batch_expand_shortened_url.sh

#!/bin/bash

filename=~/path/to/shortened_input.txt
exec 4<$filename
    while read -u4 p ; do
        expanded=$(curl -sI $p | sed -n 's/Location: *//p')
            if [ ${#expanded} > 0 ]
            then
                echo $expanded >> ~/path/to/expanded_output.txt;
            else
                echo $p >> ~/path/to/expanded_output.txt;
            fi
done