If you want to get the total line count for a project, you can simply combine the
find [directory] -name '*.php' -o -name '*.js' -o -name '*.css' | xargs wc -l
If you want a relative number, you can use
git commands to see how many lines were changed between two commits:
git diff --stat [reference commit]
Although line count isn’t a straight measure of code quality, discovering you have cut a code base size in half without touching features is always a good feeling.