note 87390 added to language.types.string

I commented on a php bug feature request for a string expansion function and figured I should post somewhere it might be useful: using regex, pretty straightforward: <?php function stringExpand($subject, array $vars) { // loop over $vars map foreach ($vars as $name => $value) { // use preg_replace to match ${$name} or $$name $subject = preg_replace(sprintf('/\$\{?%s\}?/', $name), $value, $subject); } // return variable expanded string return $subject; } ?> using eval() and not limiting access to only certain variables (entire current symbol table including [super]globals): <?php function stringExpandDangerous($subject, array $vars = array(), $random = true) { // extract $vars into current symbol table extract($vars); $delim; // if requested to be random (default), generate delim, otherwise use predefined (trivially faster) if ($random) $delim = '___' . chr(mt_rand(65,90)) . chr(mt_rand(65,90)) . chr(mt_rand(65,90)) . chr(mt_rand(65,90)) . chr(mt_rand(65,90)) . '___'; else $delim = '__ASDFZXCV1324ZXCV__'; // button mashing... // built the eval code $statement = "return <<<$delim\n\n" . $subject . "\n$delim;\n"; // execute statement, saving output to $result variable $result = eval($statement); // if eval() returned FALSE, throw a custom exception if ($result === false) throw new EvalException($statement); // return variable expanded string return $result; } ?> I hope that helps someone, but I do caution against using the eval() route even if it is tempting. I don't know if there's ever a truely safe way to use eval() on the web, I'd rather not use it. ---- Server IP: 209.41.74.194 Probable Submitter: 72.241.233.61 ---- Manual Page -- http://www.php.net/manual/en/language.types.string.php Edit -- https://master.php.net/note/edit/87390 Del: integrated -- https://master.php.net/note/delete/87390/integrated Del: useless -- https://master.php.net/note/delete/87390/useless Del: bad code -- https://master.php.net/note/delete/87390/bad+code Del: spam -- https://master.php.net/note/delete/87390/spam Del: non-english -- https://master.php.net/note/delete/87390/non-english Del: in docs -- https://master.php.net/note/delete/87390/in+docs Del: other reasons-- https://master.php.net/note/delete/87390 Reject -- https://master.php.net/note/reject/87390 Search -- https://master.php.net/manage/user-notes.php