How to use sed to remove the last n lines of a file

Question

I want to remove some n lines from the end of a file. Can this be done using sed?

For example, to remove lines from 2 to 4, I can use

$ sed          


        

Answer 1

sed -n ':pre
1,4 {N;b pre
    }
:cycle
$!{P;N;D;b cycle
  }' YourFile

posix version