Can I use the sed command to replace multiple empty line with one empty line?

I know there is a similar question in SO How can I replace mutliple empty lines with a single empty line in bash?. But my question is can this be implemented by just using the sed command?

Thanks

How do you add a blank line using sed?

To answer the question as asked, you'd have to do sed 's/pattern. */&\n/' , otherwise you'll insert the newline right after the match instead of at the end of the line.

How do you use sed multiple times?

You can tell sed to carry out multiple operations by just repeating -e (or -f if your script is in a file). sed -i -e 's/a/b/g' -e 's/b/d/g' file makes both changes in the single file named file , in-place.

Give this a try: