#!/bin/bash
width=""
height=""
prepend=""
append=""
while getopts 'h:w:p:a:' OPTION
do
  case $OPTION in
  w)	width="$OPTARG"
        ;;
  h)	height="$OPTARG"
        ;;
  p)	prepend="$OPTARG"
  	;;
  a)	append="$OPTARG"
  	;;
  ?)	printf "Usage: %s: [-w width] [-h height] [-p prepend_to_filename] [-a append_to_filename] [FILE]... FILE\n" $(basename $0) >&2
        exit 2
        ;;
  esac
done
shift $(($OPTIND - 1))

if [ $width ]
then
	dims="$width"
else
	if [ -z $height ]
	then
		printf "Usage: %s: [-w width] [-h height] [-p prepend_to_filename] [-a append_to_filename] [FILE]... FILE\n" $(basename $0) >&2
		exit 2
	fi
fi

if [ $height ]
then
	dims="${dims}x${height}"
fi

for file in $@
do
	echo "Processing $file..."
	newfile=$(basename $file)
	dir="$(dirname $file)/"

	if [ $append ]
	then
		newfile="$dir${newfile%.*}$append.${newfile##*.}"
	fi

	if [ $prepend ]
	then
		newfile="$dir$prepend$(basename $newfile)"
	fi

	$(convert -thumbnail $dims $file $newfile)
done