sed: replace range with file content

Question

How can I replace a range with the content of a file, once? Using the sed script

/<start>/,/<end>/{
  d
  r <filename>
}

reads the file into every line. I doesn't need to be done with sed, of course, but I have the feeling that there isn't much missing.

Answer 1

Rearrange the commands to get the desired output:

    /<start>/,/<end>/{
      /<end>/r <filename>
      d
    }