1) { $counter = 9; }'); */ // ------------------------------------------------------------------------------------------- // // Display nice message about this test-page for eval // require_once('common.php'); echo $header; echo <<Example code to show how eval() works, both from variable and from database.

Read the PHP manual for details: http://php.net/manual/en/function.eval.php

--
-- SQL to create the database table
--
 CREATE TABLE Phpcode (
	id INT NOT NULL PRIMARY KEY,
	code VARCHAR(500) NOT NULL
);

INSERT INTO Phpcode (id, code)
VALUES 
(1 , '\$counter++;'), 
(2 , '\$counter += 1;'), 
(3 , '\$counter++; if(\$counter >1) { \$counter = 9; }');

Lets try out the example.

EOD; // ------------------------------------------------------------------------------------------- // // First try to execute the same thing from a string. // // Since nowdox is not available (need PHP 5.3.0) I will instead prepend each $ with a \ // to prevent it from being evaluated. It works fine. But nowdoc would be better. // // http://php.net/manual/en/language.types.string.php (nowdoc, heredoc) // http://php.net/manual/en/function.eval.php // $code1 = "\$counter++;"; $code2 = '$counter += 1;'; $code3 = <<1) { \$counter = 9; } EOD; // ---------------------------------------------------------------------------- // // Evaluate the code segments using eval() // // http://php.net/manual/en/function.eval.php // echo "

eval() using variables. The following code should result in a line saying: 0129

"; $counter = 0; echo $counter; eval($code1); echo $counter; eval($code2); echo $counter; eval($code3); echo $counter; // ---------------------------------------------------------------------------- // // Connect to the database to retrieve and evaluate the code segments // // http://php.net/manual/en/function.eval.php // // Connect to database require_once('config.php'); $mysqli = new mysqli(DB_HOST, DB_USER, DB_PASSWORD, DB_DATABASE); !mysqli_connect_error() or die("Connect failed: ".mysqli_connect_error()."
"); // Perform query $query = "SELECT * FROM Phpcode;"; $res = $mysqli->query($query) or die("Could not query database, query =
{$query}

{$mysqli->error}"); // Use resultset echo "

eval() using database. The following code should result in a line saying: 0129

"; $counter = 0; echo $counter; while($row = $res->fetch_object()) { eval($row->code); echo $counter; } $res->close(); $mysqli->close(); // ---------------------------------------------------------------------------- // // Good work // echo "

I am so great :)

"; echo $footer; exit; ?>