Replace blank lines with specific text in Notepad ++

Question

For example I have a text

Line1

Line3

Line5

Line6

And I need to replace the blank lines with a specific text, e.g. CoolText so the result would be

Line1
CoolText
Line3
CoolText
Line5
CoolText
Line6

How to accomplish this?

Answer 1

You can use the extended replacement feature in NotePad++. Search for doubled carriage return/line feed pairs (\r\n\r\n), and replace them with a carriage return/line feed pair, the replacement text, and another CR/LF pair (\r\nCoolText\r\n).

Here's the text file with the dialog set up for the replacement, before clicking "Replace All":

Here are the results after clicking "Replace All":