x11vnc: FINDCREATEDISPLAY support to create X session if one cannot be found. Fix bug in java viewer.

1 files changed, 85 insertions, 36 deletions

diff --git a/x11vnc/help.c b/x11vnc/help.c
index cd9d6e6..4096e1c 100644
--- a/x11vnc/help.c
+++ b/x11vnc/help.c
@@ -685,17 +685,27 @@ void print_help(int mode) {
 "\n"
 "                       If the string is, e.g. WAIT:0.0 or WAIT:1, i.e. \"WAIT\"\n"
 "                       in front of a normal X display, then that indicated\n"
-"                       display is used.  A more interesting case is like this:\n"
+"                       display is used.\n"
+"\n"
+"                       One can also insert a geometry between colons, e.g.\n"
+"                       WAIT:1280x1024:... to set the size of the display the\n"
+"                       VNC client first attaches to since some VNC viewers\n"
+"                       will not automatically adjust to a new framebuffer size.\n"
+"\n"
+"                       A more interesting case is like this:\n"
 "\n"
 "                            WAIT:cmd=/usr/local/bin/find_display\n"
 "\n"
 "                       in which case the command after \"cmd=\" is run to\n"
 "                       dynamically work out the DISPLAY and optionally the\n"
 "                       XAUTHORITY data.  The first line of the command output\n"
-"                       must be of the form DISPLAY=<xdisplay>.  Any remaining\n"
-"                       output is taken as XAUTHORITY data.  It can be either\n"
-"                       of the form XAUTHORITY=<file> or raw xauthority data for\n"
-"                       the display (e.g. \"xauth extract - $DISPLAY\" output).\n"
+"                       must be of the form DISPLAY=<xdisplay>.  On Linux\n"
+"                       if the virtual terminal is known append \",VT=n\" to\n"
+"                       this string and the chvt(1) program will also be run.\n"
+"                       Any remaining output is taken as XAUTHORITY data.\n"
+"                       It can be either of the form XAUTHORITY=<file> or raw\n"
+"                       xauthority data for the display (e.g. \"xauth extract -\n"
+"                       $DISPLAY\" output).\n"
 "\n"
 #ifndef NO_SSL_OR_UNIXPW
 "                       In the case of -unixpw (but not -unixpw_nis), then the\n"
@@ -749,6 +759,7 @@ void print_help(int mode) {
 "                       As a special case, WAIT:cmd=FINDDISPLAY will run a\n"
 "                       script that works on most Unixes to determine a user's\n"
 "                       DISPLAY variable and xauthority data (see who(1)).\n"
+"\n"
 "                       To have this default script printed to stdout (e.g. for\n"
 "                       customization) run with WAIT:cmd=FINDDISPLAY-print\n"
 "\n"
@@ -765,10 +776,46 @@ void print_help(int mode) {
 "                       Where /.../x11vnc is the full path to x11vnc.\n"
 "                       It is used in the Apache SSL-portal example (see FAQ).\n"
 "\n"
-"                       Finally, one can insert a geometry between colons,\n"
-"                       e.g. WAIT:1280x1024:... to set the size of the display\n"
-"                       the VNC client first attaches to since some VNC viewers\n"
-"                       will not automatically adjust to a new framebuffer size.\n"
+"                       An experimental option is WAIT:cmd=FINDCREATEDISPLAY\n"
+"                       that is like FINDDISPLAY in that is uses the same method\n"
+"                       to find an existing display.  However, if it does not\n"
+"                       find one it will try to *start* up an X server session\n"
+"                       for the user.  This is the only time x11vnc tries to\n"
+"                       start up an X server.\n"
+"\n"
+"                       By default FINDCREATEDISPLAY will try Xdummy and\n"
+"                       then Xvfb.  The Xdummy wrapper is part of the x11vnc\n"
+"                       source code (x11vnc/misc/Xdummy)  It should be available\n"
+"                       in PATH and have run \"Xdummy -install\" once to create\n"
+"                       the shared library.  Xdummy requires root permission\n"
+"                       and only works on Linux.  Xvfb is available on most\n"
+"                       platforms.\n"
+"\n"
+"                       When x11vnc exits (i.e. user disconnects) the X server\n"
+"                       session stays running in the background.  Presumably the\n"
+"                       FINDDISPLAY will find it next time.  The user must exit\n"
+"                       the X session in the usual way for it to terminate.\n"
+"\n"
+"                       So this is a somewhat odd mode for x11vnc in that it\n"
+"                       will start up and poll virtual X servers.  This can\n"
+"                       be used from, say, inetd(8) to provide a means of\n"
+"                       definitely getting a desktop (either real or virtual)\n"
+"                       on the machine.  E.g. a desktop service:\n"
+"\n"
+"                         5915 stream tcp nowait root /usr/sbin/tcpd /.../x11vnc\n"
+"                          -inetd -q -http -ssl SAVE -unixpw -users unixpw=\\\n"
+"                          -passwd secret -prog /.../x11vnc \\\n"
+"                          -display WAIT:cmd=FINDCREATEDISPLAY\n"
+"\n"
+"                       Where /.../x11vnc is the full path to x11vnc.\n"
+"\n"
+"                       Use WAIT:cmd=FINDCREATEDISPLAY-print to print out the\n"
+"                       script used.  You can specify the preferred order via\n"
+"                       e.g., WAIT:cmd=FINDCREATEDISPLAY-Xdummy,Xvfb,X  and/or\n"
+"                       leave out ones you do not want.  The the extra case \"X\"\n"
+"                       means try to start up a real, hardware X server using\n"
+"                       xinit(1).  If there is already an X server running the\n"
+"                       X case may only work on Linux (see startx(1)).\n"
 "\n"
 #ifndef NO_SSL_OR_UNIXPW
 "-ssl [pem]             Use the openssl library (www.openssl.org) to provide a\n"
@@ -2524,35 +2571,37 @@ void print_help(int mode) {
 "                       Default: %d\n"
 "-debug_tiles           Print debugging output for tiles, fb updates, etc.\n"
 "\n"
-"-snapfb                Instead of polling the X display framebuffer (fb) for\n"
-"                       changes, periodically copy all of X display fb into main\n"
-"                       memory and examine that copy for changes.  Under some\n"
-"                       circumstances this will improve interactive response,\n"
-"                       or at least make things look smoother, but in others\n"
-"                       (most!) it will make the response worse.  If the video\n"
-"                       h/w fb is such that reading small tiles is very slow\n"
-"                       this mode could help.  To keep the \"framerate\" up\n"
-"                       the screen size x bpp cannot be too large.  Note that\n"
+"-snapfb                Instead of polling the X display framebuffer (fb)\n"
+"                       for changes, periodically copy all of X display fb\n"
+"                       into main memory and examine that copy for changes.\n"
+"                       (This setting also applies for non-X -rawfb modes).\n"
+"                       Under some circumstances this will improve interactive\n"
+"                       response, or at least make things look smoother, but in\n"
+"                       others (most!) it will make the response worse.  If the\n"
+"                       video h/w fb is such that reading small tiles is very\n"
+"                       slow this mode could help.  To keep the \"framerate\"\n"
+"                       up the screen size x bpp cannot be too large.  Note that\n"
 "                       this mode is very wasteful of memory I/O resources\n"
 "                       (it makes full screen copies even if nothing changes).\n"
 "                       It may be of use in video capture-like applications,\n"
-"                       or where window tearing is a problem.\n"
+"                       webcams, or where window tearing is a problem.\n"
 "\n"
 "-rawfb string          Instead of polling X, poll the memory object specified\n"
 "                       in \"string\".\n"
 "\n"
-"                       For shared memory segments string is of the\n"
-"                       form: \"shm:N@WxHxB\" which specifies a shmid\n"
-"                       N and framebuffer Width, Height, and Bits\n"
-"                       per pixel.\n"
-"\n"
 "                       For file polling to memory map mmap(2) a file use:\n"
-"                       \"map:/path/to/a/file@WxHxB\", with WxHxB as above.\n"
-"                       \"mmap:...\" is the same. If there is trouble with mmap,\n"
-"                       use  \"file:/...\" for slower lseek(2) based reading.\n"
-"                       Use \"snap:...\" to imply -snapfb mode and the \"file:\"\n"
-"                       access (this is for devices that only provide the fb\n"
-"                       all at once).\n"
+"                       \"map:/path/to/a/file@WxHxB\", with framebuffer Width,\n"
+"                       Height, and Bits per pixel.  \"mmap:...\" is the\n"
+"                       same.\n"
+"\n"
+"                       If there is trouble with mmap, use  \"file:/...\"\n"
+"                       for slower lseek(2) based reading.  Use \"snap:...\"\n"
+"                       to imply -snapfb mode and the \"file:\" access (this\n"
+"                       is for devices that only provide the fb all at once).\n"
+"\n"
+"                       For shared memory segments string is of the form:\n"
+"                       \"shm:N@WxHxB\" which specifies a shmid N and with\n"
+"                       WxHxB as above.  See shmat(1) and ipcs(1)\n"
 "\n"
 "                       If you do not supply a type \"map\" is assumed if\n"
 "                       the file exists (see the next paragraphs for some\n"
@@ -2579,7 +2628,7 @@ void print_help(int mode) {
 "                       guesses them based on the bpp.\n"
 "\n"
 "                       Another optional suffix is the Bytes Per Line which in\n"
-"                       some cases is not WxHxB/4.  Specify it as WxHxB-BPL\n"
+"                       some cases is not WxB/4.  Specify it as WxHxB-BPL\n"
 "                       e.g. 800x600x16-2048.  This could be a normal width\n"
 "                       1024 at 16bpp fb, but only width 800 shows up.\n"
 "\n"
@@ -2612,11 +2661,11 @@ void print_help(int mode) {
 "                       display, this usage should be very rare, i.e. doing\n"
 "                       something strange with /dev/fb0.\n"
 "\n"
-"                       If the device is not \"seekable\" try reading it all\n"
-"                       at once in full snaps via the \"snap:\" mode (note:\n"
-"                       this is a resource hog).  If you are using file: or\n"
-"                       map: and the device needs to be reopened for *every*\n"
-"                       snapfb snapshot, set the environment variable:\n"
+"                       If the device is not \"seekable\" (e.g. webcam) try\n"
+"                       reading it all at once in full snaps via the \"snap:\"\n"
+"                       mode (note: this is a resource hog).  If you are using\n"
+"                       file: or map: and the device needs to be reopened for\n"
+"                       *every* snapfb snapshot, set the environment variable:\n"
 "                       SNAPFB_RAWFB_RESET=1 as well.\n"
 "\n"
 "                       If you want x11vnc to dynamically transform a 24bpp\n"