Question

Is it possible to get the line’s number using regex in Notepad++;

what I want to do, is replacing:

line1
line2
line3
etc..

with

1-line1
2-line2
3-line3
etc..

Answer 1

Notepad++ can do that by using the TextFX plugin. Select the lines and then select TextFX->TextFX Tools->Insert Line Numbers from the menu bar.

This will add line-numbers padded to 8 places with leading zeros. To get them in the form described in your question, you can use a regex-replace with these values:

search for: ^0+([0-9]+)\s

replace with: line\1-