$re = '/Initial commit|Merge [^\r\n]+|(?:(build|chore|ci|docs|feat|fix|perf|refactor|revert|style|test|BREAKING CHANGE)(\(\w+\))?!?: ([\w ]+))(?:\r?\n){0,2}([\w\s]+)(?:\r?\n([\w-]+): (\w+)|$)/m';
$str = '#1
build(Breaking): la asdf asdf asdf
asdfasdf asdf asdf
asdf
asdf
asdf
asdf
asdf
asdf
aef asdf asdf
#2
build(Breaking): la asdf asdf asdf
asdfasdf asdf asdf
asdf
asdf
asdf
asdf
asdf
asdf
aef asdf asdf
asdf-asdf: asdf
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php