Line counts are something that bean counters that do not understand software or rather quality software, use as a metric to determine how efficient their programmers are. I could quite easily pump out 1000 lines of crap code per day, and then have to change half of them 3 times and remove 30% to get to a predetermined level of quality, or I can average 1/4 of that, and produce code that has the requested level of quality from the start. Depending on the size of the project I may not code anything for days or weeks, while working through the design. Frequently the well thought out design has fewer lines of code and also has a higher level of quality (fewer lines of code usually means fewer chances to make a mistake).

However, to really answer your question, if some bean counter does ask for such a metric, I usually just give them a wc -l, or possibly, if I'm trying to make them think I've put some real work into the number, I have a script that does a glorified wc -l, but has an impressive name, and a hideous number of comand line switches and 'thinks' about the result for about 45 seconds to a minute, and then prints its result.