How do I write a Vim regex that matches any character including newlines for multi-line pattern matching?

Explanation

In Vim's regular expressions, . matches any character except a newline — the same as in most regex engines. To match any character including newlines, use \_. : the \_ prefix forces the character class to include the newline character. This unlocks true multi-line pattern matching directly in Vim's built-in search and substitution.

How it works

• . — matches any single character except \n
• \_. — matches any single character including \n
• The \_ modifier generalises to other classes: \_s matches whitespace plus newlines; \_[a-z] matches lowercase letters plus newlines

Example

Given text:

begin
  first line
  second line
end

Find everything from begin to end across lines:

/begin\_.\{-}end

\_.\{-} is the non-greedy form: it stops at the first end it finds. The greedy form \_.* would stretch to the last end in the buffer.

Tips

• Use \_.\{-} (non-greedy) rather than \_.* (greedy) for most multi-line matches to avoid overshooting
• Works in substitutions: :%s/begin\_.\{-}end/REPLACED/ replaces the entire multi-line block
• \n in a search pattern also matches newlines and is sometimes simpler for literal newline positions, but \_. is more composable when combined with repetition operators
• For line-range operations, :g/begin/.,/end/ is often a cleaner alternative that works without crafting a multi-line regex