#!/usr/bin/env ruby
require "readline"

class Alias

  def initialize
    @aliases = {}
  end

  def add nom, proc
    @aliases[nom] = proc
  end

  def cmd_exist? cmd
    @aliases.has_key? cmd
  end

  def call cmd, args=nil
    @aliases[cmd].call args
  end

  def show_aliases
    @aliases.each_key do |key|
      puts key
    end
  end
end

$alias = Alias.new

alias_p = Proc.new do |str|
  str[/^(\S+) */]
  name = $1
  cmd  = Proc.new do eval $' end
  $alias.add name, cmd
end

$alias.add "alias", alias_p

while ( line = Readline.readline '> ' )
  line[/^(\S+) */]
  cmd = $1
  args = $'
  if $alias.cmd_exist? cmd
    $alias.call cmd, args
  elsif cmd == 'help'
    $alias.show_aliases
  else
    puts "unknown command : #{cmd}"
  end
end