posix-looking-at

posix-looking-at is a built-in function in `C source code'.

(posix-looking-at REGEXP)

Return t if text after point matches regular expression REGEXP.
Find the longest match, in accord with Posix regular expression rules.
This function modifies the match data that `match-beginning',
`match-end' and `match-data' access; save and restore the match
data if you want to preserve them.