note 101523 added to regexp.reference.recursive

An unexpected behavior came up that introduced a very hard-to-track bug in some code I was working on. It has to do with the preg_match_all PREG_OFFSET_CAPTURE flag. When you capture the offset of a sub-match, it's offset is given _relative_ to it's parent. For example, if you extract the value between < and > recursively in this string: <this is a <string>> You will get an array that looks like this: Array ( [0] => Array ( [0] => Array ( [0] => <this is a <string>> [1] => 0 ) [1] => Array ( [0] => this is a <string> [1] => 1 ) ) [1] => Array ( [0] => Array ( [0] => <string> [1] => 0 ) [1] => Array ( [0] => string [1] => 1 ) ) ) Notice that the offset in the last index is one, not the twelve we expected. The best way to solve this problem is to run over the results with a recursive function, adding the parent's offset. ---- Server IP: 69.147.83.197 Probable Submitter: 208.86.47.254 ---- Manual Page -- http://www.php.net/manual/en/regexp.reference.recursive.php Edit -- https://master.php.net/note/edit/101523 Del: integrated -- https://master.php.net/note/delete/101523/integrated Del: useless -- https://master.php.net/note/delete/101523/useless Del: bad code -- https://master.php.net/note/delete/101523/bad+code Del: spam -- https://master.php.net/note/delete/101523/spam Del: non-english -- https://master.php.net/note/delete/101523/non-english Del: in docs -- https://master.php.net/note/delete/101523/in+docs Del: other reasons-- https://master.php.net/note/delete/101523 Reject -- https://master.php.net/note/reject/101523 Search -- https://master.php.net/manage/user-notes.php