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Add a Icon image to a window permenately

   Using xwininfo  get the windowid, and its size and position (to root window)
   NOTE: make shure you pick the appropriate child of the window.

   xloadimage -windowid 0xWINDOWID -at X,Y  IMAGE

   xrefresh -geometry WIDTHxHEIGHT+X+Y 

 This sets the background pixmap of the window to the a blank white image
the size of the window with a copy of the IMAGE at the prosition given.
The xrefresh will then get the client to redraw the other parts of the window.
This image will be refreshed automatically by the X server whenever required.
Do not use this technique for a large window to save server memory.

 Example add to the current xterms window:

    image=${1:-/usr/include/bitmaps/std/finger.xbm}
    child=`xwininfo -children -id $WINDOWID | sed -n 's/^ *\(0x[^ ]*\).*/\1/p'`
    xloadimage -windowid $child  -at 420,10  $image

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To kill a specific client
  Kill a client that is runing on the display without asking the user to
do so.

 Look for a xv client. NOTE this could easily get it wrong.

   xkill -id `xwininfo -all -children -root | awk '/\"xv\"/ {print $1; exit}'`

   a winkill    'xkill -id `xwininfo -all -children -root |\\\
                    awk '\''/\"\!:*\"/ {print $1; exit}'\''`'

 Better to use the windows title for xwininfo. This must however be exact
so a version or patch upgrade could invalidate it.

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To find a windows title, default icon id, etc
  use
    xprop -id $WINDOWID

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Colormap hints

  xv -clear

    To remove unused color table entries. This does not include the colors
  used by the root pixmap.

  xv -root -quit

    Clear unused colors including the root pixmap colors.

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