My simple downloader doesn't work

Hello,

I’m learning Ruby for some time. Today I started to write simple code
which will download specified files from specified servers but it
doesn’t work. It always showing me error 500 when code is going to
download file. This is code:

equire ‘net/ftp’
require ‘net/http’

class Get

def initialize(resource)
if resource=~/http://|ftp:///
@resource=resource
@status=0
@type = resource[0…1].to_s
end
end

def get
case (@type)
when “ht”
@sock = Net.HTTP.new(@resource)
@sock.getbinaryfile(“index.html”,1024)
when “ft”
index = (@resource[6…-1].index("/")+5)
last = (@resource.size - @resource.reverse.index("/")-1)
ftp = Net::FTP.new(@resource[6…index])
ftp.login
ftp.chdir(@resource[(index+2)…last])
ftp.get(@resource[(last+1)…-1] , @resource[(last+1)…-1])
ftp.close
end
end

end

get = Get.new(“ftp://sunsite.icm.edu.pl/pub/Linux/slackware/
slackware-12.0/CHECKSUMS.md5.asc”)
get.get