Slurping can be a problem if your files are large. This one-liner avoids that by using -n instead of -p: 

perl -i -ne '/^$/ or print' foo.txt

[download]
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."

In reply to Re: how to use matching operator on newlines by BrowserUk
in thread how to use matching operator on newlines by redss

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