$re = '/^(?:\[?([\w$#]+)]?\.)?\[?([\w$#]+)]?$/m';
$str = '-- should match
schema1.MyProcedure
MyProcedure
[MyProcedure]
[schema1].[MyProcedure]
[schema1].MyProcedure
MyProcedure_V1234
[MyProcedure_Ver1234]
schema1.[MyProcedure#V1234]
';
preg_match_all($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