get_server.sh

#!/usr/bin/env bash
# get_server.sh (c) NGINX, Inc. [v0.3 10-Jul-2019] Liam Crilly <liam.crilly@nginx.com>

if [ $# -lt 1 ]; then
	echo "USAGE: ${0##*/} [URI ...]"
	exit 1
fi

for site in "$@"; do
	echo -n "$site "
	# Try server header
	curl -I $site 2> /dev/null | grep -i ^server:
	if [ $? -eq 1 ]; then
		# Try 'get' behaviour
		echo -n "Fingerprint: "
		case `curl -siX get $site | head -1 | cut -f2 -d" "` in
			"200" | "301" | "302")
				echo "<CDN or BIG-IP>"
				;;
			"400")
				echo "NGINX"
				;;
			"405")
				echo "IIS"
				;;
			"501")
				echo "Apache"
				;;
			*)
				echo "<unknown>"
		esac
	fi
done