doc/make-snapshot.sh

   1 #! /bin/sh
   2 #
   3 # Copyright (C) 2013-2022 by Werner Lemberg.
   4 #
   5 # This file is part of the ttfautohint library, and may only be used,
   6 # modified, and distributed under the terms given in `COPYING'.  By
   7 # continuing to use, modify, or distribute this file you indicate that you
   8 # have read `COPYING' and understand and accept it fully.
   9 #
  10 # The file `COPYING' mentioned in the previous paragraph is distributed
  11 # with the ttfautohint library.
  12 #
  13 #
  14 # make-snapshot.sh <application> [<application-options>...] > filename
  15 #
  16 # Make a snapshot from an application's start window and save it to a file.
  17 # This needs X11 and ImageMagick's `import' tool.
  18 #
  19 # This script is very simple.  Some possible problems:
  20 #
  21 # o In case the program doesn't create a visible X11 window, you have to
  22 #   abort the script with ^C.
  23 #
  24 # o It fails for intelligent applications like `firefox' in case they are
  25 #   already run, since firefox replaces the process with a new window of the
  26 #   already running instance.
  27 #
  28 # o It loops forever for programs like `k3b' that spawns itself, thus
  29 #   having a different process ID for the visible window.
  30
  31
  32 # This script uses ideas from the now defunct site
  33 # http://blog.chewearn.com/2010/01/18/find-window-id-of-a-process-id-in-bash-script/.
  34
  35 if [ $# -eq 0 ]; then
  36   echo "Usage: $0 application [options...] > imagename"
  37   exit 1
  38 fi
  39
  40
  41 find_WID()
  42 {
  43   # Get all windows with the name $APP (ignoring case).
  44   xwininfo -root -tree 2>/dev/null \
  45   | grep -i $1 \
  46   | while read DATA; do
  47       # Extract Window ID.
  48       WID=`echo $DATA | awk '{print $1}'`
  49
  50       # Check whether the window's PID is matching the application's PID.
  51       # We use `=' for the comparison instead of `-eq' because `xprop'
  52       # can return non-numerical values.
  53       if [ `xprop -id $WID _NET_WM_PID | awk '{print $3}'` = $PID ]; then
  54         # Check whether window is displayed actually.
  55         if [ "`xwininfo -id $WID | grep 'IsViewable'`" != '' ]; then
  56           echo $WID
  57           return
  58         fi
  59       fi
  60     done
  61 }
  62
  63
  64 # Start program in background and get its process ID.
  65 $@ &
  66 PID=$!
  67
  68 sleep 1
  69
  70 # Get application name.
  71 APP=`ps --no-header -o comm -p $PID`
  72 if [ "$APP" == "" ]; then
  73   echo "Couldn't start application \`$@'"
  74   exit 1
  75 fi
  76
  77 # Loop until program has displayed a window
  78 # so that we can actually get the Windows ID.
  79 while [ "$WID" == "" ]; do
  80   WID=`find_WID $APP`
  81   sleep 1
  82 done
  83
  84 # Make snapshot.
  85 import -silent -window $WID png:-
  86
  87 kill $PID
  88
  89 # eof