superio.rb

require 'open-uri'

# == Feed me with:
# 
# Filename::   and I'll give you the file!
# URL::        and I'll give you the content!
# Any string:: and I'll give you a StringIO!
# An integer:: and I'll give you the stream for
#              the given integer file descriptor! 
# Any IO::     and I'll give you the same IO!
#
# == Set +type+ to:
#
# +:auto+::    and I'll figure it all out for you!
# +String+::   and you'll get a nice StringIO, no matter what!
# 
def SuperIO(io, type = :auto)
  return StringIO.new(io) if type == String
  raise "Unknown type" unless type == :auto
  case io
  when IO
    io
  when Integer
    IO.new(io)
  when String
    if File.exists?(io)
      File.new(io)
    elsif ((uri = URI.parse(io)).respond_to?(:open) rescue false)
      uri.open
    else
      StringIO.new(io)
    end
  else
    raise "Cannot convert to IO"
  end
end