Md5sum_ruby topic for Ruby Traversal folder simultaneous computing files

#!/usr/bin/ruby-w
#
require ' digest/md5 '

if argv.empty?
    Puts "Usgae: #$0 path"
    exit 0
End
dir_name=argv.shift

def dir_md5sum (path)
    md5s=array.new
    If File.directory? (path)
        Dir.new (path). Each do |file|
            Next if file =~/^\.+$/
            file= "#{path}/#{file}"
            if File.directory? ( File)
                dir_md5sum (file)
            elsif file.file? ( File)
                md5= "#{digest::md5.hexdigest (File.read (File)} #{file}"
                Md5s.push (MD5) end
    Elsif file.file? (path)
        Md5= "#{digest::md5.hexdigest (File.read (Path)} #{path}"
        Md5s.push (MD5)
    else
        puts "ivalid File type"
        exit 2
    end
    Md5s.each do |item|
        Puts item

    end

dir_md5sum (dir_name)