# File lib/linecache.rb, line 379
  def size(file_or_script)
    cache(file_or_script)
    if file_or_script.kind_of?(String)
      file_or_script = unmap_file(file_or_script)
      return nil unless @@file_cache.member?(file_or_script)
      @@file_cache[file_or_script].lines[:plain].length
    else
      return nil unless @@script_cache.member?(file_or_script)
      @@script_cache[file_or_script].lines[:plain].length
    end
  end