xllvnc 启动失败 XOpenDisplay("") failed.

26/07/2017 08:12:24 passing arg to libvncserver: -rfbauth
26/07/2017 08:12:24 passing arg to libvncserver: /home/jsd/.vnc/passwd
26/07/2017 08:12:24 passing arg to libvncserver: -rfbport
26/07/2017 08:12:24 passing arg to libvncserver: 5900
26/07/2017 08:12:24 x11vnc version: 0.9.13 lastmod: 2011-08-10  pid: 50206
26/07/2017 08:12:24 -auth guess: using default XAUTHORITY for display='unset'
26/07/2017 08:12:24 XOpenDisplay("") failed.
26/07/2017 08:12:24 Trying again with XAUTHLOCALHOSTNAME=localhost ...
26/07/2017 08:12:24 
26/07/2017 08:12:24 *** XOpenDisplay failed. No -display or DISPLAY.
26/07/2017 08:12:24 *** Trying ":0" in 4 seconds.  Press Ctrl-C to abort.
26/07/2017 08:12:24 *** 1 2 3 4 
26/07/2017 08:12:28 *** XOpenDisplay of ":0" successful.
26/07/2017 08:12:28 
26/07/2017 08:12:28 Using X display :0
26/07/2017 08:12:28 rootwin: 0x281 reswin: 0x1a00001 dpy: 0x1cbc6f0
26/07/2017 08:12:28 
26/07/2017 08:12:28 ------------------ USEFUL INFORMATION ------------------
26/07/2017 08:12:28 
26/07/2017 08:12:28 Wireframing: -wireframe mode is in effect for window moves.
26/07/2017 08:12:28   If this yields undesired behavior (poor response, painting
26/07/2017 08:12:28   errors, etc) it may be disabled:
26/07/2017 08:12:28    - use '-nowf' to disable wireframing completely.
26/07/2017 08:12:28    - use '-nowcr' to disable the Copy Rectangle after the
26/07/2017 08:12:28      moved window is released in the new position.
26/07/2017 08:12:28   Also see the -help entry for tuning parameters.
26/07/2017 08:12:28   You can press 3 Alt_L's (Left "Alt" key) in a row to 
26/07/2017 08:12:28   repaint the screen, also see the -fixscreen option for
26/07/2017 08:12:28   periodic repaints.
26/07/2017 08:12:28 
26/07/2017 08:12:28 XFIXES available on display, resetting cursor mode
26/07/2017 08:12:28   to: '-cursor most'.
26/07/2017 08:12:28   to disable this behavior use: '-cursor arrow'
26/07/2017 08:12:28   or '-noxfixes'.
26/07/2017 08:12:28 using XFIXES for cursor drawing.
26/07/2017 08:12:28 GrabServer control via XTEST.
26/07/2017 08:12:28 
26/07/2017 08:12:28 Scroll Detection: -scrollcopyrect mode is in effect to
26/07/2017 08:12:28   use RECORD extension to try to detect scrolling windows
26/07/2017 08:12:28   (induced by either user keystroke or mouse input).
26/07/2017 08:12:28   If this yields undesired behavior (poor response, painting
26/07/2017 08:12:28   errors, etc) it may be disabled via: '-noscr'
26/07/2017 08:12:28   Also see the -help entry for tuning parameters.
26/07/2017 08:12:28   You can press 3 Alt_L's (Left "Alt" key) in a row to 
26/07/2017 08:12:28   repaint the screen, also see the -fixscreen option for
26/07/2017 08:12:28   periodic repaints.
26/07/2017 08:12:28 
26/07/2017 08:12:28 XKEYBOARD: number of keysyms per keycode 7 is greater
26/07/2017 08:12:28   than 4 and 51 keysyms are mapped above 4.
26/07/2017 08:12:28   Automatically switching to -xkb mode.
26/07/2017 08:12:28   If this makes the key mapping worse you can
26/07/2017 08:12:28   disable it with the "-noxkb" option.
26/07/2017 08:12:28   Also, remember "-remap DEAD" for accenting characters.
26/07/2017 08:12:28 
26/07/2017 08:12:28 X FBPM extension not supported.
26/07/2017 08:12:28 X display is capable of DPMS.
26/07/2017 08:12:28 --------------------------------------------------------
26/07/2017 08:12:28 
26/07/2017 08:12:28 Default visual ID: 0x21
26/07/2017 08:12:29 Read initial data from X display into framebuffer.
26/07/2017 08:12:29 initialize_screen: fb_depth/fb_bpp/fb_Bpl 24/32/7680
26/07/2017 08:12:29 
26/07/2017 08:12:29 X display :0 is 32bpp depth=24 true color
26/07/2017 08:12:29 
26/07/2017 08:12:29 Listening for VNC connections on TCP port 5900
26/07/2017 08:12:29 Listening for VNC connections on TCP6 port 5900
26/07/2017 08:12:29 listen6: bind: Address already in use
26/07/2017 08:12:29 Not listening on IPv6 interface.
26/07/2017 08:12:29 
26/07/2017 08:12:29 Xinerama is present and active (e.g. multi-head).
26/07/2017 08:12:29 Xinerama: number of sub-screens: 1
26/07/2017 08:12:29 Xinerama: no blackouts needed (only one sub-screen)
26/07/2017 08:12:29 
26/07/2017 08:12:29 fb read rate: 903 MB/sec
26/07/2017 08:12:29 fast read: reset -wait  ms to: 10
26/07/2017 08:12:29 fast read: reset -defer ms to: 10
26/07/2017 08:12:29 The X server says there are 16 mouse buttons.
26/07/2017 08:12:29 screen setup finished.
26/07/2017 08:12:29 

The VNC desktop is:      ubuntu:0
PORT=5900

******************************************************************************
Have you tried the x11vnc '-ncache' VNC client-side pixel caching feature yet?

The scheme stores pixel data offscreen on the VNC viewer side for faster
retrieval.  It should work with any VNC viewer.  Try it by running:

    x11vnc -ncache 10 ...

One can also add -ncache_cr for smooth 'copyrect' window motion.
More info: http://www.karlrunge.com/x11vnc/faq.html#faq-client-caching

ubuntu 启动x11vnc 时候报错  待解决