Notepad++ use both regular expressions and extended search

Question

I need to find all \r\n that do not precede the letter M;
Seems I can't do this:

\r\n[^M]

I can only do \r\n with extended search selected or [^M] with regular expressions selected; but not together.

Answer 1

You should instead use this regex:

\R(?!M)

Explanation:

• \R Any Unicode newline sequence.
• (?!M) Negative Lookahead: Assert "M" cannot be matched.

Answer 2

\r\n is valid with Regular expression checked in the Find tab too - i.e. not just with Extended checked: why not just use \r\n[^M] with Regular expression checked?

Given the following test text...

whatever
M
whatever
G
foo

..., \r\n[^M] yields the expected results below...

Search "\r\n[^M]" (3 hits in 1 file)
  new  2 (3 hits)
    Line 2: M
    Line 3: whatever
    Line 4: G

..., the matches being at the ends of the matched lines of course.