.\" This file was automatically generated from x11vnc -help output. .TH X11VNC "1" "August 2004" "x11vnc " "User Commands" .SH NAME x11vnc - allow VNC connections to real X11 displays version: 0.6.3pre, lastmod: 2004-08-31 .SH SYNOPSIS .B x11vnc [OPTION]... .SH DESCRIPTION .PP Typical usage is: .IP Run this command in a shell on the remote machine "far-host" with X session you wish to view: .IP x11vnc -display :0 .IP Then run this in another window on the machine you are sitting at: .IP vncviewer far-host:0 .PP Once x11vnc establishes connections with the X11 server and starts listening as a VNC server it will print out a string: PORT=XXXX where XXXX is typically 5900 (the default VNC port). One would next run something like this on the local machine: "vncviewer host:N" where N is XXXX - 5900, i.e. usually "vncviewer host:0" .PP By default x11vnc will not allow the screen to be shared and it will exit as soon as a client disconnects. See \fB-shared\fR and \fB-forever\fR below to override these protections. .PP For additional info see: http://www.karlrunge.com/x11vnc/ and http://www.karlrunge.com/x11vnc/#faq .PP Rudimentary config file support: if the file $HOME/.x11vncrc exists then each line in it is treated as a single command line option. Disable with \fB-norc.\fR For each option name, the leading character "-" is not required. E.g. a line that is either "nap" or "-nap" 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). .PP .SH OPTIONS .PP \fB-display\fR \fIdisp\fR .IP X11 server display to connect to, usually :0. The X server process must be running on same machine and support MIT-SHM. Equivalent to setting the DISPLAY environment variable to \fIdisp\fR. .PP \fB-auth\fR \fIfile\fR .IP Set the X authority file to be \fIfile\fR, equivalent to setting the XAUTHORITY environment varirable to \fIfile\fR before startup. See .IR Xsecurity (7) , .IR xauth (1) man pages. .PP \fB-id\fR \fIwindowid\fR .IP Show the window corresponding to \fIwindowid\fR not the entire display. New windows like popup menus, etc may not be seen, or will be clipped. x11vnc may crash if the window changes size, is iconified, etc. Use .IR xwininfo (1) to get the window id. Primarily useful for exporting very simple applications. .PP \fB-sid\fR \fIwindowid\fR .IP As \fB-id,\fR but instead of using the window directly it shifts a root view to it: this shows saveUnders menus, etc, although they will be clipped if they extend beyond the window. .PP \fB-flashcmap\fR .IP In 8bpp indexed color, let the installed colormap flash as the pointer moves from window to window (slow). .PP \fB-notruecolor\fR .IP For 8bpp displays, force indexed color (i.e. a colormap) even if it looks like 8bpp TrueColor. (rare problem) .PP \fB-overlay\fR .IP Handle multiple depth visuals on one screen, e.g. 8+24 and 24+8 overlay visuals (the 32 bits per pixel are packed with 8 for PseudoColor and 24 for TrueColor). .IP Currently \fB-overlay\fR only works on Solaris (it uses XReadScreen(3X11)). 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, say). Also note that, the mouse cursor shape is exactly correct in this mode. .IP Use \fB-overlay\fR as a workaround for situations like these: Some legacy applications require the default visual be 8bpp (8+24), or they will use 8bpp PseudoColor even when the default visual is depth 24 TrueColor (24+8). In these cases colors in some windows will be messed up in x11vnc unless \fB-overlay\fR is used. .IP Under \fB-overlay,\fR performance will be somewhat degraded due to the extra image transformations required. For optimal performance do not use \fB-overlay,\fR but rather configure the X server so that the default visual is depth 24 TrueColor and try to have all apps use that visual (some apps have \fB-use24\fR or \fB-visual\fR options). .PP \fB-overlay_nocursor\fR .IP Sets \fB-overlay,\fR but does not try to draw the exact mouse cursor shape using the overlay mechanism. .PP \fB-visual\fR \fIn\fR .IP Experimental option: probably does not do what you think. It simply *forces* the visual used for the framebuffer; this may be a bad thing... It is useful for testing and for some workarounds. n may be a decimal number, or 0x hex. Run .IR xdpyinfo (1) for the values. One may also use "TrueColor", etc. see for a list. If the string ends in ":m" for better or for worse the visual depth is forced to be m. .PP \fB-scale\fR \fIfraction\fR .IP Scale the framebuffer by factor \fIfraction\fR. Values less than 1 shrink the fb. Note: image may not be sharp and response may be slower. Currently the cursor shape is not scaled. If \fIfraction\fR contains a decimal point "." it is taken as a floating point number, alternatively the notation "m/n" may be used to denote fractions exactly, e.g. \fB-scale\fR 2/3. .IP Scaling Options: can be added after \fIfraction\fR via ":", to supply multiple ":" options use commas. If you just want a quick, rough scaling without blending, append ":nb" to \fIfraction\fR (e.g. \fB-scale\fR 1/3:nb). For compatibility with vncviewers the scaled width is adjusted to be a multiple of 4: to disable this use ":n4". More esoteric options: ":in" use interpolation scheme even when shrinking, ":pad", pad scaled width and height to be multiples of scaling denominator (e.g. 3 for 2/3). .PP \fB-viewonly\fR .IP All VNC clients can only watch (default off). .PP \fB-shared\fR .IP VNC display is shared (default off). .PP \fB-once\fR .IP Exit after the first successfully connected viewer disconnects, opposite of \fB-forever.\fR This is the Default. .PP \fB-forever\fR .IP Keep listening for more connections rather than exiting as soon as the first client(s) disconnect. Same as \fB-many\fR .PP \fB-connect\fR \fIstring\fR .IP For use with "vncviewer -listen" reverse connections. If \fIstring\fR has the form "host" or "host:port" the connection is made once at startup. Use commas for a list of host's and host:port's. If \fIstring\fR contains "/" it is instead interpreted as a file to periodically check for new hosts. The first line is read and then the file is truncated. .PP \fB-vncconnect\fR .IP Monitor the VNC_CONNECT X property set by the standard .PP \fB-novncconnect\fR .IP VNC program .IR vncconnect (1) . When the property is set to "host" or "host:port" establish a reverse connection. Using .IR xprop (1) instead of vncconnect may work, see the FAQ. Default: \fB-vncconnect\fR .PP \fB-inetd\fR .IP Launched by .IR inetd (1) : stdio instead of listening socket. Note: if you are not redirecting stderr to a log file (via shell 2> or \fB-o\fR option) you must also specify the \fB-q\fR option. .PP \fB-allow\fR \fIaddr1[,addr2..]\fR .IP Only allow client connections from IP addresses matching the comma separated list of numerical addresses. Can be a prefix, e.g. "192.168.100." to match a simple subnet, for more control build libvncserver with libwrap support. If the list contains a "/" it instead is a interpreted as a file containing addresses or prefixes that is re-read each time a new client connects. Lines can be commented out with the "#" character in the usual way. .PP \fB-localhost\fR .IP Same as \fB-allow\fR 127.0.0.1 .PP \fB-viewpasswd\fR \fIstring\fR .IP Supply a 2nd password for view-only logins. The \fB-passwd\fR (full-access) password must also be supplied. .PP \fB-passwdfile\fR \fIfilename\fR .IP Specify libvncserver \fB-passwd\fR via the first line of the file \fIfilename\fR instead of via command line. If a second non blank line exists in the file it is taken as a view-only password (i.e. \fB-viewpasswd)\fR Note: this is a simple plaintext passwd, see also \fB-rfbauth\fR and \fB-storepasswd\fR below. .PP \fB-storepasswd\fR \fIpass\fR \fIfile\fR .IP Store password \fIpass\fR as the VNC password in the file \fIfile\fR. Once the password is stored the program exits. Use the password via "-rfbauth file" .PP \fB-accept\fR \fIstring\fR .IP Run a command (possibly to prompt the user at the X11 display) to decide whether an incoming client should be allowed to connect or not. \fIstring\fR is an external command run via .IR system (3) or some special cases described below. Be sure to quote \fIstring\fR if it contains spaces, etc. If the external command returns 0 the client is accepted, otherwise the client is rejected. See below for an extension to accept a client view-only. .IP Environment: The RFB_CLIENT_IP environment variable will be set to the incoming client IP number and the port in RFB_CLIENT_PORT (or -1 if unavailable). Similarly, RFB_SERVER_IP and RFB_SERVER_PORT (the x11vnc side of the connection), are set to allow identification of the tcp virtual circuit. The x11vnc process id will be in RFB_X11VNC_PID, a client id number in RFB_CLIENT_ID, and the number of other connected clients in RFB_CLIENT_COUNT. .IP If \fIstring\fR is "popup" then a builtin popup window is used. The popup will time out after 120 seconds, use "popup:N" to modify the timeout to N seconds (use 0 for no timeout) .IP If \fIstring\fR is "xmessage" then an .IR xmessage (1) invocation is used for the command. .IP Both "popup" and "xmessage" will present an option for accepting the client "View-Only" (the client can only watch). This option will not be presented if \fB-viewonly\fR has been specified, in which case the entire display is view only. .IP If the user supplied command is prefixed with something like "yes:0,no:*,view:3 mycommand ..." then this associates the numerical command return code with the actions: accept, reject, and accept-view-only, respectively. Use "*" instead of a number to indicate the default action (in case the command returns an unexpected value). E.g. "no:*" is a good choice. .IP Note that x11vnc blocks while the external command or or popup is running (other clients may see no updates during this period). .IP More \fB-accept\fR tricks: use "popupmouse" to only allow mouse clicks in the builtin popup to be recognized. Similarly use "popupkey" to only recognize keystroke responses. All 3 of the popup keywords can be followed by +N+M to supply a position for the popup window. The default is to center the popup window. .PP \fB-gone\fR \fIstring\fR .IP As \fB-accept,\fR except to run a user supplied command when a client goes away (disconnects). Unlike \fB-accept,\fR the command return code is not interpreted by x11vnc. .PP \fB-noshm\fR .IP Do not use the MIT-SHM extension for the polling. Remote displays can be polled this way: be careful this can use large amounts of network bandwidth. This is also of use if the local machine has a limited number of shm segments and \fB-onetile\fR is not sufficient. .PP \fB-flipbyteorder\fR .IP Sometimes needed if remotely polled host has different endianness. Ignored unless \fB-noshm\fR is set. .PP \fB-onetile\fR .IP Do not use the new copy_tiles() framebuffer mechanism, just use 1 shm tile for polling. Limits shm segments used to 3. .PP \fB-blackout\fR \fIstring\fR .IP Black out rectangles on the screen. \fIstring\fR is a comma separated list of WxH+X+Y type geometries for each rectangle. .PP \fB-xinerama\fR .IP If your screen is composed of multiple monitors glued together via XINERAMA, and that screen is non-rectangular this option will try to guess the areas to black out (if your system has libXinerama). In general on XINERAMA displays you may need to use the \fB-xwarppointer\fR option if the mouse pointer misbehaves. .PP \fB-o\fR \fIlogfile\fR .IP Write stderr messages to file \fIlogfile\fR instead of to the terminal. Same as \fB-logfile\fR "file". .PP \fB-rc\fR \fIfilename\fR .IP Use \fIfilename\fR instead of $HOME/.x11vncrc for rc file. .PP \fB-norc\fR .IP Do not process any .x11vncrc file for options. .PP \fB-h,\fR \fB-help\fR .IP Print this help text. .PP \fB-V,\fR \fB-version\fR .IP Print program version (last modification date). .PP \fB-q\fR .IP Be quiet by printing less informational output to stderr. Same as \fB-quiet.\fR .PP \fB-bg\fR .IP Go into the background after screen setup. Messages to stderr are lost unless \fB-o\fR logfile is used. Something like this could be useful in a script: .IP port=`ssh $host "x11vnc -display :0 -bg" | grep PORT` .IP port=`echo "$port" | sed -e 's/PORT=//'` .IP port=`expr $port - 5900` .IP vncviewer $host:$port .PP \fB-modtweak,\fR \fB-nomodtweak\fR .IP Option \fB-modtweak\fR automatically tries to adjust the AltGr and Shift modifiers for differing language keyboards between client and host. Otherwise, only a single key press/release of a Keycode is simulated (i.e. ignoring the state of the modifiers: this usually works for identical keyboards). Also useful in resolving cases where a Keysym is bound to multiple keys (e.g. "<" + ">" and "," + "<" keys). Default: \fB-modtweak\fR .PP \fB-xkb\fR .IP When in modtweak mode, use the XKEYBOARD extension (if it exists) to do the modifier tweaking. This is powerful and should be tried if there are still keymapping problems when using the simpler \fB-modtweak.\fR .PP \fB-skip_keycodes\fR \fIstring\fR .IP Skip keycodes not on your keyboard but your X server thinks exist. Currently only applies to \fB-xkb\fR mode. \fIstring\fR is a comma separated list of decimal keycodes. Use this option to help x11vnc in the reverse problem it tries to solve: Keysym -> Keycode(s) when ambiguities exist. E.g. \fB-skip_keycodes\fR 94,114 .PP \fB-add_keysyms\fR .IP If a Keysym is received from a VNC viewer and that Keysym does not exist in the X server, then add the Keysym to the X server's keyboard mapping. Added Keysyms will be removed when exiting. .PP \fB-clear_mods\fR .IP At startup and exit clear the modifier keys by sending KeyRelease for each one. The Lock modifiers are skipped. Used to clear the state if the display was accidentally left with any pressed down. .PP \fB-clear_keys\fR .IP As \fB-clear_mods,\fR except try to release any pressed key. Note that this option and \fB-clear_mods\fR can interfere with a person typing at the physical keyboard. .PP \fB-remap\fR \fIstring\fR .IP Read Keysym remappings from file named \fIstring\fR. Format is one pair of Keysyms per line (can be name or hex value) separated by a space. If no file named \fIstring\fR exists, it is instead interpreted as this form: key1-key2,key3-key4,... See header file for a list of Keysym names, or use .IR xev (1) . To map a key to a button click, use the fake Keysyms "Button1", ..., etc. E.g. \fB-remap\fR Super_R-Button2 .PP \fB-norepeat,\fR \fB-repeat\fR .IP Option \fB-norepeat\fR disables X server key auto repeat when VNC clients are connected. This works around a repeating keystrokes bug (triggered by long processing delays between key down and key up client events: either from large screen changes or high latency). Note: your VNC viewer side will likely do autorepeating, so this is no loss unless someone is simultaneously at the real X display. Default: \fB-repeat\fR .PP \fB-nofb\fR .IP Ignore video framebuffer: only process keyboard and pointer. Intended for use with Win2VNC and x2vnc dual-monitor setups. .PP \fB-nobell\fR .IP Do not watch for XBell events. (no beeps will be heard) Note: XBell monitoring requires the XKEYBOARD extension. .PP \fB-nosel\fR .IP Do not manage exchange of X selection/cutbuffer between VNC viewers and the X server. .PP \fB-noprimary\fR .IP Do not poll the PRIMARY selection for changes to send back to clients. (PRIMARY is still set on received changes, however). .PP \fB-cursor\fR \fI[mode],\fR \fB-nocursor\fR .IP Sets how the pointer cursor shape (little icon at the mouse pointer) should be handled. The "mode" string is optional and is described below. The default is to show some sort of cursor shape(s). How this is done depends on the VNC viewer and the X server. Use \fB-nocursor\fR to disable cursor shapes completely. .IP Some VNC viewers support the TightVNC CursorPosUpdates and CursorShapeUpdates extensions (cuts down on network traffic by not having to send the cursor image every time the pointer is moved), in which case these extensions are used (see \fB-nocursorshape\fR and \fB-nocursorpos\fR below). For other viewers the cursor shape is written directly to the framebuffer every time the pointer is moved or changed and gets sent along with the other framebuffer updates. In this case, there will be some lag between the vnc viewer pointer and the remote cursor position. .IP If the X display supports retrieving the cursor shape information from the X server, then the default is to use that mode. On Solaris this requires the SUN_OVL extension and the \fB-overlay\fR option to be supplied. (see also the \fB-overlay_nomouse\fR option). (Soon) on XFree86/Xorg the XFIXES extension is required. Either can be disabled with \fB-nocursor,\fR and also some values of the "mode" option below. .IP The "mode" string can be used to fine-tune the displaying of cursor shapes. It can be used the following ways: .IP "-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. .IP "-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. .IP "-cursor most" - try to show as many cursors as possible. Often this will only be the same as "some". On Solaris if XFIXES is not available, \fB-overlay\fR mode will be used. .PP \fB-nocursorshape\fR .IP Do not use the TightVNC CursorShapeUpdates extension even if clients support it. See \fB-cursor\fR above. .PP \fB-cursorpos,\fR \fB-nocursorpos\fR .IP Option \fB-cursorpos\fR enables sending the X cursor position back to all vnc clients that support the TightVNC CursorPosUpdates extension. Other clients will be able to see the pointer motions. Default: \fB-cursorpos\fR .PP \fB-xwarppointer\fR .IP Move the pointer with XWarpPointer(3X) instead of XTEST extension. Use this as a workaround if the pointer motion behaves incorrectly, e.g. on touchscreens or other non-standard setups. Also sometimes needed on XINERAMA displays. .PP \fB-buttonmap\fR \fIstring\fR .IP String to remap mouse buttons. Format: IJK-LMN, this maps buttons I -> L, etc., e.g. \fB-buttonmap\fR 13-31 .IP Button presses can also be mapped to keystrokes: replace a button digit on the right of the dash with :: or :+: etc. for multiple keys. For example, if the viewing machine has a mouse-wheel (buttons 4 5) but the x11vnc side does not, these will do scrolls: .IP \fB-buttonmap\fR 12345-123:Prior::Next: .IP \fB-buttonmap\fR 12345-123:Up+Up+Up::Down+Down+Down: .IP See header file for a list of Keysyms, or use the .IR xev (1) program. Note: mapping of button clicks to Keysyms may not work if \fB-modtweak\fR or \fB-xkb\fR is needed for the Keysym. .IP If you include a modifier like "Shift_L" the modifier's up/down state is toggled, e.g. to send "The" use :Shift_L+t+Shift_L+h+e: (the 1st one is shift down and the 2nd one is shift up). (note: the initial state of the modifier is ignored and not reset) To include button events use "Button1", ... etc. .PP \fB-nodragging\fR .IP Do not update the display during mouse dragging events (mouse motion with a button held down). Greatly improves response on slow setups, but you lose all visual feedback for drags, text selection, and some menu traversals. .PP \fB-old_pointer\fR .IP Use the original pointer input handling mechanism. See check_input() and pointer() in source file for details. .PP \fB-old_pointer2\fR .IP The default pointer input handling algorithm was changed again, this option indicates to use the second one. .PP \fB-input_skip\fR \fIn\fR .IP For the old 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. .PP \fB-debug_pointer\fR .IP Print debugging output for every pointer event. .PP \fB-debug_keyboard\fR .IP Print debugging output for every keyboard event. .PP Same as \fB-dp\fR and \fB-dk,\fR respectively. Use multiple times for more output. .PP \fB-defer\fR \fItime\fR .IP Time in ms to wait for updates before sending to client (deferUpdateTime) Default: 30 .PP \fB-wait\fR \fItime\fR .IP Time in ms to pause between screen polls. Used to cut down on load. Default: 30 .PP \fB-nap\fR .IP Monitor activity and if low take longer naps between polls to really cut down load when idle. Default: off .PP \fB-sigpipe\fR \fIstring\fR .IP Broken pipe (SIGPIPE) handling. \fIstring\fR can be "ignore" or "exit". For "ignore" libvncserver will handle the abrupt loss of a client and continue, for "exit" x11vnc will cleanup and exit at the 1st broken connection. Default: "ignore". .PP \fB-threads,\fR \fB-nothreads\fR .IP Whether or not to use the threaded libvncserver algorithm [rfbRunEventLoop] if libpthread is available Default: \fB-nothreads\fR .PP \fB-fs\fR \fIf\fR .IP If the fraction of changed tiles in a poll is greater than f, the whole screen is updated. Default: 0.75 .PP \fB-gaps\fR \fIn\fR .IP Heuristic to fill in gaps in rows or cols of n or less tiles. Used to improve text paging. Default: 4 .PP \fB-grow\fR \fIn\fR .IP Heuristic to grow islands of changed tiles n or wider by checking the tile near the boundary. Default: 3 .PP \fB-fuzz\fR \fIn\fR .IP Tolerance in pixels to mark a tiles edges as changed. Default: 2 .PP These options are passed to libvncserver: .PP \fB-rfbport\fR \fIport\fR .IP TCP port for RFB protocol .PP \fB-rfbwait\fR \fItime\fR .IP max time in ms to wait for RFB client .PP \fB-rfbauth\fR \fIpasswd-file\fR .IP use authentication on RFB protocol (use 'storepasswd' to create a password file) .PP \fB-passwd\fR \fIplain-password\fR .IP use authentication (use plain-password as password, USE AT YOUR RISK) .PP \fB-deferupdate\fR \fItime\fR .IP time in ms to defer updates (default 40) .PP \fB-desktop\fR \fIname\fR .IP VNC desktop name (default "LibVNCServer") .PP \fB-alwaysshared\fR .IP always treat new clients as shared .PP \fB-nevershared\fR .IP never treat new clients as shared .PP \fB-dontdisconnect\fR .IP don't disconnect existing clients when a new non-shared connection comes in (refuse new connection instead) .PP \fB-httpdir\fR \fIdir-path\fR .IP enable http server using dir-path home .PP \fB-httpport\fR \fIportnum\fR .IP use portnum for http connection .PP \fB-enablehttpproxy\fR .IP enable http proxy support .PP \fB-progressive\fR \fIheight\fR .IP enable progressive updating for slow links .SH "FILES" .IR $HOME/.x11vncrc , .IR $HOME/.Xauthority .SH "ENVIRONMENT" .IR DISPLAY , .IR XAUTHORITY , .IR HOME .PP The following are set for the auxiliary commands run by \fB-accept\fR and \fB-gone\fR: .PP .IR RFB_CLIENT_IP , .IR RFB_CLIENT_PORT , .IR RFB_SERVER_IP , .IR RFB_SERVER_PORT , .IR RFB_X11VNC_PID , .IR RFB_CLIENT_ID , .IR RFB_CLIENT_COUNT .SH "SEE ALSO" .IR vncviewer (1), .IR vncpasswd (1), .IR vncconnect (1), .IR vncserver (1), .IR Xvnc (1), .IR inetd (1), .IR xev (1), .IR xmodmap (1), .IR Xserver (1), .IR xauth (1), .IR xhost (1), .IR Xsecurity (7), .IR xmessage (1), .IR ipcrm (1), .IR http://www.tightvnc.com , .IR http://www.realvnc.com , .IR http://www.karlrunge.com/x11vnc/ .SH AUTHORS x11vnc was written by Karl J. Runge , it is part of the LibVNCServer project . This manual page is based one the one written by Ludovic Drolez , for the Debian project (both may be used by others).