take screenshots forever.

screenshot.sh

#!/bin/sh

# sec before start taking screenshot.
wait=5
# screenshot interval
interval=30
# output directory
outputdir=$HOME'/Desktop/ss/'`date +%Y-%m-%d`_`date +%H.%M.%S`

echo 'Interval:' $interval 'sec'

if [ ! -e $outputdir ]; then
    echo 'create directory ' $outputdir
    mkdir -p $outputdir
fi

echo 'waiting '$wait' sec..'
sleep $wait

i=0

while true
do
 i=`expr $i + 1`
 nm=$(printf %03d $i)
 echo $nm ': ' `date +%Y-%m-%d`\ `date +%H.%M.%S`
 /usr/sbin/screencapture -x -m -C -T0 $outputdir/$nm.png
    sleep $interval
done