#!/bin/bash

if [ -z $1 ]; then
    echo  "Use $0 <dim max> <thumbnail prefix>";
    exit;
fi

if [ -z $2 ]; then
    MYPREFIX="thumb_";
else
    MYPREFIX=$2;
fi

for i in `echo * |sed "s/ /n/g"|grep -i jpg`; do
    if [ -f "$i" ]; then
        echo $i;
        convert -filter lanczos -geometry $1x$1 $i $MYPREFIX$i;
    else
        echo "Errmmm... file -> $i < - does not exist...";
    fi
done

echo 
echo "Done..."
echo