Module 0x1 | Basic Ruby Kung Fu

    Here are some different ways to get terminal size from ruby:

    • By IO/console standard library
    • By readline standard library
    2. Readline.get_screen_size
    • By environment like IRB or Pry
    • By tput command line 
    1. [`tput cols`.to_i , `tput lines`.to_i]

    Console with tab completion

    We can’t stop being jealous of Metasploit console (msfconsole), where we take a rest from command line switches. Fortunately, here is the main idea of console tab completion in ruby:

    • Readline

    console-basic1.rb

    Now run it and try out the tab completion!

    console-basic2.rb

    1. require 'readline'
    3. # Prevent Ctrl+C for exiting
    5. # List of commands
    6. CMDS = [ 'help', 'rubyfu', 'ls', 'exit' ].sort
    10.     proc do |str|
    11.       case 
    12.       when Readline.line_buffer =~ /help.*/i
    13.     puts "Available commands:\n" + "#{CMDS.join("\t")}"
    14.       when Readline.line_buffer =~ /rubyfu.*/i
    15.     puts "Rubyfu, where Ruby goes evil!"
    16.       when Readline.line_buffer =~ /ls.*/i
    17.     puts `ls`
    18.     puts 'Exiting..'
    19.     exit 0
    21.     CMDS.grep( /^#{Regexp.escape(str)}/i ) unless str.nil?
    22.       end
    23.     end
    26. Readline.completion_proc = completion        # Set completion process
    27. Readline.completion_append_character = ' '   # Make sure to add a space after completion
    29. while line = Readline.readline('-> ', true)  # Start console with character -> and make add_hist = true
    30.   puts completion.call
    31.   break if line =~ /^quit.*/i or line =~ /^exit.*/i

    Things can go much farther, like msfconsole, maybe?