note 100644 added to errorfunc.constants

As a "dinosaur" developer working on getting up to speed on Php I am curious if there are specific error codes (messages) that can be returned from various Php functions? I am trying to use commands: opendir unlink copy closedir Are there error # codes that can be checked for one of the commands above to tell if it was successful or a specific code # so understand why it failed? ---- Server IP: 69.147.83.197 Probable Submitter: 205.188.116.143 ---- Manual Page -- http://www.php.net/manual/en/errorfunc.constants.php Edit -- https://master.php.net/note/edit/100644 Del: integrated -- https://master.php.net/note/delete/100644/integrated Del: useless -- https://master.php.net/note/delete/100644/useless Del: bad code -- https://master.php.net/note/delete/100644/bad+code Del: spam -- https://master.php.net/note/delete/100644/spam Del: non-english -- https://master.php.net/note/delete/100644/non-english Del: in docs -- https://master.php.net/note/delete/100644/in+docs Del: other reasons-- https://master.php.net/note/delete/100644 Reject -- https://master.php.net/note/reject/100644 Search -- https://master.php.net/manage/user-notes.php