1# exists boolean expression 2 3# empty configs are not accepted by Kea 4default-lease-time 1800; 5 6# use exists in a reductible match if 7class "reductible" { 8 match if exists host-name; 9} 10 11# if test is a boolean too 12if exists host-name { 13 log(info, concat("hostname:", option host-name)); 14} 15 16