Online PHP editor | refs for fuRZs

<?php $msg=(string)($_GET['message']?? $_POST['message'] ?? "no message!"); $answer=NULL; var_dump(getcwd()); register_shutdown_function(function()use(&$answer){ var_dump(getcwd()); file_put_contents(__DIR__.DIRECTORY_SEPARATOR.'msg.log.txt',json_encode(['answer'=>$answer,'$_GET'=>$_GET],JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_LINE_TERMINATORS ),FILE_APPEND|LOCK_EX); }); $matches=NULL; $isMatch=preg_match("/(\d+)\s*(\+|\-|\*|\/|\:)\s*(\d+)/",$msg,$matches); if($isMatch){ $l=(int)$matches[1]; $o=$matches[2]; $r=(int)$matches[3]; switch($o){ case '+': $res=$l+$r; break; case '-': $res=$l-$r; break; case '*': $res=$l*$r; break; case '/': case ':': $res=$l/$r; break; default: throw new \LogicException("invalid operator passed regex??!"); } $answer="!check {$res}"; echo $answer; }