flatten.rb

require 'pp'
a=[1,[2,[3]],4,5,[6,7,[8,9]]]
pp a.inject([]){|b,x| if Array===x then x.each {|y| b << y } else b << x end;b;}

numeric.rb

#ruby numeric.rb 10000000.12355
a,b=ARGV[0].split('.');p a.reverse.gsub(/(\d{3})(?=\d)/,'\1,').reverse + "." + b

resolve.rb

#ruby resolve.rb "Enumerable::Enumerator"
puts ARGV[0].split('::').inject(Kernel){|obj,str|obj.const_get(str)}