How do I match a pattern only if it is preceded by specific text?

Explanation

The \@<= atom is a positive lookbehind in Vim regex. It matches a pattern only when it is preceded by the specified text, without including the preceding text in the match.

How it works

• \(text\)\@<=pattern matches pattern only if preceded by text
• The lookbehind does not consume characters
• \@<! is the negative version (not preceded by)

Example

Match digits only when preceded by $:

/\$\@<=\d\+

In $100 and 200, this matches 100 but not 200.

Tips

• \@<= must follow a group: \(pattern\)\@<=
• Very magic version: /\v(\$)@<=\d+
• Lookbehinds can be slow with variable-length patterns
• Use \zs as a simpler alternative when possible