How can I replace multiple empty lines with a single empty line in bash?

Question

I have a file that contains:

something



something else

something else again

I need a bash command, sed/grep w.e that will produce the fo

Answer 1

I just solved this problem by sed. Even if this is a 7 years old question, someone may can here for help, so I am writing my solution by sed here:

sed 'N;/^\n$/D;P;D;'