Count occurrences of a line in a file

count.coffee

fs = require 'fs'

fs.readFile 'letters.txt', (err, buffer) -> processFile buffer.toString()

processFile = (s) ->
  counts = {}
  lines = s.split '\n'
  for line in lines
    if counts[line]?
      counts[line]++
    else
      counts[line] = 1
  console.log JSON.stringify counts, null, 2