#!/usr/bin/env ruby

require 'ostruct'
require 'optparse'

configuration = OpenStruct.new

configuration.limit = 80

OptionParser.new do |options|
  options.banner = "USAGE: #{File.basename($0)} [OPTIONS]"
  help_string = 'Read from stdin and dump each truncated line to limit -l [N] to stdout.'
  parser = OptionParser::DecimalInteger
  options.on('-l', '--limit [N]', parser, help_string) do |value|
    configuration.limit = value
  end
end.parse!

STDIN.each_line do |line|
  puts line[0..configuration.limit]
end