Sort Word In String

#!/usr/bin/ruby
# coding: utf-8
def sort_word_in_string(s)
  a = s.split(/[ ,.]+/)
  a.sort_by {|e| e.downcase }
end
# test
DATA.each_line do |line|
  puts line
  puts sort_word_in_string(line.chomp)
end
__END__
a s d f g h j k l
q,w,e,r,t,y,u,i,o,p
z.x.c.v.b.n.m