add_env

this is the error I get.
/srv/chef/cookbooks/system/libraries/add_env_var.rb:1:in `system': wrong number of arguments (ArgumentError)


Module system

def add_env_var(variable, path)
  envfile = "/etc/profile.d/99generic.sh"
  foundvar = false
  arr = IO.readlines( envfile ) if File::exists?( envfile )
  length = arr.length - 1

  for i in 0..length
    if arr[i][variable] then
      line = arr[i].chomp.split( '=' )
      paths = line[1].split( ':' ) << path
      arr[i] = line[0] + "=" + paths.uniq.join( ':' ) + "\n"
      foundvar = true
      break
    end
  end

  if !foundvar then
    arr << "export #{variable}=#{path}"
  end

  aFile = File.new( envfile, "w" )
  aFile.syswrite( "#{arr.flatten}" )
end