def storlines(cmd, file) # :yield: line
      synchronize do
        with_binary(false) do
          conn = transfercmd(cmd)
          loop do
            buf = file.gets
            break if buf == nil
            if buf[-2, 2] != CRLF
              buf = buf.chomp + CRLF
            end
            conn.write(buf)
            yield(buf) if block_given?
          end
          conn.close
          voidresp
        end
      end
    rescue Errno::EPIPE
      # EPIPE, in this case, means that the data connection was unexpectedly
      # terminated.  Rather than just raising EPIPE to the caller, check the
      # response on the control connection.  If getresp doesn't raise a more
      # appropriate exception, re-raise the original exception.
      getresp
      raise
    end
Puts the connection into ASCII (text) mode, issues the given server-side
command (such as "STOR myfile"), and sends the contents of the file
named +file+ to the server, one line at a time. If the optional block is
given, it also passes it the lines.