+// Bail on old versions of PHP. Pretty much every other file in the codebase
+// has structures (try/catch, foo()->bar(), etc etc) which throw parse errors in PHP 4.
+// Setup.php and ObjectCache.php have structures invalid in PHP 5.0 and 5.1, respectively.
+if ( !function_exists( 'version_compare' ) || version_compare( phpversion(), '5.2.3' ) < 0 ) {
+ $phpversion = htmlspecialchars( phpversion() );
+ $errorMsg = <<<ENDL
+ <p>
+ MediaWiki requires PHP 5.2.3 or higher. You are running PHP $phpversion.
+ </p>
+ <p>
+ Please consider <a href="http://www.php.net/downloads.php">upgrading your copy of PHP</a>.
+ PHP versions less than 5.3.0 are no longer supported by the PHP Group and will not receive
+ security or bugfix updates.
+ </p>
+ <p>
+ If for some reason you are unable to upgrade your PHP version, you will need to
+ <a href="http://www.mediawiki.org/wiki/Download">download</a> an older version
+ of MediaWiki from our website. See our
+ <a href="http://www.mediawiki.org/wiki/Compatibility#PHP">compatibility page</a>
+ for details of which versions are compatible with prior versions of PHP.
+ </p>
+ENDL;
+ wfDie( $errorMsg );
+}
+