
the "No" button. To accept the client View-only, press "v" or click
|
|
|
mouse on the "View" button. If the [228]-viewonly option has been
|
|
|
supplied, the "View" action will not be present: the whole display is
|
|
|
view only in that case.
|
|
|
|
|
|
The popup window times out after 120 seconds, to change this behavior
|
|
|
use "-accept popup:N" where N is the number of seconds (use 0 for no
|
|
|
timeout). More tricks: "-accept popupmouse" will only take mouse click
|
|
|
responses, while "-accept popupkey" will only take keystroke responses
|
|
|
(popup takes both). After any of the 3 popup keywords you can supply a
|
|
|
position of the window: +N+M, (the default is to center the window)
|
|
|
e.g. -accept popupmouse+10+10.
|
|
|
|
|
|
Also as a special case "-accept xmessage" will run the xmessage(1)
|
|
|
program to prompt the user whether the client should be accepted or
|
|
|
not. This requires that you have xmessage installed and available via
|
|
|
PATH. In case it is not already on your system, the xmessage program
|
|
|
is available at [229]ftp://ftp.x.org/
|
|
|
|
|
|
To include view-only decisions for the external commands, prefix the
|
|
|
command something like this: "yes:0,no:*,view:3 mycommand ..." This
|
|
|
associates the three actions: yes(accept), no(reject), and
|
|
|
view(accept-view-only), with the numerical return codes. Use "*"
|
|
|
instead of a number to set the default action (e.g. in case the
|
|
|
external command returns an unexpected return code).
|
|
|
|
|
|
Here is an example -accept script called accept_or_lock. It uses
|
|
|
xmessage and xlock (replace with your screen lock command, maybe it is
|
|
|
"xscreensaver-command -lock", or kdesktop_lock, or "dtaction
|
|
|
LockDisplay"). It will prompt the user at the X display whether to
|
|
|
accept, reject, or accept view-only the client, but if the prompt
|
|
|
times out after 60 seconds the screen is locked and the VNC client is
|
|
|
accepted. This allows the remote access when no one is at the display.
|
|
|
#!/bin/sh
|
|
|
#
|
|
|
# accept_or_lock: prompt user at X display whether to accept an incoming
|
|
|
# VNC connection. If timeout expires, screen is locked
|
|
|
# and the VNC viewer is accepted (allows remote access
|
|
|
# when no one is sitting at the display).
|
|
|
#
|
|
|
# usage: x11vnc ... -forever -accept 'yes:0,no:*,view:4 accept_or_lock'
|
|
|
#
|
|
|
xmessage -buttons yes:2,no:3,view-only:4 -center \
|
|
|
-timeout 60 "x11vnc: accept connection from $RFB_CLIENT_IP?"
|
|
|
rc=$?
|
|
|
if [ $rc = 0 ]; then
|
|
|
xlock &
|
|
|
sleep 5
|
|
|
exit 0
|
|
|
elif [ $rc = 2 ]; then
|
|
|
exit 0
|
|
|
elif [ $rc = 4 ]; then
|
|
|
exit 4
|
|
|
fi
|
|
|
exit 1
|
|
|
|
|
|
Stefan Radman has written a nice dtksh script [230]dtVncPopup for use
|
|
|
in CDE environments to do the same sort of thing. Information on how
|
|
|
to use it is found at the top of the file. He encourages you to
|
|
|
provide feedback to him to help improve the script.
|
|
|
|
|
|
Note that in all cases x11vnc will block while the external command or
|
|
|
popup is being run, so attached clients will not receive screen
|
|
|
updates, etc during this period.
|
|
|
|
|
|
To run a command when a client disconnects, use the "[231]-gone
|
|
|
command" option. This is for the user's convenience only: the return
|
|
|
code of the command is not interpreted by x11vnc. The same environment
|
|
|
variables are set as in "-accept command" (except that RFB_MODE will
|
|
|
be "gone").
|
|
|
|
|
|
Q-32: Does x11vnc support Unix usernames and passwords? Can I further
|
|
|
limit the set of Unix usernames who can connect to the VNC desktop?
|
|
|
|
|
|
Until the VNC protocol and libvncserver support this things will be
|
|
|
approximate at best. Hopefully, it will not be too long to wait for
|
|
|
such support.
|
|
|
|
|
|
One approximate method involves starting x11vnc with the
|
|
|
[232]-localhost option. This basically requires the viewer user to log
|
|
|
into the workstation where x11vnc is running via their Unix username
|
|
|
and password, and then somehow set up a port redirection of his
|
|
|
vncviewer connection to make it appear to emanate from the local
|
|
|
machine. As discussed above, ssh is useful for this: ssh -l username
|
|
|
-L 5900:localhost:5900 hostname ... See the ssh wrapper scripts
|
|
|
mentioned [233]elsewhere on this page. Of course a malicious user
|
|
|
could allow other users to get in through his channel, but that is a
|
|
|
problem with every method. Another thing to watch out for is a
|
|
|
malicious user on the viewer side (where ssh is running) trying to
|
|
|
sneak in through the ssh port redirection.
|
|
|
|
|
|
Regarding limiting the set of Unix usernames who can connect, the
|
|
|
traditional way would be to further require a VNC password to supplied
|
|
|
(-rfbauth, -passwd, etc). A scheme that avoids a second password
|
|
|
involves using the [234]-accept option that runs a program to examine
|
|
|
the connection information to determine which user is connecting from
|
|
|
the local machine. For example, the program could use the ident
|
|
|
service on the local machine (normally ident should not be trusted
|
|
|
over the network, but on the local machine it should be accurate:
|
|
|
otherwise root has been compromised and so there are more serious
|
|
|
problems!). An example script passed in via -accept scriptname that
|
|
|
deduces the Unix username and limits who can be accepted might look
|
|
|
something like this:
|
|
|
#!/bin/sh
|
|
|
if [ "$RFB_CLIENT_IP" != "127.0.0.1" -o "$RFB_SERVER_IP" != "127.0.0.1" ]; then
|
|
|
exit 1 # something fishy... reject it.
|
|
|
fi
|
|
|
user=`echo "$RFB_CLIENT_PORT, $RFB_SERVER_PORT" | nc -w 1 $RFB_CLIENT_IP 113 \
|
|
|
| grep 'USERID.*UNIX' | head -1 | sed -e 's/[\r ]//g' | awk -F: '{print
|
|
|
$4}'`
|
|
|
|
|
|
for okuser in fred barney wilma betty
|
|
|
do
|
|
|
if [ "X$user" = "X$okuser" ]; then
|
|
|
exit 0 # accept it
|
|
|
fi
|
|
|
done
|
|
|
exit 1 # reject it
|
|
|
|
|
|
For this to work with ssh port redirection, the ssh option
|
|
|
UsePrivilegeSeparation must be enabled.
|
|
|
|
|
|
Q-33: I start x11vnc as root because it is launched via inetd(1) or a
|
|
|
display manager like gdm(1). Can I have x11vnc later switch to a
|
|
|
different user?
|
|
|
|
|
|
As of Feb/2005 x11vnc has the [235]-users option that allows things
|
|
|
like this. Please read the documentation on it (in the x11vnc -help
|
|
|
output) carefully for features and caveats. It's use can often
|
|
|
decrease security unless care is taken. A nice use of it is "-users
|
|
|
+nobody" that switches to the Unix user nobody right after connections
|
|
|
to the X display are established.
|
|
|
|
|
|
Q-34: I use a screen-lock when I leave my workstation (e.g.
|
|
|
xscreensaver or xlock). When I remotely access my workstation desktop
|
|
|
via x11vnc I can unlock the desktop fine, but I am worried people will
|
|
|
see my activities on the physical monitor. What can I do to prevent
|
|
|
this, or at least make it more difficult?
|
|
|
|
|
|
Probably most work environments would respect your privacy if you
|
|
|
powered off the monitor. Also remember if people have physical access
|
|
|
to your workstation they basically can do anything they want with it
|
|
|
(e.g. install a backdoor for later use, etc).
|
|
|
|
|
|
In any event, as of Jun/2004 there is an experimental utility to make
|
|
|
it more difficult for nosey people to see your x11vnc activities. The
|
|
|
source for it is [236]blockdpy.c The idea behind it is simple (but
|
|
|
obviously not bulletproof): when a VNC client attaches to x11vnc put
|
|
|
the display monitor in the DPMS "off" state, if the DPMS state ever
|
|
|
changes immediately start up the screen-lock program. The x11vnc user
|
|
|
will notice something is happening and think about what to do next
|
|
|
(while the screen is in a locked state).
|
|
|
|
|
|
This works (or at least has a chance of working) because if the
|
|
|
intruder moves the mouse or presses a key on the keyboard, the monitor
|
|
|
wakes up out of the DPMS off state, and this induces the screen lock
|
|
|
program to activate as soon as possible. Of course there are cracks in
|
|
|
this, the eavesdropper could detach your monitor and insert a non-DPMS
|
|
|
one, and there are race conditions. As mentioned above this is not
|
|
|
bulletproof. A really robust solution would likely require X server
|
|
|
and perhaps even video hardware support.
|
|
|
|
|
|
The blockdpy utility is launched by the [237]-accept option and told
|
|
|
to exit via the [238]-gone option (the vnc client user should
|
|
|
obviously re-lock the screen before disconnecting!). Instructions can
|
|
|
be found in the source code for the utility at the above link.
|
|
|
|
|
|
Q-35: Can I have x11vnc automatically lock the screen when I
|
|
|
disconnect the VNC viewer?
|
|
|
|
|
|
Yes, a user mentions he uses the [239]-gone option under CDE to run a
|
|
|
screen lock program:
|
|
|
x11vnc -display :0 -forever -gone 'dtaction LockDisplay'
|
|
|
|
|
|
Other possibilities are:
|
|
|
x11vnc -display :0 -forever -gone 'xscreensaver-command -lock'
|
|
|
x11vnc -display :0 -forever -gone 'kdesktop_lock'
|
|
|
x11vnc -display :0 -forever -gone 'xlock &'
|
|
|
|
|
|
|
|
|
[Display Managers and Services]
|
|
|
|
|
|
Q-36: How can I run x11vnc as a "service" that is always available?
|
|
|
|
|
|
There are a number of ways to do this. The primary thing you need to
|
|
|
decide is whether you want x11vnc to connect to the X session on the
|
|
|
machine 1) regardless of who (or if anyone) has the X session, or 2)
|
|
|
only if a certain user has the X session. Because X sessions are
|
|
|
protected by X permissions (XAUTHORITY and $HOME/.Xauthority) the
|
|
|
automatically started x11vnc will of course need to have sufficient
|
|
|
permissions to connect to the X display.
|
|
|
|
|
|
Here are some ideas:
|
|
|
* Use the description under "Continuously" in the [240]FAQ on x11vnc
|
|
|
and Display Managers
|
|
|
* Use the description in the [241]FAQ on x11vnc and inetd(1)
|
|
|
* Start x11vnc from your $HOME/.xsession (or $HOME/.xinitrc)
|
|
|
* Although less reliable, see the [242]x11vnc_loop rc.local hack
|
|
|
below.
|
|
|
|
|
|
The display manager scheme will not be specific to which user has the
|
|
|
X session unless a test is specifically put into the display startup
|
|
|
script (often named Xsetup). The inetd(1) scheme may or may not be
|
|
|
specific to which user has the X session (and it may not be able to do
|
|
|
all users via the XAUTHORITY permission issues).
|
|
|
|
|
|
The $HOME/.xsession scheme is obviously is specific to a particular
|
|
|
user. If you do not know what a $HOME/.xsession script is or how to
|
|
|
use one, perhaps your desktop has a "session startup commands"
|
|
|
configuration option. The command to be run in the .xsession or
|
|
|
.xinitrc file may look like this:
|
|
|
x11vnc -logfile $HOME/.x11vnc.log -rfbauth $HOME/.vnc/passwd -forever -bg
|
|
|
|
|
|
plus any other options you desire.
|
|
|
|
|
|
Q-37: How can I use x11vnc to connect to an X login screen like xdm,
|
|
|
GNOME gdm, KDE kdm, or CDE dtlogin? (i.e. nobody is logged into an X
|
|
|
session yet).
|
|
|
|
|
|
One time only. If the X login screen is running and you just want to
|
|
|
connect to it once:
|
|
|
|
|
|
On Linux it seems it is possible to do this by just adjusting the
|
|
|
XAUTHORITY environment variable to point to the MIT-COOKIE auth file
|
|
|
while running x11vnc as root, e.g. for the gnome display manager, gdm:
|
|
|
x11vnc -auth /var/gdm/:0.Xauth -display :0
|
|
|
|
|
|
(the [243]-auth option sets XAUTHORITY). There will be a similar thing
|
|
|
for xdm using however a different auth directory path (perhaps
|
|
|
something like /var/lib/xdm/authdir/authfiles/A:0-XQvaJk for xdm or
|
|
|
/var/lib/kdm/A:0-crWk72 for kdm, where the random characters in
|
|
|
basename will vary a bit).
|
|
|
|
|
|
Tricks: another place to look for the auth file is via ps(1) output
|
|
|
for the X server process to find any -auth argument (e.g. ps wwwwaux |
|
|
|
grep auth). Also, sometimes this command is useful: ps wwwweaux | tr '
|
|
|
' '\n' | grep XAUTHORITY | sort -u
|
|
|
|
|
|
gdm seems to have an annoying setting that causes x11vnc (and any
|
|
|
other X clients) to be killed after the user logs in. Setting
|
|
|
KillInitClients=false in the [daemon] section of /etc/X11/gdm/gdm.conf
|
|
|
avoids this. Otherwise, just restart x11vnc and then reconnect your
|
|
|
viewer.
|
|
|
|
|
|
For dtlogin in addition to the above sort of trick (BTW, the auth file
|
|
|
should be in /var/dt), you'll also need to add something like
|
|
|
Dtlogin*grabServer:False to the Xconfig file (/etc/dt/config/Xconfig
|
|
|
or /usr/dt/config/Xconfig on Solaris, see [244]the example at the end
|
|
|
of this FAQ). Then restart dtlogin, e.g.: /etc/init.d/dtlogin stop;
|
|
|
/etc/init.d/dtlogin start or reboot.
|
|
|
|
|
|
Continuously. Have x11vnc reattach each time the X server is
|
|
|
restarted (i.e. after each logout):
|
|
|
|
|
|
To make x11vnc always attached to the the X server (please consider
|
|
|
the security implications of this!) including the login screen you
|
|
|
will need to add a command to a display manager startup script. The
|
|
|
name of the script file depends on desktop used and seem to be:
|
|
|
GNOME /etc/X11/gdm/Init/Default (or Init/:0)
|
|
|
KDE /etc/kde*/kdm/Xsetup
|
|
|
XDM /etc/X11/xdm/Xsetup (or xdm/Xsetup_0)
|
|
|
CDE /etc/dt/config/Xsetup
|
|
|
|
|
|
although the exact location can depend on operating system and
|
|
|
distribution. See the documentation for your display manager: gdm(1),
|
|
|
kdm(1), xdm(1), dtlogin(1) for additional details. The above
|
|
|
Dtlogin*grabServer:False step will be needed for dtlogin here as well.
|
|
|
There may also be display number specific scripts: e.g. Xsetup_0 vs.
|
|
|
Xsetup, you need to watch out for.
|
|
|
|
|
|
In any event, the line you will add to the display manager script will
|
|
|
look something like:
|
|
|
/usr/local/bin/x11vnc -rfbauth /path/to/the/vnc/passwd -forever -bg
|
|
|
|
|
|
where you should customize the exact command to your needs. Note that
|
|
|
we do not need to specify -display or -auth because happily they are
|
|
|
already set for us in the DISPLAY and XAUTHORITY environment
|
|
|
variables.
|
|
|
|
|
|
You may also want to force the VNC port with something like "-rfbport
|
|
|
5900"
|
|
|
|
|
|
You may want to redirect the x11vnc output to a separate log file for
|
|
|
debugging. In that case replace the -bg above with something like:
|
|
|
1>> /var/tmp/x11vnc.log 2>&1 &
|
|
|
|
|
|
(or use the "[245]-o logfile" option).
|
|
|
_________________________________________________________________
|
|
|
|
|
|
Fedora/gdm: Here is an example of what we did on a vanilla install of
|
|
|
Fedora-C3 (seems to use gdm by default). Add a line like this to
|
|
|
/etc/X11/gdm/Init/:0
|
|
|
/usr/local/bin/x11vnc -rfbauth /etc/x11vnc.passwd -forever -bg -o /var/tmp/x1
|
|
|
1vnc.log
|
|
|
|
|
|
And then add this line to /etc/X11/gdm/gdm.conf in the [daemon]
|
|
|
section:
|
|
|
KillInitClients=false
|
|
|
|
|
|
Then restart: /usr/sbin/gdm-restart (or reboot). The
|
|
|
KillInitClients=false setting is important: without it x11vnc will be
|
|
|
killed immediately after the user logs in. Here are [246]full details
|
|
|
on how to configure gdm
|
|
|
_________________________________________________________________
|
|
|
|
|
|
Solaris/dtlogin: Here is an example of what we did on a vanilla
|
|
|
install of Solaris:
|
|
|
Make the directory /etc/dt/config:
|
|
|
mkdir -p /etc/dt/config
|
|
|
|
|
|
Copy over the Xconfig file for customization:
|
|
|
cp /usr/dt/config/Xconfig /etc/dt/config/Xconfig
|
|
|
|
|
|
Edit /etc/dt/config/Xconfig and uncomment the line:
|
|
|
Dtlogin*grabServer: False
|
|
|
|
|
|
Next, copy over Xsetup for customization:
|
|
|
cp /usr/dt/config/Xsetup /etc/dt/config/Xsetup
|
|
|
|
|
|
Edit /etc/dt/config/Xsetup and at the bottom put a line like:
|
|
|
/usr/local/bin/x11vnc -forever -o /var/tmp/x11vnc.log -bg
|
|
|
|
|
|
(tweaked to your local setup and preferences, a password via -rfbauth,
|
|
|
etc. would be a very good idea).
|
|
|
|
|
|
Restart the X server and dtlogin:
|
|
|
/etc/init.d/dtlogin stop
|
|
|
/etc/init.d/dtlogin start
|
|
|
|
|
|
(or reboot or maybe just restart the X session).
|
|
|
_________________________________________________________________
|
|
|
|
|
|
|
|
|
If you do not want to deal with any display manager startup scripts,
|
|
|
here is a kludgey script that can be run manually or out of a boot
|
|
|
file like rc.local: [247]x11vnc_loop It will need some local
|
|
|
customization before running. Because the XAUTHORITY auth file must be
|
|
|
guessed by this script, use of the display manager script above is
|
|
|
preferred.
|
|
|
|
|
|
If the machine is a traditional Xterminal you may want to read
|
|
|
[248]this FAQ.
|
|
|
|
|
|
Q-38: Can I run x11vnc out of inetd(1)? How about xinetd(1)?
|
|
|
|
|
|
Yes, perhaps a line something like this in /etc/inetd.conf will do it
|
|
|
for you:
|
|
|
|
|
|
5900 stream tcp nowait root /usr/sbin/tcpd /usr/local/bin/x11vnc_sh
|
|
|
|
|
|
where the shell script /usr/local/bin/x11vnc_sh uses the [249]-inetd
|
|
|
option and looks something like (you'll need to customize to your
|
|
|
settings).
|
|
|
#!/bin/sh
|
|
|
/usr/local/bin/x11vnc -inetd -display :0 -auth /home/fred/.Xauthority \
|
|
|
-rfbauth /home/fred/.vnc/passwd 2>> /tmp/x11vnc_sh.log
|
|
|
|
|
|
Note that you must redirect the standard error output to a log file or
|
|
|
/dev/null for proper operation via inetd (otherwise the standard error
|
|
|
also goes to the VNC vncviewer, and that confuses it greatly). If you
|
|
|
do not use a wrapper script as above but rather call x11vnc directly
|
|
|
in /etc/inetd.conf and do not redirect stderr, then you must specify
|
|
|
the -q (aka [250]-quiet) option: /usr/local/bin/x11vnc -q -inetd ...
|
|
|
or use -o logfile to collect the output in a file. The wrapper script
|
|
|
with stderr redirection to a log file is the recommended method
|
|
|
because the errors and warnings printed out are very useful in
|
|
|
troubleshooting problems.
|
|
|
|
|
|
Note also the need to set XAUTHORITY via [251]-auth to point to the
|
|
|
MIT-COOKIE auth file to get permission to connect to the X display
|
|
|
(setting and exporting the XAUTHORITY variable accomplishes the same
|
|
|
thing). See the x11vnc_loop file in the previous question for more
|
|
|
ideas on what that auth file may be, etc.
|
|
|
|
|
|
On Solaris you cannot have the bare number 5900 in /etc/inetd.conf,
|
|
|
you'll need to replace it with a word like x11vnc an then put
|
|
|
something like "x11vnc 5900/tcp" in /etc/services.
|
|
|
|
|
|
Be sure to look at your /etc/hosts.allow and /etc/hosts.deny settings
|
|
|
to limit the machines that can connect to this service (your
|
|
|
desktop!). For the above example with /etc/hosts.allow:
|
|
|
x11vnc_sh : 123.45.67.89
|
|
|
|
|
|
A really safe way to do things is to limit the above inetd to
|
|
|
localhost only (via /etc/hosts.allow) and use ssh to tunnel the
|
|
|
incoming connection. Using inetd for this prevents there being a tiny
|
|
|
window of opportunity between x11vnc starting up and your vncviewer
|
|
|
connecting to it. Always use a VNC password to further protect against
|
|
|
unwanted access.
|
|
|
|
|
|
For xinetd(1), one user reports he created the file
|
|
|
/etc/xinetd.d/x11vncservice containing the following:
|
|
|
# default: off
|
|
|
# description:
|
|
|
service x11vncservice
|
|
|
{
|
|
|
flags = REUSE NAMEINARGS
|
|
|
port = 5900
|
|
|
type = UNLISTED
|
|
|
socket_type = stream
|
|
|
protocol = tcp
|
|
|
wait = no
|
|
|
user = root
|
|
|
server = /usr/sbin/tcpd
|
|
|
server_args = /usr/local/bin/x11vnc_sh
|
|
|
disable = no
|
|
|
}
|
|
|
|
|
|
With the contents of /usr/local/bin/x11vnc_sh similar to the example
|
|
|
given above.
|
|
|
|
|
|
Q-39: How do I make x11vnc work with the Java VNC viewer applet in a
|
|
|
web browser?
|
|
|
|
|
|
To have x11vnc serve up a Java VNC viewer applet to any web browsers
|
|
|
that connect to it, run x11vnc with this [252]option:
|
|
|
-httpdir /path/to/the/java/classes/dir
|
|
|
|
|
|
(this directory will contain the files index.vnc and, for example,
|
|
|
VncViewer.jar) Note that libvncserver contains the TightVNC Java
|
|
|
classes jar file for your convenience. (it is the file
|
|
|
classes/VncViewer.jar in the source tree).
|
|
|
|
|
|
You will see output something like this:
|
|
|
14/05/2004 11:13:56 Autoprobing selected port 5900
|
|
|
14/05/2004 11:13:56 Listening for HTTP connections on TCP port 5800
|
|
|
14/05/2004 11:13:56 URL http://walnut:5800
|
|
|
14/05/2004 11:13:56 screen setup finished.
|
|
|
14/05/2004 11:13:56 The VNC desktop is walnut:0
|
|
|
PORT=5900
|
|
|
|
|
|
then you can connect to that URL with any Java enabled browser. Feel
|
|
|
free to customize the default index.vnc file in the classes directory.
|
|
|
|
|
|
Note that if you wanted to, you could also start the Java viewer
|
|
|
entirely from the viewer-side by having the jar file there and using
|
|
|
either the java or appletviewer commands to run the program.
|
|
|
|
|
|
Q-40: Are reverse connections (i.e. the VNC server connecting to the
|
|
|
VNC viewer) using "vncviewer -listen" and vncconnect(1) supported?
|
|
|
|
|
|
As of Mar/2004 in the libvncserver CVS x11vnc supports reverse
|
|
|
connections. On Unix one starts the VNC viewer in listen mode:
|
|
|
vncviewer -listen (see your documentation for Windows, etc), and then
|
|
|
starts up x11vnc with the [253]-connect option. To connect immediately
|
|
|
at x11vnc startup time use the "-connect host:port" option (use commas
|
|
|
for a list of hosts to connect to). The ":port" is optional (default
|
|
|
is 5500). If a file is specified instead: -connect /path/to/some/file
|
|
|
then that file is checked periodically (about once a second) for new
|
|
|
hosts to connect to.
|
|
|
|
|
|
To use the vncconnect(1) program (from the core VNC package at
|
|
|
www.realvnc.com) specify the [254]-vncconnect option to x11vnc (Note:
|
|
|
as of Dec/2004 -vncconnect is now the default). vncconnect(1) must be
|
|
|
pointed to the same X11 DISPLAY as x11vnc (since it uses X properties
|
|
|
to communicate with x11vnc). If you do not have or do not want to get
|
|
|
the vncconnect(1) program, the following script (named "Vncconnect")
|
|
|
may work if your xprop(1) supports the -set option:
|
|
|
#!/bin/sh
|
|
|
# usage: Vncconnect <host>
|
|
|
# Vncconnect <host:port>
|
|
|
# note: not all xprop(1) support -set.
|
|
|
#
|
|
|
xprop -root -f VNC_CONNECT 8s -set VNC_CONNECT "$1"
|
|
|
|
|
|
|
|
|
[Resource Usage and Performance]
|
|
|
|
|
|
Q-41: I have lots of memory, but why does x11vnc fail with shmget:
|
|
|
No space left on device or Minor opcode of failed request: 1
|
|
|
(X_ShmAttach)?
|
|
|
|
|
|
It is not a matter of free memory, but rather free shared memory (shm)
|
|
|
slots, also known as shm segments. This often occurs on a public
|
|
|
Solaris machine using the default of only 100 slots. You (or the owner
|
|
|
or root) can clean them out with ipcrm(1). x11vnc tries hard to
|
|
|
release its slots, but it, and other programs, are not always able to
|
|
|
(e.g. if kill -9'd).
|
|
|
|
|
|
Sometimes x11vnc will notice the problem with shm segments and tries
|
|
|
to get by with fewer, only giving a warning like this:
|
|
|
19/03/2004 10:10:58 shmat(tile_row) failed.
|
|
|
shmat: Too many open files
|
|
|
19/03/2004 10:10:58 error creating tile-row shm for len=4
|
|
|
19/03/2004 10:10:58 reverting to single_copytile mode
|
|
|
|
|
|
Here is a shell script [255]shm_clear to list and prompt for removal
|
|
|
of your unattached shm segments (attached ones are skipped). I use it
|
|
|
while debugging x11vnc (I use "shm_clear -y" to assume "yes" for each
|
|
|
prompt). If x11vnc is regularly not cleaning up its shm segments,
|
|
|
please contact me so we can work to improve the situation.
|
|
|
|
|
|
Longer term, on Solaris you can put something like this in
|
|
|
/etc/system:
|
|
|
set shmsys:shminfo_shmmax = 0x2000000
|
|
|
set shmsys:shminfo_shmmni = 0x1000
|
|
|
|
|
|
to sweep the problem under the rug (4096 slots). On Linux, examine
|
|
|
/proc/sys/kernel/shmmni; you can modify the value by writing to that
|
|
|
file.
|
|
|
|
|
|
Things are even more tight on Solaris 8 and earlier, there is a
|
|
|
default maximum number of shm segments per process of 6. The error is
|
|
|
the X server (not x11vnc) being unable to attach to the segments, and
|
|
|
looks something like this:
|
|
|
30/04/2004 14:04:26 Got connection from client 192.168.1.23
|
|
|
30/04/2004 14:04:26 other clients:
|
|
|
X Error of failed request: BadAccess (attempt to access private resource den
|
|
|
ied)
|
|
|
Major opcode of failed request: 131 (MIT-SHM)
|
|
|
Minor opcode of failed request: 1 (X_ShmAttach)
|
|
|
Serial number of failed request: 14
|
|
|
Current serial number in output stream: 17
|
|
|
|
|
|
This tight limit on Solaris 8 can be increased via:
|
|
|
set shmsys:shminfo_shmseg = 100
|
|
|
|
|
|
in /etc/system. See the next paragraph for more workarounds.
|
|
|
|
|
|
To minimize the number of shm segments used by x11vnc try using the
|
|
|
[256]-onetile option (corresponds to only 3 shm segments used, and
|
|
|
adding -fs 1.0 knocks it down to 2). If you are having much trouble
|
|
|
with shm segments, consider disabling shm completely via the
|
|
|
[257]-noshm option. Performance will be somewhat degraded but when
|
|
|
done over local machine sockets it should be acceptable (see an
|
|
|
[258]earlier question discussing -noshm).
|
|
|
|
|
|
Q-42: How can I make x11vnc use less system resources?
|
|
|
|
|
|
The [259]-nap and "[260]-wait n" (where n is the sleep between polls
|
|
|
in milliseconds, the default is 30 or so) option are good places to
|
|
|
start. Reducing the X server bits per pixel depth (e.g. to 16bpp or
|
|
|
even 8bpp) will further decrease memory I/O and network I/O. Using the
|
|
|
[261]-onetile option will use less memory and use fewer shared memory
|
|
|
slots (add [262]-fs 1.0 for one less slot).
|
|
|
|
|
|
Q-43: How can I make x11vnc use MORE system resources?
|
|
|
|
|
|
You can try [263]-threads and dial down the wait time (e.g. -wait 1)
|
|
|
and possibly dial down [264]-defer as well. Note that if you try to
|
|
|
increase the "frame rate" too much you can bog down the server end
|
|
|
with the extra work it needs to do compressing the framebuffer data,
|
|
|
etc.
|
|
|
|
|
|
That said, it is possible to "stream" video via x11vnc if the video
|
|
|
window is small enough. E.g. a 256x192 xawtv TV capture window (using
|
|
|
the x11vnc [265]-id option) can be streamed over a LAN or wireless at
|
|
|
a reasonable frame rate.
|
|
|
|
|
|
Q-44: I use x11vnc over a slow link with high latency (e.g. dialup
|
|
|
modem), is there anything I can do to speed things up?
|
|
|
|
|
|
Some things you might want to experiment with (most of which will help
|
|
|
performance on faster links as well):
|
|
|
|
|
|
X server/session parameters:
|
|
|
* Configure the X server bits per pixel to 16bpp or even 8bpp.
|
|
|
(reduces amount of data needed to be sent)
|
|
|
* Use a smaller desktop size (e.g. 1024x768 instead of 1280x1024)
|
|
|
* Make sure the desktop background is a solid color (the background
|
|
|
is resent every time it is re-exposed). Consider using the
|
|
|
[266]-solid [color] option.
|
|
|
* Configure your window manager or desktop "theme" to not use fancy
|
|
|
images, shading, and gradients for the window decorations, etc.
|
|
|
Disable Opaque moves, resizes, and animations.
|
|
|
* Avoid small scrolls of large windows using the Arrow keys or
|
|
|
scrollbar. Try to use PageUp/PageDown instead.
|
|
|
* On XFree86 turn on the Shadow Framebuffer to speed up reading.
|
|
|
(Option "ShadowFB" "true", and possibly Option "NoAccel" "true" as
|
|
|
well, in the Device section of /etc/X11/XF86Config) This disables
|
|
|
2D acceleration on the physical display and so is probably not
|
|
|
worth it, but could be of use in some situations.
|
|
|
|
|
|
VNC viewer parameters:
|
|
|
* Use a [267]TightVNC enabled viewer!
|
|
|
* Make sure the tight encoding is being used (look at vncviewer and
|
|
|
x11vnc outputs)
|
|
|
* Request 8 bits per pixel using -bgr233 (up to 4X speedup over
|
|
|
depth 24 TrueColor (32bpp), but colors will be off)
|
|
|
* The -depth option is similar to -bgr233 in reducing the requested
|
|
|
number of bits per pixel.
|
|
|
* Try increasing the TightVNC -compresslevel (compresses more on
|
|
|
server side before sending, but uses more CPU)
|
|
|
* Try reducing the TightVNC -quality (increases JPEG compression,
|
|
|
but is lossy)
|
|
|
* Try other VNC encodings via -encodings (tight is probably fastest,
|
|
|
but you should check)
|
|
|
* On the machine where vncviewer is run, make sure Backing Store is
|
|
|
enabled (XFree86 disables it by default causing re-exposures of
|
|
|
vncviewer to be very slow)
|
|
|
|
|
|
x11vnc parameters:
|
|
|
* Try using [268]-nodragging (no screen updates when dragging mouse,
|
|
|
but sometimes you miss visual feedback)
|
|
|
* Try the [269]-progressive pixelheight mode with the block
|
|
|
pixelheight 100 or so (delays sending vertical blocks since they
|
|
|
may change while viewer is receiving earlier ones)
|
|
|
* Set [270]-fs 1.0 (disables fullscreen updates)
|
|
|
* Try increasing [271]-wait or [272]-defer (reduces the maximum
|
|
|
"frame rate", but won't help much for large screen changes)
|
|
|
* If you just want to watch one (simple) window use [273]-id (cuts
|
|
|
down extraneous polling and updates, but can be buggy or
|
|
|
insufficient)
|
|
|
* Set [274]-nosel (disables all clipboard selection exchange)
|
|
|
* Use [275]-nocursor and [276]-nocursorpos (repainting the remote
|
|
|
cursor position and shape takes resources and round trips)
|
|
|
|
|
|
Q-45: When I drag windows around with the mouse or scroll up and down
|
|
|
things really bog down (unless I do the drag in a single, quick
|
|
|
motion). Is there anything to do to improve things?
|
|
|
|
|
|
As of Jan/2004 there are some improvements in the libvncserver CVS
|
|
|
tree. The default should now be much better than before and dragging
|
|
|
small windows around should no longer be a huge pain. If for some
|
|
|
reason these changes make matters worse, you can go back to the old
|
|
|
way via the "[277]-pointer_mode 1" option.
|
|
|
|
|
|
Also added was the [278]-nodragging option that disables all screen
|
|
|
updates while dragging with the mouse (i.e. mouse motion with a button
|
|
|
held down). This gives the snappiest response, but might be undesired
|
|
|
in some circumstances when you want to see the visual feedback while
|
|
|
dragging (e.g. menu traversal or text selection).
|
|
|
|
|
|
As of Dec/2004 in the libvncserver CVS the [279]-pointer_mode n option
|
|
|
was introduced. n=1 is the original mose, n=2 and improvement, etc..
|
|
|
See the -pointer_mode n help for more info.
|
|
|
|
|
|
Also, in some circumstances the [280]-threads option can improve
|
|
|
response considerably. Be forewarned that if more than one vncviewer
|
|
|
is connected at the same time then libvncserver may not be thread safe
|
|
|
(try to get the viewers to use different VNC encodings, e.g. tight and
|
|
|
ZRLE).
|
|
|
|
|
|
Q-46: Does x11vnc support the X DAMAGE Xserver extension to find
|
|
|
modified regions of the screen quickly and efficiently?
|
|
|
|
|
|
Yes, as of Mar/2005 in the libvncserver CVS x11vnc will use the X
|
|
|
DAMAGE extension by default if it is available on the display. This
|
|
|
requires libXdamage to be available in the build environment as well
|
|
|
(recent Linux distros and Solaris 10 have it).
|
|
|
|
|
|
The DAMAGE extension enables the X server to report changed regions of
|
|
|
the screen back to x11vnc. So x11vnc doesn't have to guess where the
|
|
|
changes are (by polling the entire screen every 1 or 2 seconds). The
|
|
|
use of X DAMAGE dramatically reduces the load when the screen is not
|
|
|
changing very much (i.e. most of the time). It also noticeably
|
|
|
improves updates, especially for very small changed areas (e.g. clock
|
|
|
ticking, cursor flashing, typing, etc).
|
|
|
|
|
|
Note that the DAMAGE extension does not speed up the actual reading of
|
|
|
pixels from the video card framebuffer memory, by, say, mirroring them
|
|
|
in main memory. So reading the fb is still painfully slow (e.g.
|
|
|
5MB/sec), and so even using X DAMAGE when large changes occur on the
|
|
|
screen the bulk of the time is still spent retrieving them.
|
|
|
|
|
|
Unfortunately the current Xorg DAMAGE extension implementation can at
|
|
|
times be overly cautious and report very large rectangles as "damaged"
|
|
|
even though only a small portion of the pixels have actually been
|
|
|
modified. This behavior is often the fault of the window manager (e.g.
|
|
|
it redraws the entire, unseen, frame window underneath the application
|
|
|
window when it gains focus), or the application itself (e.g. does
|
|
|
large, unnecessary repaints).
|
|
|
|
|
|
To work around this deficiency, x11vnc currently only trusts small
|
|
|
DAMAGE rectangles to contain real damage. The larger rectangles are
|
|
|
only used as hints to direct the traditional scanline polling (i.e. if
|
|
|
a scanline doesn't intersect a recent DAMAGE rectangle, the scan is
|
|
|
skipped). You can use the "[281]-xd_area A" option to adjust the size
|
|
|
of the trusted DAMAGE rectangles. The default is 20000 pixels (e.g. a
|
|
|
140x140 square, etc). Use "-xd_area 0" to disable the cutoff and trust
|
|
|
all DAMAGE rectangles.
|
|
|
|
|
|
The option "[282]-xd_mem f" may also be of use in tuning the
|
|
|
algorithm. To disable using DAMAGE entirely use "[283]-noxdamage".
|
|
|
|
|
|
[Mouse Cursor Shapes]
|
|
|
|
|
|
Q-47: Why isn't the mouse cursor shape (the little icon shape where
|
|
|
the mouse pointer is) correct as I move from window to window?
|
|
|
|
|
|
On X servers supporting XFIXES or Solaris/IRIX Overlay extensions it
|
|
|
is possible for x11vnc to do this correctly. See the paragraphs below.
|
|
|
|
|
|
Historically, the X11 mouse cursor shape (i.e. little picture: an
|
|
|
arrow, X, I-beam, resizer, etc) is one of the few write-only objects
|
|
|
in X11. That is, an application can tell the X server what the cursor
|
|
|
shape should be when the pointer is in a given window, but a program
|
|
|
(like x11vnc) unfortunately cannot read this information. I believe
|
|
|
this is because the cursor shape is often downloaded to the graphics
|
|
|
hardware (video card), but I could be mistaken.
|
|
|
|
|
|
A simple kludge is provided by the "[284]-cursor X" option that
|
|
|
changes the cursor when the mouse is on the root background (or any
|
|
|
window has the same cursor as the root background). Note that desktops
|
|
|
like GNOME or KDE often cover up the root background, so this won't
|
|
|
work for those cases. Also see the "[285]-cursor some" option for
|
|
|
additional kludges.
|
|
|
|
|
|
Note that as of Aug/2004 in the libvncserver CVS, on Solaris using the
|
|
|
SUN_OVL overlay extension and IRIX, x11vnc can show the correct mouse
|
|
|
cursor when the [286]-overlay option is supplied. See [287]this FAQ
|
|
|
for more info.
|
|
|
|
|
|
Also as of Dec/2004 in the libvncserver CVS XFIXES X extension support
|
|
|
has been added to allow exact extraction of the mouse cursor shape.
|
|
|
XFIXES fixes the problem of the cursor-shape being write-only: x11vnc
|
|
|
can now query the X server for the current shape and send it back to
|
|
|
the connected viewers. XFIXES is available on recent Linux Xorg based
|
|
|
distros and [288]Solaris 10.
|
|
|
|
|
|
The only XFIXES issue is the handling of alpha channel transparency in
|
|
|
cursors. If a cursor has any translucency then in general it must be
|
|
|
approximated to opaque RGB values. There are some situations where the
|
|
|
cursor transparency can also handled exactly: when the VNC Viewer
|
|
|
requires the cursor shape be drawn into the VNC framebuffer or if you
|
|
|
apply a patch to your VNC Viewer to extract hidden alpha channel data
|
|
|
under 32bpp. [289]Details can be found here.
|
|
|
|
|
|
Q-48: When using XFIXES cursorshape mode, some of the cursors look
|
|
|
really bad with extra black borders around the cursor and other cruft.
|
|
|
How can I improve their appearance?
|
|
|
|
|
|
This happens for cursors with transparency ("alpha channel"); regular
|
|
|
X cursors (bitmaps) should be correct. Unfortunately x11vnc 0.7 was
|
|
|
released with a very poor algorithm for approximating the
|
|
|
transparency, which led to the ugly black borders.
|
|
|
|
|
|
The problem is as follows: XFIXES allows x11vnc to retrieve the
|
|
|
current X server cursor shape, including the alpha channel for
|
|
|
transparency. For traditional bitmap cursors the alpha value will be 0
|
|
|
for completely transparent pixels and 255 for completely opaque
|
|
|
pixels; whereas for modern, eye-candy cursors an alpha value between 0
|
|
|
and 255 means to blend in the background colors to that degree with
|
|
|
the cursor colors. The pixel color blending formula is something like
|
|
|
this: Red = Red_cursor * a + Red_background * (1 - a), (where here 0
|
|
|
=< a =< 1), with similar for Green and Blue. The VNC protocol does not
|
|
|
currently support an alpha channel in cursors: it only supports
|
|
|
regular X bitmap cursors and Rich Cursors that have RGB (Red, Green,
|
|
|
Blue) color data, but no "A" = alpha data. So in general x11vnc has to
|
|
|
approximate a cursor with transparency to create a Rich Cursor. This
|
|
|
is easier said than done: some cursor themes have cursors with
|
|
|
complicated drop shadows and other forms of translucency.
|
|
|
|
|
|
Anyway, for the x11vnc 0.7.1 release the algorithm for approximating
|
|
|
transparency is much improved and hopefully gives decent cursor shapes
|
|
|
for most cursor themes and you don't have to worry about it.
|
|
|
|
|
|
In case it still looks bad for your cursor theme, there are (of
|
|
|
course!) some tunable parameters. The "[290]-alphacut n" option lets
|
|
|
you set the threshold "n" (between 0 and 255): cursor pixels with
|
|
|
alpha values below n will be considered completely transparent while
|
|
|
values equal to or above n will be completely opaque. The default is
|
|
|
240. The "[291]-alphafrac f" option tries to correct individual
|
|
|
cursors that did not fare well with the default -alphacut value: if a
|
|
|
cursor has less than fraction f (between 0.0 and 1.0) of its pixels
|
|
|
selected by the default -alphacut, the threshold is lowered until f of
|
|
|
its pixels are selected. The default fraction is 0.33.
|
|
|
|
|
|
Finally, there is an option [292]-alpharemove that is useful for
|
|
|
themes where many cursors are light colored (e.g. "whiteglass").
|
|
|
XFIXES returns the cursor data with the RGB values pre-multiplied by
|
|
|
the alpha value. If the white cursors look too grey, specify
|
|
|
-alpharemove to brighten them by having x11vnc divide out the alpha
|
|
|
value.
|
|
|
|
|
|
Q-49: In XFIXES mode, are there any hacks to handle cursor
|
|
|
transparency ("alpha channel") exactly?
|
|
|
|
|
|
As of Jan/2005 in the CVS, libvncserver has been modified to allow an
|
|
|
alpha channel (i.e. RGBA data) for Rich Cursors. So x11vnc can now
|
|
|
send the alpha channel data to libvncserver. However, this data will
|
|
|
only be used for VNC clients that do not support the
|
|
|
CursorShapeUpdates VNC extension (or have disabled it). It can be
|
|
|
disabled for all clients with the [293]-nocursorshape x11vnc option.
|
|
|
In this case the cursor is drawn, correctly blended with the
|
|
|
background, into the VNC framebuffer before being sent out to the
|
|
|
client. So the alpha blending is done on the x11vnc side. Use the
|
|
|
[294]-noalphablend option to disable this behavior (always approximate
|
|
|
transparent cursors with opaque RGB values).
|
|
|
|
|
|
The CursorShapeUpdates VNC extension complicates matters because the
|
|
|
cursor shape is sent to the VNC viewers supporting it, and the viewers
|
|
|
draw the cursor locally. This improves response over slow links. Alpha
|
|
|
channel data for these locally drawn cursors is not supported by the
|
|
|
VNC protocol.
|
|
|
|
|
|
However, in the libvncserver CVS there is a patch to the TightVNC
|
|
|
viewer to make this work for CursorShapeUpdates under some
|
|
|
circumstances. This hack is outside of the VNC protocol. It requires
|
|
|
the screens on both sides to be depth 24 at 32bpp (it uses the extra 8
|
|
|
bits to secretly hide the cursor alpha channel data). Not only does it
|
|
|
require depth 24 at 32bpp, but it also currently requires the client
|
|
|
and server to be of the same endianness (otherwise the hidden alpha
|
|
|
data gets reset to zero by a libvncserver translation function; we can
|
|
|
fix this at some point if there is interest). The patch is for the
|
|
|
TightVNC 1.3dev5 Unix vncviewer and it enables the TightVNC viewer to
|
|
|
do the cursor alpha blending locally. The patch code should give an
|
|
|
example on how to change the Windows TightVNC viewer to achieve the
|
|
|
same thing (send me the patch if you get that working).
|
|
|
|
|
|
[Mouse Pointer]
|
|
|
|
|
|
Q-50: Why does the mouse arrow just stay in one corner in my
|
|
|
vncviewer, whereas my cursor (that does move) is just a dot?
|
|
|
|
|
|
This default takes advantage of a [295]tightvnc extension
|
|
|
(CursorShapeUpdates) that allows specifying a cursor image shape for
|
|
|
the local VNC viewer. You may disable it with the [296]-nocursor
|
|
|
option to x11vnc if your viewer does not have this extension.
|
|
|
|
|
|
Note: as of Aug/2004 in the libvncserver CVS this should be fixed: the
|
|
|
default for non-tightvnc viewers (or ones that do not support
|
|
|
CursorShapeUpdates) will be to draw the moving cursor into the x11vnc
|
|
|
framebuffer. This can also be disabled via -nocursor.
|
|
|
|
|
|
Q-51: Can I take advantage of the TightVNC extension to the VNC
|
|
|
protocol where Cursor Positions Updates are sent back to all connected
|
|
|
clients (i.e. passive viewers can see the mouse cursor being moved
|
|
|
around by another viewer)?
|
|
|
|
|
|
Use the [297]-cursorpos option when starting x11vnc. A VNC viewer must
|
|
|
support the Cursor Positions Updates for the user to see the mouse
|
|
|
motions (the TightVNC viewers support this). As of Aug/2004 in the
|
|
|
libvncserver CVS -cursorpos is the default. See also [298]-nocursorpos
|
|
|
and [299]-nocursorshape.
|
|
|
|
|
|
Q-52: Is it possible to swap the mouse buttons (e.g. left-handed
|
|
|
operation), or arbitrarily remap them? How about mapping button clicks
|
|
|
to keystrokes, e.g. to partially emulate Mouse wheel scrolling?
|
|
|
|
|
|
You can remap the mouse buttons via something like: [300]-buttonmap
|
|
|
13-31 (or perhaps 12-21). Also, note that xmodmap(1) lets you directly
|
|
|
adjust the X server's button mappings, but in some circumstances it
|
|
|
might be more desirable to have x11vnc do it.
|
|
|
|
|
|
One user had an X server with only one mouse button(!) and was able to
|
|
|
map all of the VNC client mouse buttons to it via: -buttonmap 123-111.
|
|
|
|
|
|
Note that the [301]-debug_pointer option prints out much info for
|
|
|
every mouse/pointer event and is handy in solving problems.
|
|
|
|
|
|
To map mouse button clicks to keystrokes you can use the alternate
|
|
|
format where the keystrokes are enclosed between colons like this
|
|
|
:<KeySym>: in place of the mouse button digit. For a sequence of
|
|
|
keysyms separate them with "+" signs. Look in the include file
|
|
|
<X11/keysymdef.h>, or use xev(1), or -debug_keyboard to fine the
|
|
|
keysym names. Button clicks can also be included in the sequence via
|
|
|
the fake keysyms Button1, etc.
|
|
|
|
|
|
As an example, suppose the VNC viewer machine has a mouse wheel (these
|
|
|
generate button 4 and 5 events), but the machine that x11vnc is run on
|
|
|
only has the 3 regular buttons. In normal operation x11vnc will
|
|
|
discard the button 4 and 5 events. However, either of the following
|
|
|
button maps could possibly be of use emulating the mouse wheel events
|
|
|
in this case:
|
|
|
-buttonmap 12345-123:Prior::Next:
|
|
|
-buttonmap 12345-123:Up+Up+Up::Down+Down+Down:
|
|
|
|
|
|
Exactly what keystroke "scrolling" events they should be bound to
|
|
|
depends on one's taste. If this method is too approximate, one could
|
|
|
consider not using [302]-buttonmap but rather configuring the X server
|
|
|
to think it has a mouse with 5 buttons even though the physical mouse
|
|
|
does not.
|
|
|
|
|
|
Note that when a keysym-mapped mouse button is clicked down this
|
|
|
immediately generates the key-press and key-release events (for each
|
|
|
keysym in turn if the mapping has a sequence of keysyms). When the
|
|
|
mouse button goes back up nothing is generated.
|
|
|
|
|
|
If you include modifier keys like Shift_L instead of key-press
|
|
|
immediately followed by key-release the state of the modifier key is
|
|
|
toggled (however the initial state of the modifier key is ignored). So
|
|
|
to map the right button to type my name 'Karl Runge' I could use this:
|
|
|
-buttonmap 3-:Shift_L+k+Shift_L+a+r+l+space+Shift_L+r+Shift_L+u+n+g+e:
|
|
|
|
|
|
(yes, this is getting a little silly).
|
|
|
[Keyboard Issues]
|
|
|
|
|
|
Q-53: How can I get my AltGr and Shift modifiers to work between
|
|
|
keyboards for different languages?
|
|
|
|
|
|
The option [303]-modtweak should be of some use for this. It is a mode
|
|
|
that monitors the state of the Shift and AltGr Modifiers and tries to
|
|
|
deduce the correct keycode to send, possibly by sending fake modifier
|
|
|
key presses and releases in addition to the actual keystroke.
|
|
|
|
|
|
Update: As of Jul/2004 in the libvncserver CVS, -modtweak is now the
|
|
|
default (use -nomodtweak to get the old behavior). This was done
|
|
|
because it was noticed on newer XFree86 setups even on bland "us"
|
|
|
keyboards like "pc104 us" XFree86 included a "ghost" key with both "<"
|
|
|
and ">" it. This key does not exist on the keyboard (see [304]this FAQ
|
|
|
for more info). Without -modtweak there was then an ambiguity in the
|
|
|
reverse map keysym => keycode, making it so the "<" symbol could not
|
|
|
be typed.
|
|
|
|
|
|
Also see the [305]FAQ about the -xkb option for a more powerful method
|
|
|
of modifier tweaking for use on X servers with the XKEYBOARD
|
|
|
extension.
|
|
|
|
|
|
When trying to resolve keyboard mapping problems, note that the
|
|
|
[306]-debug_keyboard option prints out much info for every keystroke
|
|
|
and so can be useful debugging things.
|
|
|
|
|
|
Q-54: When I try to type a "<" (i.e. less than) instead I get ">"
|
|
|
(i.e. greater than)! Strangely, typing ">" works OK!!
|
|
|
|
|
|
Does your keyboard have a single key with both "<" and ">" on it? Even
|
|
|
if it doesn't, your X server may think your keyboard has such a key
|
|
|
(e.g. pc105 in the XF86Config file when it should be something else,
|
|
|
say pc104).
|
|
|
|
|
|
The problem here is that on the Xserver where x11vnc is run there are
|
|
|
two keycodes that correspond to the "<" keysym. Run something like
|
|
|
this to see:
|
|
|
|
|
|
xmodmap -pk | egrep -i 'KeyCode|less|greater'
|
|
|
There are 4 KeySyms per KeyCode; KeyCodes range from 8 to 255.
|
|
|
KeyCode Keysym (Keysym) ...
|
|
|
59 0x002c (comma) 0x003c (less)
|
|
|
60 0x002e (period) 0x003e (greater)
|
|
|
94 0x003c (less) 0x003e (greater)
|
|
|
|
|
|
That keycode 94 is the special key with both "<" and ">". When x11vnc
|
|
|
receives the "<" keysym over the wire from the remote VNC client, it
|
|
|
unfortunately maps it to keycode 94 instead of 59, and sends 94 to the
|
|
|
X server. Since Shift is down (i.e. you are Shifting the comma key),
|
|
|
the X server interprets this as Shifted-94, which is ">".
|
|
|
|
|
|
A workaround in the X server configuration is to "deaden" that special
|
|
|
key:
|
|
|
|
|
|
xmodmap -e "keycode 94 = "
|
|
|
|
|
|
However, one user said he had to do this:
|
|
|
|
|
|
xmodmap -e "keycode 94 = 0x002c 0x003c"
|
|
|
|
|
|
(If the numerical values are different for your setup, substitute the
|
|
|
ones that correspond to your display. The above xmodmap scheme can
|
|
|
often be used to work around other ambiguous keysym to keycode
|
|
|
mappings).
|
|
|
|
|
|
Alternatively, here are some x11vnc options to try to work around the
|
|
|
problem:
|
|
|
-modtweak
|
|
|
|
|
|
and
|
|
|
-remap less-comma
|
|
|
|
|
|
These are convenient in that they do not modify the actual X server
|
|
|
settings. The former ([307]-modtweak) is a mode that monitors the
|
|
|
state of the Shift and AltGr modifiers and tries to deduce the correct
|
|
|
keycode sequence to send. Since Jul/2004 -modtweak is now the default.
|
|
|
The latter ([308]-remap less-comma) is an immediate remapping of the
|
|
|
keysym less to the keysym comma when it comes in from a client (so
|
|
|
when Shift is down the comma press will yield "<").
|
|
|
|
|
|
See also the [309]FAQ about the -xkb option as a possible workaround
|
|
|
using the XKEYBOARD extension.
|
|
|
|
|
|
Note that the [310]-debug_keyboard option prints out much info for
|
|
|
every keystroke to aid debugging keyboard problems.
|
|
|
|
|
|
Q-55: I'm using an "international" keyboard (e.g. German "de", or
|
|
|
Danish "dk") and the -modtweak mode works well if the VNC viewer is
|
|
|
run on a Unix/Linux machine with a similar keyboard. But if I run the
|
|
|
VNC viewer on Unix/Linux with a different keyboard (e.g. "us") or
|
|
|
Windows with any keyboard, I can't type some keys like: "@", "$", "<",
|
|
|
">", etc. How can I fix this?
|
|
|
|
|
|
The problem with Windows is it does not seem to handle AltGr well. It
|
|
|
seems to fake it up by sending Control_L+Alt_R to applications. The
|
|
|
Windows VNC viewer sends those two down keystrokes out on the wire to
|
|
|
the VNC server, but when the user types the next key to get, e.g., "@"
|
|
|
the Windows VNC viewer sends events bringing the up the
|
|
|
Control_L+Alt_R keys, and then sends the "@" keysym by itself.
|
|
|
|
|
|
The Unix/Linux VNC viewer on a "us" keyboard does a similar thing
|
|
|
since "@" is the Shift of the "2" key. The keysyms Shift and "@" are
|
|
|
sent to the VNC server.
|
|
|
|
|
|
In both cases no AltGr is sent to the VNC server, but we know AltGr is
|
|
|
needed on the physical international keyboard to type a "@".
|
|
|
|
|
|
This all worked fine with x11vnc running with the [311]-modtweak
|
|
|
option (it figures out how to adjust the Modifier keys (Shift or
|
|
|
AltGr) to get the "@"). However it fails under recent versions of
|
|
|
XFree86 (and the X.org fork). These run the XKEYBOARD extension by
|
|
|
default and make heavy use of it to handle international keyboards.
|
|
|
|
|
|
To make a long story short, on these newer XFree86 setups the
|
|
|
traditional X keymap lookup x11vnc uses is no longer accurate. x11vnc
|
|
|
can't find the keysym "@" anywhere in the keymapping! (even though it
|
|
|
is in the XKEYBOARD extended keymapping).
|
|
|
|
|
|
How to Solve: As of Jul/2004 in the libvncserver CVS x11vnc has two
|
|
|
changes:
|
|
|
* -modtweak (tweak Modifier keys) is now the default (use
|
|
|
-nomodtweak to go back to the old way)
|
|
|
* there is a new option -xkb to use the XKEYBOARD extension API to
|
|
|
do the Modifier key tweaking.
|
|
|
|
|
|
The [312]-xkb option seems to fix all of the missing keys: "@", "<",
|
|
|
">", etc.: it is recommended that you try it if you have this sort of
|
|
|
problem. Let us know if there are any remaining problems (see the next
|
|
|
paragraph for some known problems). If you specify the -debug_keyboard
|
|
|
(aka -dk) option twice you will get a huge amount of keystroke
|
|
|
debugging output (send it along with any problems you report).
|
|
|
|
|
|
Known problems:
|
|
|
* One user had to disable a "ghost" Mode_switch key that was causing
|
|
|
problems under -xkb. His physical AltGr key was bound to
|
|
|
ISO_Level3_Shift (which seems to be the XKEYBOARD way of doing
|
|
|
things), while there was a ghost key Mode_switch (which seems to
|
|
|
be obsolete) in the mapping as well. Both of these keysyms were
|
|
|
bound to Mod5 and x11vnc was unfortunately choosing Mode_switch.
|
|
|
From the x11vnc -xkb -dk -dk output it was noted that Mode_switch
|
|
|
was attached to keycode 93 (no physical key generates this
|
|
|
keycode) while ISO_Level3_Shift was attached to keycode 113. The
|
|
|
keycode skipping option was used to disable the ghost key:
|
|
|
[313]-skip_keycodes 93
|
|
|
* In implementing -xkb we noticed that some characters were still
|
|
|
not getting through, e.g. "~" and "^". This is not really an
|
|
|
XKEYBOARD problem. What was happening was the VNC viewer was
|
|
|
sending the keysyms asciitilde and asciicircum to x11vnc, but on
|
|
|
the X server with the international keyboard those keysyms were
|
|
|
not mapped to any keys. So x11vnc had to skip them.
|
|
|
The way these characters are typically entered on international
|
|
|
keyboards is by "dead" (aka "mute") keys. E.g. to enter "~" at the
|
|
|
physical display the keysym dead_tilde is pressed and released
|
|
|
(this usually involves holding AltGr down while another key is
|
|
|
pressed) and then space is pressed. (this can also be used get
|
|
|
characters with the "~" symbol on top, e.g. "<22>" by typing "a"
|
|
|
instead of space).
|
|
|
What to do? In general the VNC protocol has not really solved this
|
|
|
problem: what should be done if the VNC viewer sends a keysym not
|
|
|
recognized by the VNC server side? Workarounds can possibly be
|
|
|
created using the [314]-remap x11vnc option:
|
|
|
-remap asciitilde-dead_tilde,asciicircum-dead_circumflex
|
|
|
etc. Use -remap filename if the list is long. Please send us your
|
|
|
workarounds for this problem on your keyboard. Perhaps we can have
|
|
|
x11vnc adjust automatically at some point. Also see the
|
|
|
[315]-add_keysyms option in the next paragraph.
|
|
|
* To complement the above workaround using the [316]-remap, an
|
|
|
option [317]-add_keysyms was added. This option instructs x11vnc
|
|
|
to bind any unknown Keysyms coming in from VNC viewers to unused
|
|
|
Keycodes in the X server. This modifies the global state of the X
|
|
|
server. When x11vnc exits it removes the extra keymappings it
|
|
|
created. Note that the -remap mappings are applied first, right
|
|
|
when the Keysym is received from a VNC viewer, and only after that
|
|
|
would -add_keysyms, or anything else, come into play.
|
|
|
|
|
|
Q-56: When typing I sometimes get double, triple, or more of my
|
|
|
keystrokes repeated. I'm sure I only typed them once, what can I do?
|
|
|
|
|
|
This may be due to an interplay between your X server's key autorepeat
|
|
|
delay and the extra time delays caused by x11vnc processing.
|
|
|
|
|
|
Short answer: disable key autorepeating by running the command "xset r
|
|
|
off" on the Xserver where x11vnc is run (restore via "xset r on") or
|
|
|
use the new (Jul/2004) [318]-norepeat x11vnc option. You will still
|
|
|
have autorepeating because that is taken care of on your VNC viewer
|
|
|
side. Update: as of Dec/2004 -norepeat is now the default. Use -repeat
|
|
|
to disable it.
|
|
|
|
|
|
Details: suppose you press a key DOWN and it generates changes in
|
|
|
large regions of the screen. The CPU and I/O work x11vnc does for the
|
|
|
large screen change could be longer than your X server's key
|
|
|
autorepeat delay. x11vnc may not get to processing the key UP event
|
|
|
until after the screen work is completed. The X server believes the
|
|
|
key has been held down all this time, and applies its autorepeat
|
|
|
rules.
|
|
|
|
|
|
Even without inducing changes in large regions of the screen, this
|
|
|
problem could arise when accessing x11vnc via a dialup modem or
|
|
|
otherwise high latency link (e.g. > 250 ms latency).
|
|
|
|
|
|
Look at the output of "xset q" for the "auto repeat delay" setting. Is
|
|
|
it low (e.g. < 300 ms)? If you turn off autorepeat completely: "xset r
|
|
|
off", does the problem go away?
|
|
|
|
|
|
The workaround is to manually apply "xset r off" and "xset r on" as
|
|
|
needed, or to use the [319]-norepeat (which has since Dec/2004 been
|
|
|
made the default). Note that with X server autorepeat turned off the
|
|
|
VNC viewer side of the connection will (nearly always) do its own
|
|
|
autorepeating so there is no big loss here, unless someone is also
|
|
|
working at the physical display and misses his autorepeating.
|
|
|
|
|
|
Q-57: The x11vnc -norepeat mode is in effect, but I still get repeated
|
|
|
keystrokes!!
|
|
|
|
|
|
Are you using x11vnc to log in to an X session? (as described in
|
|
|
[320]this FAQ) If so, x11vnc is starting before your session and it
|
|
|
disables autorepeat when you connect, and then your session startup
|
|
|
could be resetting the autorepeat to be on. Or it could be something
|
|
|
inside your desktop that decides to turn it back on. x11vnc in
|
|
|
-norepeat mode will not battle with things turning autorepeat back on.
|
|
|
(It will, however, turn it off whenever it goes from a state of zero
|
|
|
clients to one client).
|
|
|
|
|
|
Under these circumstances you will have to manually turn autorepeating
|
|
|
off by typing "xset r off" or "x11vnc -R norepeat" or a desktop
|
|
|
utility. If something in your desktop is automatically turning it back
|
|
|
on you will have to disable that somehow.
|
|
|
|
|
|
Q-58: The machine where I run x11vnc has an AltGr key, but the local
|
|
|
machine where I run the VNC viewer does not. Is there a way I can map
|
|
|
a local unused key to send an AltGr? How about a Compose key as well?
|
|
|
|
|
|
Something like "[321]-remap Super_R-Mode_switch" x11vnc option may
|
|
|
work. Note that Super_R is the "Right Windoze(tm) Flaggie" key; you
|
|
|
may want to choose another. The -debug_keyboard option comes in handy
|
|
|
in finding keysym names (so does xev(1)).
|
|
|
|
|
|
For Compose how about "-remap Menu-Multi_key" (note that Multi_key is
|
|
|
the official name for Compose). To do both at the same time: "-remap
|
|
|
Super_R-Mode_switch,Menu-Multi_key" or use "-remap filename" to
|
|
|
specify remappings from a file.
|
|
|
|
|
|
Q-59: I have a Sun machine I run x11vnc on. Its Sun keyboard has just
|
|
|
one Alt key labelled "Alt" and two Meta keys labelled with little
|
|
|
diamonds. The machine where I run the VNC viewer only has Alt keys.
|
|
|
How can I send a Meta keypress? (e.g. emacs needs this)
|
|
|
|
|
|
Here are a couple ideas. The first one is to simply use xmodmap(1) to
|
|
|
adjust the Sun X server. Perhaps xmodmap -e "keysym Alt_L = Meta_L
|
|
|
Alt_L" will do the trick. (there are other ways to do it, one user
|
|
|
used: xmodmap -e "keycode 26 = Meta_L" for his setup).
|
|
|
|
|
|
Since xmodmap(1) modifies the X server mappings you may not want to do
|
|
|
this (because it affects local work on that machine). Something like
|
|
|
the [322]-remap Alt_L-Meta_L to x11vnc may be sufficient for ones
|
|
|
needs, and does not modify the X server environment. Note that you
|
|
|
cannot send Alt_L in this case, maybe -remap Super_L-Meta_L would be a
|
|
|
better choice if the Super_L key is typically unused.
|
|
|
|
|
|
Q-60: Can I map a keystroke to a mouse button click on the remote
|
|
|
machine?
|
|
|
|
|
|
This can be done directly in some X servers using AccessX and
|
|
|
Pointer_EnableKeys, but is a bit awkward. It may be more convenient to
|
|
|
have x11vnc do the remapping. This can be done via the [323]-remap
|
|
|
option using the fake "keysyms" Button1, Button2, etc. as the "to"
|
|
|
keys (i.e. the ones after the "-")
|
|
|
|
|
|
As an example, consider a laptop where the VNC viewer is run that has
|
|
|
a touchpad with only two buttons. It is difficult to do a middle
|
|
|
button "paste" because (using XFree86 Emulate3Buttons) you have to
|
|
|
click both buttons on the touch pad at the same time. This remapping:
|
|
|
[324]-remap Super_R-Button2
|
|
|
|
|
|
maps the Super_R "flag" key press to the Button2 click, thereby making
|
|
|
X pasting a bit easier.
|
|
|
|
|
|
Note that once the key goes down, the button down and button up events
|
|
|
are generated immediately on the x11vnc side. When the key is released
|
|
|
(i.e. goes up) no events are generated.
|
|
|
|
|
|
[Screen Related Issues and Features]
|
|
|
|
|
|
Q-61: The remote display is larger (in number of pixels) than the
|
|
|
local display I am running the vncviewer on. I don't like the
|
|
|
vncviewer scrollbars, what I can do?
|
|
|
|
|
|
vncviewer has a option (usually accessible via F8 key or -fullscreen
|
|
|
option) for vncviewer to run in full screen, where it will
|
|
|
automatically scroll when the mouse is near the edge of the current
|
|
|
view. For quick scrolling, also make sure Backing Store is enabled on
|
|
|
the machine vncviewer is run on. (XFree86 disables it by default for
|
|
|
some reason, add Option "backingstore" to XF86Config on the vncviewer
|
|
|
side).
|
|
|
|
|
|
BTW, contact me if you are having problems with vncviewer in
|
|
|
fullscreen mode with your window manager (i.e. no keyboard response).
|
|
|
I have a workaround for vncviewer using XGrabServer().
|
|
|
|
|
|
There may also be scaling viewers out there (e.g. TightVNC on Windows)
|
|
|
that automatically shrink or expand the remote framebuffer to fit the
|
|
|
local display. Especially for hand-held devices. See also [325]this
|
|
|
FAQ on x11vnc scaling.
|
|
|
|
|
|
Q-62: Does x11vnc support server-side framebuffer scaling? (E.g. to
|
|
|
make the desktop smaller).
|
|
|
|
|
|
As of Jun/2004 in the libvncserver CVS x11vnc provides basic
|
|
|
server-side scaling. It is a global scaling of the desktop, not a
|
|
|
per-client setting. To enable it use the "[326]-scale fraction"
|
|
|
option. "fraction" can either be a floating point number (e.g. -scale
|
|
|
0.5) or the alternative m/n fraction notation (e.g. -scale 2/3). Note
|
|
|
that if fraction is greater than one the display is expanded (not
|
|
|
clear how useful that is...)
|
|
|
|
|
|
The current implementation is experimental in that it still needs to
|
|
|
be optimized. Extra resources (CPU, memory I/O, and memory) are
|
|
|
required to do the scaling. If the machine is slow where x11vnc is run
|
|
|
with scaling enabled, the interactive response can be unacceptable.
|
|
|
OTOH, if run with scaling on a fast machine the performance
|
|
|
degradation is usually not a big issue or even noticeable.
|
|
|
|
|
|
Also, if you just want a quick, rough "thumbnail" of the display you
|
|
|
can append ":nb" to the fraction to turn on "no blending" mode. E.g.:
|
|
|
"-scale 1/3:nb" Fonts will be difficult to read, but the larger
|
|
|
features will be recognizable. BTW, "no blending" mode is forced on
|
|
|
when scaling 8bpp PseudoColor displays (because blending an indexed
|
|
|
colormap is a bad idea and leads to random colors).
|
|
|
|
|
|
In general for a scaled display if you are using a TightVNC viewer you
|
|
|
may want to turn off jpeg encoding (e.g. vncviewer -nojpeg host:0).
|
|
|
There appears to be a noise enhancement effect, especially for regions
|
|
|
containing font/text: the scaling can introduce some pixel artifacts
|
|
|
that evidently causes the tight encoding algorithm to incorrectly
|
|
|
detect the regions as image data and thereby introduce additional
|
|
|
pixel artifacts due to the lossiness of the jpeg compression
|
|
|
algorithm. Experiment to see if -nojpeg vncviewer option improves the
|
|
|
readability of text when using -scale to shrink the display size. Also
|
|
|
note that scaling may actually slow down the transfer of text regions
|
|
|
because after being scaled they do not compress as well. (this can
|
|
|
often be a significant slowdown, e.g. 10X).
|
|
|
|
|
|
Another issue is that it appears VNC viewers require the screen width
|
|
|
to be a multiple of 4. When scaling x11vnc will round the width to the
|
|
|
nearest multiple of 4. To disable this use the ":n4" sub option (like
|
|
|
":nb" in the previous paragraph; to specify both use a comma:
|
|
|
":nb,n4", etc.)
|
|
|
|
|
|
If one desires per-client scaling for something like 1:1 from a
|
|
|
workstation and 1:2 from a smaller device (e.g. handheld), currently
|
|
|
the only option is to run two (or more) x11vnc processes with
|
|
|
different scalings listening on separate ports ([327]-rfbport option,
|
|
|
etc.).
|
|
|
|
|
|
Q-63: Does x11vnc work with Xinerama? (i.e. multiple monitors joined
|
|
|
together to form one big, single screen).
|
|
|
|
|
|
Yes, it should generally work because it simply polls the big
|
|
|
effective screen. If the viewing-end monitor is not as big as the
|
|
|
remote Xinerama display, then the vncviewer scrollbars, etc, will have
|
|
|
to be used to pan across the large area.
|
|
|
|
|
|
There are a couple potential issues however. If the screen is not
|
|
|
rectangular (e.g. 1280x1024 and 1024x768 monitors joined together),
|
|
|
then there will be "non-existent" areas on the screen. The X server
|
|
|
will return "garbage" image data for these areas and so they may be
|
|
|
distracting to the viewer. The [328]-blackout x11vnc option allows you
|
|
|
to blacken-out rectangles by specifying their WxH+X+Y geometries. If
|
|
|
your system has the libXinerama library, the [329]-xinerama x11vnc
|
|
|
option can be used to have it automatically determine the rectangles
|
|
|
to be blackened out. (Note on 8bpp PseudoColor displays the fill color
|
|
|
may not be black).
|
|
|
|
|
|
Some users have reported that the mouse does not behave properly for
|
|
|
their Xinerama display: i.e. the mouse cannot be moved to all regions
|
|
|
of the large display. If this happens try using the [330]-xwarppointer
|
|
|
option. This instructs x11vnc to fake mouse pointer motions using the
|
|
|
XWarpPointer function instead of the XTestFakeMotionEvent XTEST
|
|
|
function. (This may be due to a bug in the X server for XTEST when
|
|
|
Xinerama is enabled).
|
|
|
|
|
|
Q-64: Can I use x11vnc on a multi-headed display that is not Xinerama
|
|
|
(i.e. separate screens :0.0, :0.1, ... for each monitor)?
|
|
|
|
|
|
You can, but it is a little bit awkward: you must start separate
|
|
|
x11vnc processes for each screen, and on the viewing end start up
|
|
|
separate VNC viewer processes connecting to them. e.g. on the remote
|
|
|
end:
|
|
|
x11vnc -display :0.0 -bg -q -rfbport 5900
|
|
|
x11vnc -display :0.1 -bg -q -rfbport 5901
|
|
|
|
|
|
(this could be automated in the display manager Xsetup for example)
|
|
|
and then on the local machine where you are sitting:
|
|
|
vncviewer somehost:0 &
|
|
|
vncviewer somehost:1 &
|
|
|
|
|
|
Note: if you are running on Solaris 8 or earlier you can easily hit up
|
|
|
against the maximum of 6 shm segments per process (for Xsun in this
|
|
|
case) from running multiple x11vnc processes. You should modify
|
|
|
/etc/system as mentioned in another [331]FAQ to increase the limit. It
|
|
|
is probably also a good idea to run with the [332]-onetile option in
|
|
|
this case (to limit each x11vnc to 3 shm segments), or even
|
|
|
[333]-noshm to use no shm segments.
|
|
|
|
|
|
Q-65: Can x11vnc show only a portion of the display? (E.g. for a
|
|
|
special purpose rfb application).
|
|
|
|
|
|
As of Mar/2005 in the libvncserver CVS x11vnc has the "[334]-clip
|
|
|
WxH+X+Y" option to select a rectangle of width W, height H and offset
|
|
|
(X, Y). Thus the VNC screen will be the clipped sub-region of the
|
|
|
display and be only WxH in size.
|
|
|
|
|
|
This also works to view a sub-region of a single application window if
|
|
|
the [335]-id or [336]-sid options are used. The offset is measured
|
|
|
from the upper left corner of the selected window.
|
|
|
|
|
|
Q-66: Does x11vnc support the XRANDR (X Resize, Rotate and Reflection)
|
|
|
extension? Whenever I rotate or resize the screen x11vnc just seems to
|
|
|
crash.
|
|
|
|
|
|
As of Dec/2004 in the libvncserver CVS x11vnc supports XRANDR. You
|
|
|
enable it with the [337]-xrandr option to make x11vnc monitor XRANDR
|
|
|
events and also trap X server errors if the screen change occurred in
|
|
|
the middle of an X call like XGetImage. Once it traps the screen
|
|
|
change it will create a new framebuffer using the new screen. If the
|
|
|
connected vnc viewers support the NewFBSize VNC extension (Windows
|
|
|
TightVNC viewer and RealVNC 4.0 windows and Unix viewers do) then the
|
|
|
viewer will automatically resize. Otherwise, the new framebuffer is
|
|
|
fit as best as possible into the original viewer size (portions of the
|
|
|
screen may be clipped, unused, etc). For these viewers you can try the
|
|
|
[338]-padgeom option to make the region big enough to hold all resizes
|
|
|
and rotations.
|
|
|
|
|
|
If you specify "-xrandr newfbsize" then vnc viewers that do not
|
|
|
support NewFBSize will be disconnected before the resize. If you
|
|
|
specify "-xrandr exit" then all will be disconnected and x11vnc will
|
|
|
terminate.
|
|
|
|
|
|
Q-67: Why is the view in my VNC viewer completely black? Or why is
|
|
|
everything flashing around randomly?
|
|
|
|
|
|
See the next FAQ for a possible explanation.
|
|
|
|
|
|
Q-68: I use Linux Virtual Consoles (VC's) to implement 'Fast User
|
|
|
Switching' between users' sessions (e.g. Betty is on Ctrl-Alt-F7,
|
|
|
Bobby is on Ctrl-Alt-F8, and Sid is on Ctrl-Alt-F1: they use those
|
|
|
keystrokes to switch between their sessions). How come the view in a
|
|
|
VNC viewer connecting to x11vnc is either completely black or
|
|
|
otherwise all messed up unless the X session x11vnc is attached to is
|
|
|
in the active VC?
|
|
|
|
|
|
This seems to have to do with how applications (the X server processes
|
|
|
in this case) must "play nicely" if they are not on the active VC.
|
|
|
That is, they should not read from the keyboard or mouse or manage the
|
|
|
video display unless they have the active VC. Given that it appears
|
|
|
the XGetImage() call must ultimately retrieve the framebuffer data
|
|
|
from the video hardware itself, it would make sense x11vnc's polling
|
|
|
wouldn't work unless the X session had active control of the VC.
|
|
|
|
|
|
There does not seem to be an easy way to work around this. Even xwd(1)
|
|
|
doesn't work in this case (try it). Something would need to be done at
|
|
|
a lower level, say in the XFree86 X server. Also, using the XFree86
|
|
|
Shadow Framebuffer (a copy of the video framebuffer is kept in main
|
|
|
memory) does not appear to fix the problem.
|
|
|
|
|
|
If no one is sitting at the workstation and you just want to remotely
|
|
|
switch the VC over to the one associated with your X session (so
|
|
|
x11vnc can poll it correctly), one can use the switchto(1) command,
|
|
|
e.g. "switchto 7" for VC #7.
|
|
|
|
|
|
Q-69: I am using x11vnc where my local machine has "popup/hidden
|
|
|
taskbars" (e.g. GNOME or MacOS X) and the remote display where x11vnc
|
|
|
runs also has "popup/hidden taskbars" (e.g. GNOME). When I move the
|
|
|
mouse to the edge of the screen where the popups happen, the taskbars
|
|
|
interfere and fight with each other in strange ways. What can I do?
|
|
|
|
|
|
Is there a way to temporarily disable one or both of these magic
|
|
|
desktop taskbars? One x11vnc user suggests: it should be
|
|
|
straightforward to right mouse click on the task bar panel, and
|
|
|
uncheck "enable auto-hide" from the panel properties dialog box. This
|
|
|
will make the panel always visible.
|
|
|
|
|
|
[Misc: Clipboard, Beeps, Thanks, etc.]
|
|
|
|
|
|
Q-70: Does the Clipboard/Selection get transferred between the
|
|
|
vncviewer and the X display?
|
|
|
|
|
|
As of Jan/2004 in the libvncserver CVS x11vnc supports the "CutText"
|
|
|
part of the rfb protocol. Furthermore, x11vnc is able to hold the
|
|
|
PRIMARY selection (Xvnc does not seem to do this). If you don't want
|
|
|
the Clipboard/Selection exchanged use the [339]-nosel option. If you
|
|
|
don't want the PRIMARY selection to be polled for changes use the
|
|
|
[340]-noprimary option.
|
|
|
|
|
|
You may need to watch out for desktop utilities such as KDE's
|
|
|
"Klipper" that do odd things with the selection, clipboard, and
|
|
|
cutbuffers.
|
|
|
|
|
|
Q-71: Why don't I hear the "Beeps" in my X session (e.g. when typing
|
|
|
tput bel in an xterm)?
|
|
|
|
|
|
As of Dec/2003 in the libvncserver CVS "Beep" XBell events are tracked
|
|
|
by default. The X server must support the XKEYBOARD extension (this is
|
|
|
not on by default in Solaris, see Xserver(1) for how to turn it on via
|
|
|
+kb), and so you won't hear them if the extension is not present.
|
|
|
|
|
|
If you don't want to hear the beeps use the [341]-nobell option. If
|
|
|
you want to hear the audio from the remote applications, consider
|
|
|
trying a redirector such as esd.
|
|
|
|
|
|
Q-72: Thanks for your program and for your help! Can I make a
|
|
|
donation?
|
|
|
|
|
|
Please do (any amount is appreciated) and thank you for your support!
|
|
|
Click on the PayPal button below for more info.
|
|
|
Also, in general I always enjoy hearing from x11vnc users, how they
|
|
|
use it, what new features they would like, etc. Please send me an
|
|
|
[342]email!
|
|
|
|
|
|
[PayPal]
|
|
|
|
|
|
References
|
|
|
|
|
|
1. http://www.karlrunge.com/x11vnc/index.html#faq
|
|
|
2. http://www.karlrunge.com/x11vnc/index.html#downloading
|
|
|
3. http://www.karlrunge.com/x11vnc/index.html#building
|
|
|
4. http://www.karlrunge.com/x11vnc/index.html#faq
|
|
|
5. http://www.karlrunge.com/x11vnc/index.html#contact
|
|
|
6. http://www.uk.research.att.com/vnc/
|
|
|
7. http://www.realvnc.com/
|
|
|
8. http://www.tightvnc.com/
|
|
|
9. http://www.karlrunge.com/x11vnc/index.html#downloading
|
|
|
10. http://www.tightvnc.com/download.html
|
|
|
11. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-auth
|
|
|
12. http://www.karlrunge.com/x11vnc/index.html#faq-xperms
|
|
|
13. http://www.karlrunge.com/x11vnc/index.html#faq-viewer-download
|
|
|
14. http://www.sun.com/software/solaris/freeware/
|
|
|
15. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-forever
|
|
|
16. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-forever
|
|
|
17. http://www.karlrunge.com/x11vnc/index.html#faq-service
|
|
|
18. http://www.karlrunge.com/x11vnc/index.html#faq-passwd
|
|
|
19. http://www.karlrunge.com/x11vnc/index.html#vnc_password_file
|
|
|
20. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-connect
|
|
|
21. http://www.karlrunge.com/x11vnc/index.html#faq-inetd
|
|
|
22. http://www.karlrunge.com/x11vnc/index.html#tightvnc_via
|
|
|
23. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-bg
|
|
|
24. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-connect
|
|
|
25. http://www.karlrunge.com/x11vnc/index.html#faq-inetd
|
|
|
26. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-rfbauth
|
|
|
27. http://www.karlrunge.com/x11vnc/index.html#faq-passwd
|
|
|
28. http://www.karlrunge.com/x11vnc/index.html#faq-passwdfile
|
|
|
29. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-passwdfile
|
|
|
30. http://www.karlrunge.com/x11vnc/index.html#faq-allow-opt
|
|
|
31. http://www.karlrunge.com/x11vnc/index.html#faq-tcp_wrappers
|
|
|
32. http://sourceforge.net/projects/libvncserver/
|
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|
33. http://sourceforge.net/project/showfiles.php?group_id=32584&package_id=119006&release_id=307884
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34. http://sourceforge.net/project/shownotes.php?group_id=32584&release_id=307884
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35. http://www.karlrunge.com/x11vnc/x11vnc.c
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36. http://www.karlrunge.com/x11vnc/tkx11vnc.h
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37. http://www.karlrunge.com/x11vnc/index.html#faq-binaries
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38. http://www.tightvnc.com/download.html
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39. http://www.realvnc.com/download-free.html
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40. http://sourceforge.net/projects/cotvnc/
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41. http://www.karlrunge.com/x11vnc/rx11vnc
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42. http://www.karlrunge.com/x11vnc/rx11vnc.pl
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43. http://www.sunfreeware.com/
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44. ftp://ftp.uu.net/graphics/jpeg/
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45. http://www.gzip.org/zlib/
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46. http://www.sunfreeware.com/
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47. http://www.karlrunge.com/x11vnc/index.html#faq-solaris251build
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48. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-solid
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49. http://www.tightvnc.com/
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50. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-rfbport
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51. http://www.karlrunge.com/x11vnc/x11vnc_opts.html
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52. http://www.karlrunge.com/x11vnc/index.html#faq-passwd
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53. http://www.karlrunge.com/x11vnc/recurse_x11vnc.jpg
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54. http://wwws.sun.com/sunray/index.html
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55. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-nap
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56. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-wait
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57. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-rfbport
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58. http://www.karlrunge.com/x11vnc/shm_clear
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59. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-cursor
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60. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-overlay
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61. mailto:xvml@karlrunge.com
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62. http://www.karlrunge.com/x11vnc/index.html#faq-thanks
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63. http://www.karlrunge.com/x11vnc/index.html#faq-xperms
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64. http://www.karlrunge.com/x11vnc/index.html#faq-build
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65. http://www.karlrunge.com/x11vnc/index.html#faq-solaris251build
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66. http://www.karlrunge.com/x11vnc/index.html#faq-binaries
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67. http://www.karlrunge.com/x11vnc/index.html#faq-viewer-download
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68. http://www.karlrunge.com/x11vnc/index.html#faq-cmdline-opts
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69. http://www.karlrunge.com/x11vnc/index.html#faq-config-file
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70. http://www.karlrunge.com/x11vnc/index.html#faq-quiet-bg
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71. http://www.karlrunge.com/x11vnc/index.html#faq-sigpipe
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72. http://www.karlrunge.com/x11vnc/index.html#faq-win2vnc
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73. http://www.karlrunge.com/x11vnc/index.html#faq-win2vnc-8bpp
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74. http://www.karlrunge.com/x11vnc/index.html#faq-8bpp
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75. http://www.karlrunge.com/x11vnc/index.html#faq-overlays
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76. http://www.karlrunge.com/x11vnc/index.html#faq-windowid
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77. http://www.karlrunge.com/x11vnc/index.html#faq-transients-id
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78. http://www.karlrunge.com/x11vnc/index.html#faq-24bpp
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79. http://www.karlrunge.com/x11vnc/index.html#faq-noshm
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80. http://www.karlrunge.com/x11vnc/index.html#faq-xterminal-xauth
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81. http://www.karlrunge.com/x11vnc/index.html#faq-stop-bg
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82. http://www.karlrunge.com/x11vnc/index.html#faq-remote_control
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83. http://www.karlrunge.com/x11vnc/index.html#faq-passwd
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84. http://www.karlrunge.com/x11vnc/index.html#faq-passwdfile
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85. http://www.karlrunge.com/x11vnc/index.html#faq-input-opt
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86. http://www.karlrunge.com/x11vnc/index.html#faq-forever-shared
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87. http://www.karlrunge.com/x11vnc/index.html#faq-allow-opt
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88. http://www.karlrunge.com/x11vnc/index.html#faq-tcp_wrappers
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89. http://www.karlrunge.com/x11vnc/index.html#faq-listen-interface
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90. http://www.karlrunge.com/x11vnc/index.html#faq-listen-localhost
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91. http://www.karlrunge.com/x11vnc/index.html#faq-ssh-unix
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92. http://www.karlrunge.com/x11vnc/index.html#faq-ssh-putty
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93. http://www.karlrunge.com/x11vnc/index.html#faq-accept-opt
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94. http://www.karlrunge.com/x11vnc/index.html#faq-unix-passwords
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95. http://www.karlrunge.com/x11vnc/index.html#faq-users-opt
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96. http://www.karlrunge.com/x11vnc/index.html#faq-blockdpy
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97. http://www.karlrunge.com/x11vnc/index.html#faq-gone-lock
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98. http://www.karlrunge.com/x11vnc/index.html#faq-service
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99. http://www.karlrunge.com/x11vnc/index.html#faq-display-manager
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100. http://www.karlrunge.com/x11vnc/index.html#faq-inetd
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101. http://www.karlrunge.com/x11vnc/index.html#faq-java-http
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102. http://www.karlrunge.com/x11vnc/index.html#faq-reverse-connect
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103. http://www.karlrunge.com/x11vnc/index.html#faq-solshm
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104. http://www.karlrunge.com/x11vnc/index.html#faq-less-resource
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105. http://www.karlrunge.com/x11vnc/index.html#faq-more-resource
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106. http://www.karlrunge.com/x11vnc/index.html#faq-slow-link
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107. http://www.karlrunge.com/x11vnc/index.html#faq-pointer-mode
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108. http://www.karlrunge.com/x11vnc/index.html#faq-xdamage
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109. http://www.karlrunge.com/x11vnc/index.html#faq-cursor-shape
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110. http://www.karlrunge.com/x11vnc/index.html#faq-xfixes-alpha
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111. http://www.karlrunge.com/x11vnc/index.html#faq-xfixes-alpha-hacks
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112. http://www.karlrunge.com/x11vnc/index.html#faq-cursor-arrow
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113. http://www.karlrunge.com/x11vnc/index.html#faq-cursor-positions
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114. http://www.karlrunge.com/x11vnc/index.html#faq-buttonmap-opt
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115. http://www.karlrunge.com/x11vnc/index.html#faq-altgr
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116. http://www.karlrunge.com/x11vnc/index.html#faq-greaterless
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117. http://www.karlrunge.com/x11vnc/index.html#faq-xkbmodtweak
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118. http://www.karlrunge.com/x11vnc/index.html#faq-repeated-keys
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119. http://www.karlrunge.com/x11vnc/index.html#faq-repeated-keys-still
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120. http://www.karlrunge.com/x11vnc/index.html#faq-remap-opt
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121. http://www.karlrunge.com/x11vnc/index.html#faq-sun-alt-meta
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122. http://www.karlrunge.com/x11vnc/index.html#faq-remap-button-click
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123. http://www.karlrunge.com/x11vnc/index.html#faq-scrollbars
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124. http://www.karlrunge.com/x11vnc/index.html#faq-scaling
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125. http://www.karlrunge.com/x11vnc/index.html#faq-xinerama
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126. http://www.karlrunge.com/x11vnc/index.html#faq-multi-screen
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127. http://www.karlrunge.com/x11vnc/index.html#faq-clip-screen
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128. http://www.karlrunge.com/x11vnc/index.html#faq-xrandr
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129. http://www.karlrunge.com/x11vnc/index.html#faq-black-screen
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130. http://www.karlrunge.com/x11vnc/index.html#faq-linuxvc
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131. http://www.karlrunge.com/x11vnc/index.html#faq-hidden-taskbars
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132. http://www.karlrunge.com/x11vnc/index.html#faq-clipboard
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133. http://www.karlrunge.com/x11vnc/index.html#faq-beeps
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134. http://www.karlrunge.com/x11vnc/index.html#faq-thanks
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135. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-display
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136. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-auth
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137. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-users
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138. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-auth
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139. http://www.karlrunge.com/x11vnc/index.html#solarisbuilding
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140. http://www.karlrunge.com/x11vnc/x11vnc_sunos4.html
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141. http://www.karlrunge.com/x11vnc/index.html#building
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142. http://www.karlrunge.com/x11vnc/index.html#faq-build
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143. http://packages.debian.org/x11vnc
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144. http://www.linuxpackages.net/search_view.php?by=name&name=x11vnc
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145. http://dag.wieers.com/packages/x11vnc/
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146. http://www.sunfreeware.com/
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147. http://www.bell-labs.com/project/wwexptools/packages.html
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148. http://www.karlrunge.com/x11vnc/index.html#solarisbuilding
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149. http://www.karlrunge.com/x11vnc/bins
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150. http://www.tightvnc.com/download.html
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151. http://www.realvnc.com/download-free.html
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152. http://sourceforge.net/projects/cotvnc/
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153. http://www.karlrunge.com/x11vnc/x11vnc_opts.html
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154. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-gui
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155. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-q
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156. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-bg
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157. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-o
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158. http://www.karlrunge.com/x11vnc/x11vnc.c
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159. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-sigpipe
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160. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-nofb
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161. http://fredrik.hubbe.net/x2vnc.html
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162. http://www.hubbe.net/~hubbe/win2vnc.html
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163. http://www.deboer.gmxhome.de/
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164. http://sourceforge.net/projects/win2vnc/
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165. http://fredrik.hubbe.net/x2vnc.html
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166. http://freshmeat.net/projects/x2x/
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167. http://ftp.digital.com/pub/Digital/SRC/x2x/
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168. http://zapek.com/software/zvnc/
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169. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-visual
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170. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-flashcmap
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171. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-notruecolor
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172. http://www.karlrunge.com/x11vnc/index.html#faq-8bpp
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173. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-overlay
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174. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-overlay
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175. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-id
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176. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-overlay
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177. http://www.karlrunge.com/x11vnc/index.html#faq-overlays
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178. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-id
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179. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-sid
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180. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-display
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181. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-noshm
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182. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-flipbyteorder
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183. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-auth
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184. http://www.karlrunge.com/x11vnc/index.html#xauth_pain
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185. http://www.karlrunge.com/x11vnc/index.html#faq-noshm
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186. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-remote
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187. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-query
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188. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-forever
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189. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-bg
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190. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-clear_mods
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191. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-clear_keys
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192. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-remote
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193. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-query
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194. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-gui
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195. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-storepasswd
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196. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-rfbauth
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197. http://www.karlrunge.com/x11vnc/index.html#faq-passwdfile
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198. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-viewpasswd
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199. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-passwd
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200. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-passwdfile
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201. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-rfbauth
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202. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-input
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203. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-forever
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204. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-shared
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205. http://www.karlrunge.com/x11vnc/index.html#tunnelling
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206. http://www.karlrunge.com/x11vnc/index.html#faq-passwd
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207. http://www.karlrunge.com/x11vnc/index.html#faq-passwdfile
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208. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-allow
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209. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-localhost
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210. http://www.karlrunge.com/x11vnc/index.html#faq-tcp_wrappers
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211. http://www.karlrunge.com/x11vnc/index.html#faq-inetd
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212. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-listen
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213. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-allow
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214. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-localhost
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215. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-allow
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216. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-localhost
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217. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-listen
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218. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-allow
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219. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-localhost
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220. http://www.karlrunge.com/x11vnc/index.html#tunnelling
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221. http://www.karlrunge.com/x11vnc/index.html#tunnelling
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222. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-localhost
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223. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-rfbauth
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224. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-passwdfile
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225. http://www.karlrunge.com/x11vnc/index.html#tunnelling
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226. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-connect
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227. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-accept
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228. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-viewonly
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229. ftp://ftp.x.org/
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230. http://www.karlrunge.com/x11vnc/dtVncPopup
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231. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-gone
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232. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-localhost
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233. http://www.karlrunge.com/x11vnc/index.html#tunnelling
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234. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-accept
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235. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-users
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236. http://www.karlrunge.com/x11vnc/blockdpy.c
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237. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-accept
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238. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-gone
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239. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-gone
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240. http://www.karlrunge.com/x11vnc/index.html#faq-display-manager
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241. http://www.karlrunge.com/x11vnc/index.html#faq-inetd
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242. http://www.karlrunge.com/x11vnc/index.html#x11vnc_loop
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243. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-auth
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244. http://www.karlrunge.com/x11vnc/index.html#dtlogin_solaris
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245. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-o
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246. http://www.jirka.org/gdm-documentation/x241.html
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247. http://www.karlrunge.com/x11vnc/x11vnc_loop
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|
|
248. http://www.karlrunge.com/x11vnc/index.html#faq-xterminal-xauth
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249. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-inetd
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250. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-q
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251. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-auth
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252. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-httpdir
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253. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-connect
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254. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-vncconnect
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255. http://www.karlrunge.com/x11vnc/shm_clear
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256. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-onetile
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257. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-noshm
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258. http://www.karlrunge.com/x11vnc/index.html#faq-noshm
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259. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-nap
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|
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260. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-wait
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|
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261. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-onetile
|
|
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262. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-fs
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263. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-threads
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264. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-defer
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265. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-id
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|
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266. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-solid
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267. http://www.tightvnc.com/
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268. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-nodragging
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269. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-progressive
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270. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-fs
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271. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-wait
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|
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272. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-defer
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273. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-id
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274. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-nosel
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275. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-nocursor
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|
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276. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-nocursorpos
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277. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-pointer_mode
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|
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278. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-nodragging
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|
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279. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-pointer_mode
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|
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280. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-threads
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|
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281. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-xd_area
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|
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282. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-xd_mem
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|
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283. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-noxdamage
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|
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284. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-cursor
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|
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285. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-cursor
|
|
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286. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-overlay
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|
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287. http://www.karlrunge.com/x11vnc/index.html#the-overlay-mode
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|
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288. http://www.karlrunge.com/x11vnc/index.html#solaris10-build
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|
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289. http://www.karlrunge.com/x11vnc/index.html#faq-xfixes-alpha-hacks
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290. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-alphacut
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291. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-alphafrac
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|
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292. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-alpharemove
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|
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293. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-nocursorshape
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294. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-noalphablend
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|
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295. http://www.tightvnc.com/
|
|
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296. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-nocursor
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|
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297. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-cursorpos
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|
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298. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-nocursorpos
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|
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299. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-nocursorshape
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|
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300. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-buttonmap
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|
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301. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-debug_pointer
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|
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302. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-buttonmap
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|
|
303. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-modtweak
|
|
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304. http://www.karlrunge.com/x11vnc/index.html#faq-greaterless
|
|
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305. http://www.karlrunge.com/x11vnc/index.html#faq-xkbmodtweak
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|
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306. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-debug_keyboard
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|
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307. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-modtweak
|
|
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308. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-remap
|
|
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309. http://www.karlrunge.com/x11vnc/index.html#faq-xkbmodtweak
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|
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310. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-debug_keyboard
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|
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311. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-modtweak
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|
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312. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-xkb
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|
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313. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-skip_keycodes
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|
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314. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-remap
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315. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-add_keysyms
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|
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316. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-remap
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|
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317. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-add_keysyms
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|
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318. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-norepeat
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|
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319. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-norepeat
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|
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320. http://www.karlrunge.com/x11vnc/index.html#faq-display-manager
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|
|
321. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-remap
|
|
|
322. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-remap
|
|
|
323. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-remap
|
|
|
324. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-remap
|
|
|
325. http://www.karlrunge.com/x11vnc/index.html#faq-scaling
|
|
|
326. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-scale
|
|
|
327. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-rfbport
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|
|
328. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-blackout
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|
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329. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-xinerama
|
|
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330. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-xwarppointer
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|
|
331. http://www.karlrunge.com/x11vnc/index.html#faq-solshm
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|
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332. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-onetile
|
|
|
333. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-noshm
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|
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334. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-clip
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|
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335. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-id
|
|
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336. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-id
|
|
|
337. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-xrandr
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|
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338. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-padgeom
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|
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339. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-nosel
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|
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340. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-noprimary
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|
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341. http://www.karlrunge.com/x11vnc/x11vnc_opts.html#opt-nobell
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342. mailto:xvml@karlrunge.com
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|
=======================================================================
|
|
|
http://www.karlrunge.com/x11vnc/x11vnc_opts.html:
|
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|
|
|
_________________________________________________________________
|
|
|
|
|
|
x11vnc: a VNC server for real X displays
|
|
|
|
|
|
Here are all of x11vnc command line options:
|
|
|
% x11vnc -opts (see below for -help long descriptions)
|
|
|
|
|
|
x11vnc: allow VNC connections to real X11 displays. 0.7.2pre lastmod: 2005-03-1
|
|
|
2
|
|
|
|
|
|
x11vnc options:
|
|
|
-display disp -auth file
|
|
|
-id windowid -sid windowid
|
|
|
-clip WxH+X+Y -flashcmap
|
|
|
-notruecolor -visual n
|
|
|
-overlay -overlay_nocursor
|
|
|
-scale fraction -viewonly
|
|
|
-shared -once
|
|
|
-forever -timeout n
|
|
|
-inetd -connect string
|
|
|
-vncconnect -novncconnect
|
|
|
-allow host1[,host2..] -localhost
|
|
|
-input string -viewpasswd string
|
|
|
-passwdfile filename -storepasswd pass file
|
|
|
-accept string -gone string
|
|
|
-users list -noshm
|
|
|
-flipbyteorder -onetile
|
|
|
-solid [color] -blackout string
|
|
|
-xinerama -xrandr [mode]
|
|
|
-padgeom WxH -o logfile
|
|
|
-rc filename -norc
|
|
|
-h, -help -?, -opts
|
|
|
-V, -version -q
|
|
|
-bg -modtweak
|
|
|
-nomodtweak -xkb
|
|
|
-skip_keycodes string -add_keysyms
|
|
|
-clear_mods -clear_keys
|
|
|
-remap string -norepeat
|
|
|
-repeat -nofb
|
|
|
-nobell -nosel
|
|
|
-noprimary -cursor [mode]
|
|
|
-nocursor -noxfixes
|
|
|
-alphacut n -alphafrac fraction
|
|
|
-alpharemove -noalphablend
|
|
|
-nocursorshape -cursorpos
|
|
|
-nocursorpos -xwarppointer
|
|
|
-buttonmap string -nodragging
|
|
|
-pointer_mode n -input_skip n
|
|
|
-speeds rd,bw,lat -debug_pointer
|
|
|
-debug_keyboard -defer time
|
|
|
-wait time -nap
|
|
|
-nonap -sb time
|
|
|
-noxdamage -xd_area A
|
|
|
-xd_mem f -sigpipe string
|
|
|
-threads -nothreads
|
|
|
-fs f -gaps n
|
|
|
-grow n -fuzz n
|
|
|
-snapfb -gui [gui-opts]
|
|
|
-remote command -query variable
|
|
|
-sync -noremote
|
|
|
-unsafe -safer
|
|
|
-deny_all
|
|
|
|
|
|
libvncserver options:
|
|
|
-rfbport port TCP port for RFB protocol
|
|
|
-rfbwait time max time in ms to wait for RFB client
|
|
|
-rfbauth passwd-file use authentication on RFB protocol
|
|
|
(use 'storepasswd' to create a password file)
|
|
|
-passwd plain-password use authentication
|
|
|
(use plain-password as password, USE AT YOUR RISK)
|
|
|
-deferupdate time time in ms to defer updates (default 40)
|
|
|
-desktop name VNC desktop name (default "LibVNCServer")
|
|
|
-alwaysshared always treat new clients as shared
|
|
|
-nevershared never treat new clients as shared
|
|
|
-dontdisconnect don't disconnect existing clients when a new non-shared
|
|
|
connection comes in (refuse new connection instead)
|
|
|
-httpdir dir-path enable http server using dir-path home
|
|
|
-httpport portnum use portnum for http connection
|
|
|
-enablehttpproxy enable http proxy support
|
|
|
-progressive height enable progressive updating for slow links
|
|
|
-listen ipaddr listen for connections only on network interface with
|
|
|
addr ipaddr. '-listen localhost' and hostname work too.
|
|
|
|
|
|
|
|
|
|
|
|
% x11vnc -help
|
|
|
|
|
|
x11vnc: allow VNC connections to real X11 displays. 0.7.2pre lastmod: 2005-03-1
|
|
|
2
|
|
|
|
|
|
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 on how to tunnel the VNC connection through
|
|
|
an encrypted channel such as ssh(1).
|
|
|
|
|
|
For additional info see: http://www.karlrunge.com/x11vnc/
|
|
|
and http://www.karlrunge.com/x11vnc/#faq
|
|
|
|
|
|
|
|
|
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 "-wait 100" are acceptable and equivalent lines.
|
|
|
The "#" character comments out to the end of the line in the usual way.
|
|
|
Leading and trailing whitespace is trimmed off. Lines may be continued with
|
|
|
a "\" as the last character of a line (it becomes a space character).
|
|
|
|
|
|
Options:
|
|
|
|
|
|
-display disp 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".
|
|
|
-auth file 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.
|
|
|
|
|
|
-id windowid 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 "-id pick"
|
|
|
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).
|
|
|
-sid windowid 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.
|
|
|
-clip WxH+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).
|
|
|
-notruecolor For 8bpp displays, force indexed color (i.e. a colormap)
|
|
|
even if it looks like 8bpp TrueColor (rare problem).
|
|
|
-visual n 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" the 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). Also note that the mouse
|
|
|
cursor shape is exactly correct in this mode.
|
|
|
|
|
|
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 messed
|
|
|
up 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 degraded
|
|
|
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.
|
|
|
|
|
|
-scale fraction 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. Currently the cursor shape is not scaled.
|
|
|
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). For compatibility with vncviewers the scaled
|
|
|
width is adjusted to be a multiple of 4: to disable
|
|
|
this use ":n4". More esoteric options: ":in" use
|
|
|
interpolation scheme even when shrinking, ":pad",
|
|
|
pad scaled width and height to be multiples of scaling
|
|
|
denominator (e.g. 3 for 2/3).
|
|
|
|
|
|
-viewonly All VNC clients can only watch (default off).
|
|
|
-shared VNC display is shared (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
|
|
|
-timeout n Exit unless a client connects within the first n seconds
|
|
|
of startup.
|
|
|
-inetd Launched by inetd(1): 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.
|
|
|
-connect string 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.
|
|
|
|
|
|
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 inetd(1) or gdm(1)).
|
|
|
-vncconnect Monitor the VNC_CONNECT X property set by the standard
|
|
|
-novncconnect 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). Default: -vncconnect
|
|
|
|
|
|
-allow host1[,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 Same as "-allow 127.0.0.1".
|
|
|
|
|
|
Note: if you want to restrict which network interface
|
|
|
x11vnc listens on, see the -listen option below.
|
|
|
E.g. "-listen localhost" or "-listen 192.168.3.21".
|
|
|
As a special case, the option "-localhost" implies
|
|
|
"-listen localhost".
|
|
|
|
|
|
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.
|
|
|
|
|
|
-input string 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, and "B" for Button-click input.
|
|
|
Their presence in the string enables that type of input.
|
|
|
E.g. "-input M" means normal users can only move
|
|
|
the mouse and "-input KMB,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).
|
|
|
-viewpasswd string Supply a 2nd password for view-only logins. The -passwd
|
|
|
(full-access) password must also be supplied.
|
|
|
-passwdfile filename Specify libvncserver -passwd via the first line of the
|
|
|
file "filename" instead of via command line (where
|
|
|
others might see it via ps(1)). If a second non blank
|
|
|
line exists in the file it is taken as a view-only
|
|
|
password (i.e. -viewpasswd) To supply an empty password
|
|
|
for either field the string "__EMPTY__" may be used.
|
|
|
Note: -passwdfile is a simple plaintext passwd, see
|
|
|
also -rfbauth and -storepasswd below for obfuscated
|
|
|
VNC password files. Neither file should be readable
|
|
|
by others.
|
|
|
-storepasswd pass file Store password "pass" as the VNC password in the
|
|
|
file "file". Once the password is stored the
|
|
|
program exits. Use the password via "-rfbauth file"
|
|
|
-accept string 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(1) 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"
|
|
|
|
|
|
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)
|
|
|
|
|
|
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).
|
|
|
|
|
|
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.
|
|
|
-gone string 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. Unlike -accept, the command return code
|
|
|
is not interpreted by x11vnc. Example: -gone 'xlock &'
|
|
|
|
|
|
-users list If x11vnc is started as root (say from inetd(1) 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 "-solid color" feature
|
|
|
external commands (gconftool-2 and dcop) 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 many situations
|
|
|
its use can decrease security.
|
|
|
|
|
|
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: "-users fred,wilma,betty".
|
|
|
Note that a malicious user "barney" by quickly using
|
|
|
"xhost +" when logging in may get x11vnc 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 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.
|
|
|
|
|
|
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 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:
|
|
|
"-users guess=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. Examples: "-users lurk=" and also
|
|
|
"-users lurk=: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(1) 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:".
|
|
|
-blackout string Black out rectangles on the screen. "string" is a
|
|
|
comma separated list of WxH+X+Y type geometries for
|
|
|
each rectangle.
|
|
|
-xinerama If your screen is composed of multiple monitors
|
|
|
glued together via XINERAMA, and that screen is
|
|
|
non-rectangular this option will try to guess the
|
|
|
areas to black out (if your system has libXinerama).
|
|
|
|
|
|
In general on XINERAMA displays you may need to use the
|
|
|
-xwarppointer option if the mouse pointer misbehaves.
|
|
|
|
|
|
-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.
|
|
|
-padgeom WxH 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.)
|
|
|
|
|
|
-o logfile Write stderr messages to file "logfile" instead of
|
|
|
to the terminal. Same as "-logfile file". To append
|
|
|
to the file use "-oa file" or "-logappend file".
|
|
|
-rc filename Use "filename" instead of $HOME/.x11vncrc for rc file.
|
|
|
-norc Do not process any .x11vncrc file for options.
|
|
|
-h, -help Print this help text.
|
|
|
-?, -opts Only list the x11vnc options.
|
|
|
-V, -version Print program version and last modification date.
|
|
|
|
|
|
-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:
|
|
|
port=`ssh $host "x11vnc -display :0 -bg" | grep PORT`
|
|
|
port=`echo "$port" | sed -e 's/PORT=//'`
|
|
|
port=`expr $port - 5900`
|
|
|
vncviewer $host:$port
|
|
|
|
|
|
-modtweak Option -modtweak automatically tries to adjust the AltGr
|
|
|
-nomodtweak 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 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.
|
|
|
-skip_keycodes string 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_keycodes 94,114"
|
|
|
-add_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.
|
|
|
Added Keysyms will be removed when x11vnc exits.
|
|
|
-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.
|
|
|
-remap string 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: "-remap Super_R-Button2"
|
|
|
(useful for pasting on a laptop)
|
|
|
-norepeat Option -norepeat disables X server key auto repeat
|
|
|
-repeat when VNC clients are connected. This works around a
|
|
|
repeating keystrokes bug (triggered by long processing
|
|
|
delays between key down and key up client events:
|
|
|
either from large screen changes or high latency).
|
|
|
Note: your VNC viewer side will likely do autorepeating,
|
|
|
so this is no loss unless someone is simultaneously at
|
|
|
the real X display. Default: -norepeat
|
|
|
|
|
|
-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.
|
|
|
-noprimary Do not poll the PRIMARY selection for changes to send
|
|
|
back to clients. (PRIMARY is still set on received
|
|
|
changes, however).
|
|
|
|
|
|
-cursor [mode] Sets how the pointer cursor shape (little icon at the
|
|
|
-nocursor 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_nomouse 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 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:
|
|
|
|
|
|
"-cursor arrow" - just show the standard arrow
|
|
|
nothing more or nothing less.
|
|
|
|
|
|
"-cursor none" - same as "-nocursor"
|
|
|
|
|
|
"-cursor X" - 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.
|
|
|
|
|
|
"-cursor some" - 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.
|
|
|
|
|
|
"-cursor most" - 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.
|
|
|
|
|
|
-noxfixes Do not use the XFIXES extension to draw the exact cursor
|
|
|
shape even if it is available.
|
|
|
-alphacut n When using the XFIXES extension for the cursor shape,
|
|
|
cursors with transparency will not 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
|
|
|
|
|
|
Note: the options -alphacut, -alphafrac, and -alphafrac
|
|
|
may be removed if a more accurate internal method for
|
|
|
handling cursor transparency is implemented.
|
|
|
-alphafrac fraction 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 Option -cursorpos enables sending the X cursor position
|
|
|
-nocursorpos 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.
|
|
|
|
|
|
-buttonmap string 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
|
|
|
-pointer_mode n 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. 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.
|
|
|
|
|
|
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_skip n 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
|
|
|
|
|
|
-speeds rd,bw,lat x11vnc tries to estimate some speed parameters that
|
|
|
are used to optimize scheduling (e.g. -pointer_mode
|
|
|
4) 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, 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 to clients. For the latency the ping(1)
|
|
|
command can be used.
|
|
|
|
|
|
For convenience there are some aliases provided,
|
|
|
e.g. "-speeds modem". The aliases are: "modem" for
|
|
|
6,4,200; "dsl" for 6,100,50; and "lan" for 6,5000,1
|
|
|
|
|
|
-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.
|
|
|
|
|
|
-defer time Time in ms to wait for updates before sending to client
|
|
|
(deferUpdateTime) Default: 30
|
|
|
-wait time Time in ms to pause between screen polls. Used to cut
|
|
|
down on load. Default: 30
|
|
|
-nap Monitor activity and if it is low take longer naps
|
|
|
-nonap between screen polls to really cut down load when idle.
|
|
|
Default: take naps
|
|
|
-sb time 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
|
|
|
|
|
|
-noxdamage Do not use the X DAMAGE extension to detect framebuffer
|
|
|
changes even if it is available.
|
|
|
|
|
|
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_area A 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_mem f 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).
|
|
|
|
|
|
-sigpipe string 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".
|
|
|
-threads Whether or not to use the threaded libvncserver
|
|
|
-nothreads algorithm [rfbRunEventLoop] if libpthread is available
|
|
|
Default: -nothreads
|
|
|
|
|
|
-fs f If the fraction of changed tiles in a poll is greater
|
|
|
than f, the whole screen is updated. Default: 0.75
|
|
|
-gaps n Heuristic to fill in gaps in rows or cols of n or
|
|
|
less tiles. Used to improve text paging. Default: 4
|
|
|
-grow n Heuristic to grow islands of changed tiles n or wider
|
|
|
by checking the tile near the boundary. Default: 3
|
|
|
-fuzz n Tolerance in pixels to mark a tiles edges as changed.
|
|
|
Default: 2
|
|
|
-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
|
|
|
(many) 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.
|
|
|
|
|
|
-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 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", and 3) the X display the gui
|
|
|
should display on.
|
|
|
|
|
|
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).
|
|
|
|
|
|
Examples: "x11vnc -gui", "x11vnc -gui ez"
|
|
|
"x11vnc -gui localhost:10", "x11vnc -gui conn,host:0"
|
|
|
|
|
|
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 connect to, 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
|
|
|
|
|
|
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.
|
|
|
|
|
|
-remote command 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 VNC_CONNECT), and so this
|
|
|
command must be run with correct settings for DISPLAY
|
|
|
and possibly XAUTHORITY to connect to the X server
|
|
|
and set the property. Alternatively, use the -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.
|
|
|
|
|
|
Note: the more drastic the change induced by the -remote
|
|
|
command, the bigger the chance for bugs or crashes.
|
|
|
Please report reproducible bugs.
|
|
|
|
|
|
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"
|
|
|
clip:WxH+X+Y set -clip mode to "WxH+X+Y"
|
|
|
flashcmap enable -flashcmap mode.
|
|
|
noflashcmap disable -flashcmap mode.
|
|
|
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.
|
|
|
visual:vis set -visual to "vis"
|
|
|
scale:frac set -scale to "frac"
|
|
|
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.
|
|
|
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.
|
|
|
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 -query clients 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.
|
|
|
input:str set -input to "str", empty to disable.
|
|
|
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).
|
|
|
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.
|
|
|
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.
|
|
|
quiet enable -quiet mode.
|
|
|
noquiet disable -quiet mode.
|
|
|
modtweak enable -modtweak mode.
|
|
|
nomodtweak enable -nomodtweak mode.
|
|
|
xkb enable -xkb modtweak mode.
|
|
|
noxkb disable -xkb modtweak mode.
|
|
|
skip_keycodes:str enable -xkb -skip_keycodes "str".
|
|
|
add_keysyms enable -add_keysyms mode.
|
|
|
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.
|
|
|
cursor:mode enable -cursor "mode".
|
|
|
show_cursor enable showing a cursor.
|
|
|
noshow_cursor disable showing a cursor. (same as
|
|
|
"nocursor")
|
|
|
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.
|
|
|
pointer_mode:n set -pointer_mode to n. same as "pm"
|
|
|
input_skip:n set -input_skip to n.
|
|
|
speeds:str set -speeds to str.
|
|
|
debug_pointer enable -debug_pointer, same as "dp"
|
|
|
nodebug_pointer disable -debug_pointer, same as "nodp"
|
|
|
debug_keyboard enable -debug_keyboard, same as "dk"
|
|
|
nodebug_keyboard disable -debug_keyboard, same as "nodk"
|
|
|
defer:n set -defer to n ms,same as deferupdate:n
|
|
|
wait:n set -wait to n ms.
|
|
|
rfbwait:n set -rfbwait (rfbMaxClientWait) to n ms.
|
|
|
nap enable -nap mode.
|
|
|
nonap disable -nap mode.
|
|
|
sb:n set -sb to n s, same as screen_blank:n
|
|
|
xdamage enable xdamage polling hints.
|
|
|
noxdamage disable xdamage polling hints.
|
|
|
xd_area:A set -xd_area max pixel area to "A"
|
|
|
xd_mem:f set -xd_mem remembrance to "f"
|
|
|
fs:frac set -fs fraction to "frac", e.g. 0.5
|
|
|
gaps:n set -gaps to n.
|
|
|
grow:n set -grow to n.
|
|
|
fuzz:n set -fuzz to n.
|
|
|
snapfb enable -snapfb mode.
|
|
|
nosnapfb disable -snapfb mode.
|
|
|
progressive:n set libvncserver -progressive slice
|
|
|
height parameter to n.
|
|
|
desktop:str set -desktop name to str for new clients
|
|
|
.
|
|
|
rfbport:n set -rfbport to n.
|
|
|
http enable http client connections.
|
|
|
nohttp disable http client connections.
|
|
|
httpport:n set -httpport to n.
|
|
|
httpdir:dir set -httpdir to dir (and enable http).
|
|
|
enablehttpproxy enable -enablehttpproxy mode.
|
|
|
noenablehttpproxy disable -enablehttpproxy mode.
|
|
|
alwaysshared enable -alwaysshared mode.
|
|
|
noalwaysshared disable -alwaysshared mode.
|
|
|
(may interfere with other options)
|
|
|
nevershared enable -nevershared mode.
|
|
|
nonevershared disable -nevershared mode.
|
|
|
(may interfere with other options)
|
|
|
dontdisconnect enable -dontdisconnect mode.
|
|
|
nodontdisconnect disable -dontdisconnect mode.
|
|
|
(may interfere with other options)
|
|
|
noremote disable the -remote command processing,
|
|
|
it cannot be turned back on.
|
|
|
|
|
|
The vncconnect(1) command from standard VNC
|
|
|
distributions may also be used if string is prefixed
|
|
|
with "cmd=" E.g. 'vncconnect cmd=stop'. Under some
|
|
|
circumstances xprop(1) can used if it supports -set
|
|
|
(see the FAQ).
|
|
|
|
|
|
If "-connect /path/to/file" has been supplied to the
|
|
|
running x11vnc server then that file can be used as a
|
|
|
communication channel (this is the only way to remote
|
|
|
control one of many x11vnc's polling the same X display)
|
|
|
Simply run: 'x11vnc -connect /path/to/file -remote ...'
|
|
|
or you can directly write to the file via something
|
|
|
like: "echo cmd=stop > /path/to/file", etc.
|
|
|
|
|
|
-query variable 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 VNC_CONNECT property or connect
|
|
|
file use "qry=..." instead of "cmd=..."
|
|
|
|
|
|
Here is the current list of "variables" that can
|
|
|
be supplied to the -query command. This includes the
|
|
|
"N/A" ones that return no useful info. For variables
|
|
|
names that do not correspond to an x11vnc option or
|
|
|
remote command, we hope the name makes it obvious what
|
|
|
the returned value corresponds to (hint: the ext_*
|
|
|
variables correspond to the presence of X extensions):
|
|
|
|
|
|
ans= stop quit exit shutdown ping blacken zero
|
|
|
refresh reset close disconnect id sid clip waitmapped
|
|
|
nowaitmapped flashcmap noflashcmap truecolor notruecolor
|
|
|
overlay nooverlay overlay_cursor overlay_yescursor
|
|
|
nooverlay_nocursor nooverlay_cursor nooverlay_yescursor
|
|
|
overlay_nocursor visual scale viewonly noviewonly
|
|
|
shared noshared forever noforever once timeout deny
|
|
|
lock nodeny unlock connect allowonce allow localhost
|
|
|
nolocalhost listen accept gone shm noshm flipbyteorder
|
|
|
noflipbyteorder onetile noonetile solid_color solid
|
|
|
nosolid blackout xinerama noxinerama xrandr noxrandr
|
|
|
xrandr_mode padgeom quiet q noquiet modtweak nomodtweak
|
|
|
xkb noxkb skip_keycodes add_keysyms noadd_keysyms
|
|
|
clear_mods noclear_mods clear_keys noclear_keys
|
|
|
remap repeat norepeat fb nofb bell nobell sel
|
|
|
nosel primary noprimary cursorshape nocursorshape
|
|
|
cursorpos nocursorpos cursor show_cursor noshow_cursor
|
|
|
nocursor xfixes noxfixes xdamage noxdamage xd_area
|
|
|
xd_mem alphacut alphafrac alpharemove noalpharemove
|
|
|
alphablend noalphablend xwarp xwarppointer noxwarp
|
|
|
noxwarppointer buttonmap dragging nodragging
|
|
|
pointer_mode pm input_skip input client_input speeds
|
|
|
debug_pointer dp nodebug_pointer nodp debug_keyboard dk
|
|
|
nodebug_keyboard nodk deferupdate defer wait rfbwait
|
|
|
nap nonap sb screen_blank fs gaps grow fuzz snapfb
|
|
|
nosnapfb progressive rfbport http nohttp httpport
|
|
|
httpdir enablehttpproxy noenablehttpproxy alwaysshared
|
|
|
noalwaysshared nevershared noalwaysshared dontdisconnect
|
|
|
nodontdisconnect desktop noremote
|
|
|
|
|
|
aro= display vncdisplay desktopname http_url auth
|
|
|
users rootshift clipshift scale_str scaled_x scaled_y
|
|
|
scale_numer scale_denom scale_fac scaling_noblend
|
|
|
scaling_nomult4 scaling_pad scaling_interpolate inetd
|
|
|
safer unsafe passwdfile using_shm logfile o rc norc
|
|
|
h help V version lastmod bg sigpipe threads clients
|
|
|
client_count pid ext_xtest ext_xkb ext_xshm ext_xinerama
|
|
|
ext_overlay ext_xfixes ext_xdamage ext_xrandr rootwin
|
|
|
num_buttons button_mask mouse_x mouse_y bpp depth
|
|
|
indexed_color dpy_x dpy_y wdpy_x wdpy_y off_x off_y
|
|
|
cdpy_x cdpy_y coff_x coff_y rfbauth passwd
|
|
|
|
|
|
-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. On the other hand -query requests are
|
|
|
always processed synchronously because they have wait
|
|
|
for the result.
|
|
|
|
|
|
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 Do not process any remote control commands or queries.
|
|
|
|
|
|
A note about security wrt remote control commands.
|
|
|
If someone can connect to the X display and change the
|
|
|
property VNC_CONNECT, then they can remotely control
|
|
|
x11vnc. Normally access to the X display is protected.
|
|
|
Note that if they can modify VNC_CONNECT, they could
|
|
|
also run their own x11vnc and have complete control
|
|
|
of the desktop. If the "-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.
|
|
|
|
|
|
To disable the VNC_CONNECT property channel completely
|
|
|
use -novncconnect.
|
|
|
|
|
|
-unsafe If x11vnc is running as root (e.g. inetd or Xsetup for
|
|
|
a display manager) a few remote commands are disabled
|
|
|
(currently: id:pick, accept:<cmd>, and gone:<cmd>)
|
|
|
because they are associated with running external
|
|
|
programs. If you specify -unsafe, then these remote
|
|
|
control commands are allowed when running as root.
|
|
|
When running as non-root all commands are allowed.
|
|
|
See -safer below.
|
|
|
-safer Even if not running as root, disable the above unsafe
|
|
|
remote control commands.
|
|
|
|
|
|
-deny_all For use with -remote nodeny: start out denying all
|
|
|
incoming clients until "-remote nodeny" is used to
|
|
|
let them in.
|
|
|
|
|
|
|
|
|
These options are passed to libvncserver:
|
|
|
|
|
|
-rfbport port TCP port for RFB protocol
|
|
|
-rfbwait time max time in ms to wait for RFB client
|
|
|
-rfbauth passwd-file use authentication on RFB protocol
|
|
|
(use 'storepasswd' to create a password file)
|
|
|
-passwd plain-password use authentication
|
|
|
(use plain-password as password, USE AT YOUR RISK)
|
|
|
-deferupdate time time in ms to defer updates (default 40)
|
|
|
-desktop name VNC desktop name (default "LibVNCServer")
|
|
|
-alwaysshared always treat new clients as shared
|
|
|
-nevershared never treat new clients as shared
|
|
|
-dontdisconnect don't disconnect existing clients when a new non-shared
|
|
|
connection comes in (refuse new connection instead)
|
|
|
-httpdir dir-path enable http server using dir-path home
|
|
|
-httpport portnum use portnum for http connection
|
|
|
-enablehttpproxy enable http proxy support
|
|
|
-progressive height enable progressive updating for slow links
|
|
|
-listen ipaddr listen for connections only on network interface with
|
|
|
addr ipaddr. '-listen localhost' and hostname work too.
|
|
|
|
|
|
Pretty wild huh? [1]Contact me if you have any questions or problems.
|
|
|
|
|
|
Personally, I use:
|
|
|
x11vnc -rfbauth $HOME/.vnc/passwd -nap -flashcmap -cursor X -add_keysyms
|
|
|
|
|
|
(the -flashcmap only matters on old 8-bit X displays)
|
|
|
|
|
|
References
|
|
|
|
|
|
1. mailto:xvml@karlrunge.com
|
