define command{
	command_name 	check_string
	command_line 	$USER1$/check_http -H $HOSTADDRESS$ -s $ARG1$
}

Exemple de service utilisant la commande ci-dessus.

define service{
	use 		Template-Website-Service
	host_name 	exchange.nagios.org
	service_description  website defacement check
	check_command       check_string!nagios
}