# shows the contents of your current directory (more such commands available by FileUtils)
def ls(path='.')
  Dir[ File.join( path, '*' )].map{|res| res =~ /^#{path}\/?/; $' }
end
alias dir ls

# read file contents (also see ray for ruby source files ;) )
def cat(path)
  File.read path
end

# allows concise syntax like rq:mathn and reloading/requireing
def rq(lib)
  require lib.to_s
end

# reloading, hints from http://www.themomorohoax.com/2009/03/27/irb-tip-load-files-faster
def rerequire(lib)
  $".delete( "#{lib}.rb" )
  require( lib.to_s )
end
alias rrq rerequire

# load shortcut
def ld(lib)
  load lib.to_s + '.rb'
end

# returns the last lines, needed for some copy_ methods
def session_history(number_of_lines = context.instance_variable_get(:@line_no) )
  Readline::HISTORY.entries[-number_of_lines...-1]*"\n"
end

# restart irb
def reset!
  at_exit { exec$0 } # remember history
  exit
end

# just clear the screen
def clear
  system 'clear'
end

# change ruby version (requires rvm)
def use_ruby(which = nil)
  # test if installed
  unless `rvm -v` =~ /Seguin/
    raise 'Ruby Version Manager must be installed to use this command'
  end

  # show rubies if called without options
  if !which
    puts 'Availabe Rubies: ' +
          `rvm list`.scan( /^(?:  |=>) (.*) \[/ )*", "
    return
  end

  # get irb suffix
  rv = `rvm use #{which}` # e.g. => "\ninfo: Using ruby 1.9.2 p0\n"
                          # it does not change the ruby for the current user
  rv =~ /^.*Using(.*)\n/

  # if ruby is found, start it
  if $1
    ruby_name = File.split( $1 )[-1].tr(' ', '-')
    irbname = $0 + '-' + ruby_name# + '@global'
    at_exit { exec irbname } # remember history
    exit
  else
    puts "Sorry, that Ruby version could not be found."
  end
end
alias use use_ruby

# load debugger, inspired by rdp
def dbg
  begin
    require 'ruby-debug'
    debugger
  rescue LoadError => err
    throw "Sorry, unable to load ruby-debug gem for debugger: #{err}"
  end
end

class Object
  # display ri entry
  def ri(meth)
    ri_cmd = 'ri'
    if instance_of?( Kernel ) || instance_of?( Object )
      puts `#{ri_cmd} #{meth}`
    elsif is_a? Module
      puts `#{ri_cmd} #{self}.#{meth}`
    else
      puts `#{ri_cmd} #{self.class}##{meth}`
    end
  end
end

# J-_-L