1{ 2 # concat with null argument data expression 3 # empty configs are not accepted by Kea 4 "Dhcp4": { 5 "valid-lifetime": 1800, 6 "client-classes": [ 7 # null left argument 8 /// match: concat('', suffix(option dhcp.host-name, 3)) 9 { 10 "name": "null-left" 11 }, 12 /// subclass selector 'com' 13 { 14 "name": "sub#null-left#0", 15 /// from: match concat('', suffix(option dhcp.host-name, 3)) 16 /// data: 'com' 17 "test": "substring(option[12].hex,-3,all) == 'com'" 18 }, 19 # null right argument 20 /// match: concat(suffix(option dhcp.host-name, 3), substring('foobar', 0, 0)) 21 { 22 "name": "null-right" 23 }, 24 /// subclass selector 'org' 25 { 26 "name": "sub#null-right#1", 27 /// from: match concat(suffix(option dhcp.host-name, 3), substring('foobar', 0, 0)) 28 /// data: 'org' 29 "test": "substring(option[12].hex,-3,all) == 'org'" 30 } 31 ] 32 } 33} 34