Prints the number of files and lines of code inside the given path with the given extension

numLines.rb

require 'find'

if ARGV.length != 2
  raise ArgumentError.new('Two arguments are required: path, extension')
end

path = ARGV[0]
extension = ARGV[1]

numFiles = 0
numLines = 0

Find.find(path) do |f|
  if File.file?(f) && File.fnmatch('*.' + extension, f)
    numFiles += 1
    numLines += File.new(f, 'r').readlines.length
  end
end

puts ".#{extension} - #{numFiles} files / #{numLines} lines of code"