Crappy benchmark for `IO#each_line` performance. In local tests, I provided a file containing 100 copies of `/usr/share/dict/words`.

each-line-benchmark.rb

File.open(ARGV.first).each_line do |line|
  1 + 1
end

out = ''
start = Time.now
File.open(ARGV.first).each_line do |line|
  out << line
end
read_end = Time.now
puts out
final = Time.now

$stderr.puts "Reading: #{read_end - start}"
$stderr.puts "Writing: #{final - read_end}"
$stderr.puts "Total: #{final - start}"