#!/bin/sh
SIZES="120x500 300x225 400x300 600x450 800x600 1024x768 1600x1200 2400x1800"
STARTDIR="`pwd`"

[ "$1" ] && SIZES=$1

SCALED=yes

for SIZE in $SIZES; do
	cd "$STARTDIR"
	mkdir $SIZE
	cp *.jpg $SIZE
	cd $SIZE
	if [ "$SCALED"="yes" ]; then
		SCALED=no
		for FILE in *; do
			echo -n $FILE
			if ! nice -n 20 mogrify -verbose -geometry ${SIZE}'>' $FILE 2>&1 |egrep -q "[[:digit:]]+x[[:digit:]]+=>[[:digit:]]+x[[:digit:]]+"; then
				rm $FILE && echo "... not cached (small enough)."
			else
				echo "... cached at $SIZE."
				SCALED=yes
			fi
		done
	fi
done