Quick Bash Script for Checking HTTP Headers

Whenever it comes to efficiently configure Web Servers and setting headers like ETAg, Cache-Control, or Expires and you have more than one server, you need to check them all since any user may hit different servers.

This script is meant to call wget on every IP returned by dig and display http response headers.
Usage is simple:

./script.sh http://www.example.com/ressource/with-long-cache-and-no-etag/big-image.jpg

Here's the code:

#!/bin/bash

BIN=${0##*/}
URL=${1?usage: $BIN url}
HOST=${URL#http://*}
REQ=${HOST#*/}
HOST=${HOST%%/*}

function check
{
	wget -S --header="Host: $HOST" "http://$line/$REQ" -O/dev/null
}

dig +short $HOST | \
while read line
do
	case $line in	
		[a-z]*)
		;;
		[0-9]*.[0-9]*.[0-9]*)
			echo === Testing $HOST with IP $line
			check $line
		;;
		*)
		;;
	esac
done