check() {

	# get listening sockets

	local listen=$(lsof -c apache2 -a -Pni tcp -Fn 2>/dev/null \

		| grep '^n' | grep -v -- '->' | cut -c 2- \

		| sort -n | uniq)

	if [ -z "${listen}" ]; then

		ewarn "Apache2 not listening on any address :-("

	else

		einfo "Apache2 listening on:"

		eindent

		# loop through ip+port list

		for ip_port in ${listen}; do

			einfon "${ip_port}, "

			local ip=${ip_port%:*}

			local port=${ip_port#*:}

			case ${port} in

				# known HTTP ports

				80|81|8080)

					echo -n 'trying HTTP: '

					local res=$(echo -en "HEAD ${CHECK_URI:-/} HTTP/1.0\n\n" \

						| nc -w 3 ${ip} ${port} 2>/dev/null \

						| head -n 1)

					;;

				# known HTTPS ports

				443)

					echo -n 'trying HTTPS: '

					local res=$(echo -en "HEAD ${CHECK_URI:-/} HTTP/1.0\n\n" \

						| openssl s_client -quiet -connect ${ip_port} 2>/dev/null \

						| head -n 1)

					;;

				# unknown ports

				*)

					echo -n "no idea how to handle port ${port}"

					;;

			esac

			# did we get a result?

			if [ -n "${res}" ]; then

				echo "${res}"

				eend 0

			else

				echo ":-("

				eend 1

			fi

		done

		eoutdent

	fi

}