How do I write a Vim search pattern that matches text spanning multiple lines?

Explanation

Vim's regex engine normally treats . as matching any character except a newline, making cross-line matches impossible. The \_ prefix turns any character class or . into a newline-aware version, enabling true multi-line search patterns.

How it works

• \_. — matches any single character including newlines (unlike . which stops at end-of-line)
• \_.{-} — non-greedy match of any characters including newlines ({-} is Vim's non-greedy quantifier)
• \_s — matches any whitespace including newlines (\s only matches inline whitespace)
• \_[abc] — matches a, b, c, or a newline

Example

Given a buffer:

function foo(
    arg1,
    arg2
)

To find foo(...) even when the argument list spans multiple lines, use the non-greedy form:

/foo(\_.{-})

The greedy \_.* would match from the first ( all the way to the last ) in the file. Always prefer {-} with multi-line patterns to avoid over-matching.

Tips

• Combine with \zs / \ze to narrow the highlighted region: /foo(\zs\_.{-}\ze) highlights only the argument content
• \_s\+ is a useful pattern for collapsing runs of whitespace that may include blank lines
• Use :set hlsearch and n / N to visually confirm multi-line match boundaries
• In substitute commands, \n in the replacement inserts a literal newline, while \_. in the pattern matches across newlines