$re = '/Initial commit|Merge [^\r\n]+|(?:(?<type>build|chore|ci|docs|feat|fix|perf|refactor|revert|style|test|BREAKING CHANGE)(?<scope>\(\w+\))?(?<breaking_change>!?): (?<summary>[\w -]+))(?<=\v\v){0,2}(?<body>[\w\s-]+)(?<footer>(?<=\v\v)(?<footer_token>[\w-]+): (?<footer_value>[\w -]+)|$)/m';
$str = '#1
build(Breaking): la asdf asdf asdf
asdfasdf asdf asdf
asdf
asdf
asdf
asdf
asdf
asdf
aef asdf asdf
#2
build(Breaking)!: la asdf asdf asdf
asdfasdf asdf asdf
asdf
asdf
asdf
asdf
asdf
asdf
aef asdf asdf
asdf-asdf: asdf asfd asfd asdf
#3
build(Breaking): asdfasdf
#4
build(Breaking): la asdf asdf asdf
asdfasdf asdf asdf
asdf
asdf
asdf
asdf
asdf
asdf
aef asdf asdf
#5
build(Breaking): la asdf asdf asdf
asdfasdf asdf asdf
asdf
asdf
asdf
asdf
asdf
asdf
aef asdf asdf
asdf-asdf: asdf';
preg_match_all($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