note 114916 added to function.eval

Modified version of Daniele Mams's answer: I change the $number definition to accept scientific notation like in: http://stackoverflow.com/questions/638565/parsing-scientific-notation-sensibly <?php function calc($equation) { // Remove whitespaces $equation = preg_replace('/\s+/', '', $equation); echo "$equation\n"; $number = '(-?(?:0|[1-9]\d*)(?:\.\d*)?(?:[eE][+\-]?\d+)?)'; // What is a number $functions = '(?:abs|atan|ceil|cos|exp|gmp_fact|intval|log(10)?|rand|round|sin|sqrt|tan)'; // Allowed PHP functions $operators = '[\/*\^\+-]'; // Allowed math operators $regexp = '/^([+-]?('.$number.'|'.$functions.'\s*\((?1)+\)|\((?1)+\))(?:'.$operators.'(?1))?)+$/'; // Final regexp, heavily using recursive patterns if (preg_match($regexp, $equation)) { $equation = preg_replace('!pi|π!', 'pi()', $equation); // Replace pi with pi function echo "$equation\n"; eval('$result = '.$equation.';'); } else { $result = false; } return $result; } ?> ---- Server IP: 72.52.91.14 Probable Submitter: 5.96.92.210 ---- Manual Page -- http://php.net/manual/en/function.eval.php Edit -- https://master.php.net/note/edit/114916 Del: integrated -- https://master.php.net/note/delete/114916/integrated Del: useless -- https://master.php.net/note/delete/114916/useless Del: bad code -- https://master.php.net/note/delete/114916/bad+code Del: spam -- https://master.php.net/note/delete/114916/spam Del: non-english -- https://master.php.net/note/delete/114916/non-english Del: in docs -- https://master.php.net/note/delete/114916/in+docs Del: other reasons-- https://master.php.net/note/delete/114916 Reject -- https://master.php.net/note/reject/114916 Search -- https://master.php.net/manage/user-notes.php