Integer classLines = 0;
Integer triggerLines = 0;

for(ApexClass a : [Select Name, Body From ApexClass]){
List lines = a.Body.split(‘\n’);
classLines += lines.size();
System.debug(a.name + ‘:’ + lines.size());
}

for(ApexTrigger a : [Select Name, Body From ApexTrigger]){
List lines = a.Body.split(‘\n’);
triggerLines += lines.size();
System.debug(a.name + ‘:’ + lines.size());
}

system.debug(‘Apex Class lines: ‘ + classLines);
system.debug(‘Apex Trigger lines: ‘ + triggerLines);
system.debug(‘Apex Total lines: ‘ + (classLines+ triggerLines));