echo "0 "Service Check Name in Check MK" - Port is open"
u can name service check name as u wish to appear in checkmk.
checkport '1.2.3.4' 104
would check dicom port if its open
you can change ip / hostbame and port whatever u need to check,
install on agent host
copy check to /usr/lib/check_mk_agent/local/
chmod +x /usr/lib/check_mk_agent/local/namelikeyourcheckname