nlines

#!/usr/bin/ruby
#
# In your favorite programming language, write a program to read a multiple line text file and write the 
# N longest lines to a new file. Where N and the file to be read are specified on the command line.

require 'rubygems'
require 'choice'

Choice.options do
  header ''
  header 'Specific options:'

  option :input_file_name, :required => true do
    short '-f'
    long '--file=FILE'
    desc 'The file containing the lines'
  end

  option :output_file_name, :required => true do
    short '-o'
    long '--output=FILE'
    desc 'The output file'
  end

  option :line_count, :required => true  do
    short '-c'
    long '--count=COUNT'
    desc 'The amount of lines to save'
  end


  separator ''
  separator 'Common options: '

  option :help do
    long '--help'
    desc 'Show this message'
  end
end

input_file_name = Choice.choices[:input_file_name]
output_file_name = Choice.choices[:output_file_name]
line_count = Choice.choices[:line_count]
data = {}

lines = IO.read(input_file_name).split(/\n/)
lines.each do |line| 
    data[line.length] ? data[line.length].push(line) : data[line.length] = [line]
end

output_file_contents = data.sort.reverse.collect{|key,value| value }.flatten.slice(0,line_count.to_i).join("\n")

File.open(output_file_name, "w+") do |f|
	f.syswrite(output_file_contents)
end