Expand URLs by following a single redirect

expand-url.sh

#!/bin/bash

main() {
    if [ -z $1 ]; then
        echo "Usage: expand-url URL"
        exit 1
    fi
    url=$1
    response $url | parse_redirect
}

response() {
    wget --max-redirect=0 -S $url 2>&1
}

parse_redirect() {
    ack "http.* " -o
}

main $1

exit 0