Scanner output sorter

sort.sh

#!/bin/bash
# Sorts the images which are scanned by a scanner in the following way: (last file index is 20 for e.g.)
# pages 1,3,5,... are named scan0000.jpg, scan0001.jpg, scan0002.jpg,...
# then pages 2,4,6,... are named scan0020.jpg, scan0019.jpg, scan0018.jpg, ...

# The script sorts them in range 000 to 020

mkdir -p final
end=`ls scan* -1 | wc -l`
flag=0
for i in `eval echo {000..$((end-1))}`; do # max range = 999; add more 0 for more range
	if ((flag%2==0)); then
		mv `ls scan* -1 | head -n1` "final/scan$i.jpg"
	else
		mv `ls scan* -1 | tail -n1` "final/scan$i.jpg"
	fi
	((flag++))
done