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

Use python:

s = file("filename.txt").read()
while "\n\n\n" in s: s = s.replace("\n\n\n", "\n\n")
import sys
sys.stdout.write(s)