Less safe, but to avoid figuring out where the correct XAUTHORITY file is, if the person sitting at the physical 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 soon be of use (please read the documentation on the -users option.
This usually requires about 50-100MB of additional RAM on both the client and server sides. Another drawback of the scheme is that it is VERY memory intensive, the n in “-ncache n” is the factor of increase over the base framebuffer size to use for caching. It is an even integer and should be fairly large, 6-12, to achieve good response. If you are running on low memory machines or memory is tight because of other running applications you should not use -ncache. For example with n=6 a 1280×1024 display will use a framebuffer that is 1280×7168: everything below row 1024 is the pixel buffer cache.
Finally, the framebuffer may not begin at the beginning of the memory object, so use the optional “+offset” parameter to indicate where the framebuffer information starts. BTW, since XWD is not strictly RGB the view will only be approximate, but usable. The format of these is XWD and so the initial header should be skipped. Of course for the case of Xvfb x11vnc can poll it much better via the X API, but you get the idea. So as an example, the Xvfb virtual framebuffer has options -shmem and -fbdir for exporting its virtual screen to either shm or a mapped file.
The older ANONTLS method (vino) is also supported. Update: As of Nov/2008 x11vnc also supports the VeNCrypt SSL/TLS tunnel extension to the VNC protocol. This support is on by default when the -ssl option is in use and can be fine-tuned using these options: -vencrypt, -anontls, and -sslonly.
See the previous FAQ’s for non-X11 framebuffer usage. If you use this for an interesting non-X11 application please let us know what you did. Yes, as of Jul/2006 x11vnc enables building for -rawfb only support. /configure –without-x (plus any other flags) make You can then test via “ldd x11vnc” that the binary does not depend on libX11. Just do something like when building:.
In general -unixpw is not required for this sort of scheme, but it is convenient because it determines exactly who the Unix user is whose display should be sought. Note that SSL is required for this mode because otherwise the Unix password would be passed in clear text over the network. Otherwise the find_display script would have to use some method to work out DISPLAY, XAUTHORITY, etc (perhaps you use multiple inetd ports and hardwire usernames for different ports.
Try it if the other options don’t help. This is the simplest form of keystroke insertion and it actually solved the problem. Note that one user had a strange setup and none of the above helped. His solution was to disable all of the above and use -nomodtweak.
The -8to24 method does this approximately and is somewhat usable. Fortunately the -overlay option works for Solaris machines with overlay visuals where most of this problem occurs. 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.
Consider reconfiguring the system to 16 bpp or depth 24 TrueColor if at all possible. Use the -flashcmap option to have x11vnc watch for changes in the colormap, and propagate those changes back to connected clients. “netscape -install” is a well-known historical example of this. 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.
Use the “-connect_or_exit” option to have x11vnc exit if the reverse connection fails. Also, note the “-rfbport 0” option disables TCP listening for connections (potentially useful for reverse connection mode, assuming you do not want any “forward” connections.
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. 23 30/04/2004 14:04:26 other clients: X Error of failed request: BadAccess (attempt to access private resource denied) 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. Things are even more tight on Solaris 8 and earlier, there is a default maximum number of shm segments per process of 6.
I have made upgrade from F22 to F23, later from F23 to F25 (directly),
and just last week from F25 to F27, and was done quite without any problem. So You are sure to get the last Fedora key , used to sign the package provided with the last new realease.