use the in-built version_compare functionality to check php version is valid.

mantis · mantis · commit 3854c4d1f1ca · 2013-04-05T20:23:15.000+01:00
diff --git a/core.php b/core.php
@@ -280,7 +280,7 @@ function __autoload( $p_class ) {
 require_api( 'php_api.php' );
 
 # Enforce our minimum PHP requirements
-if( !php_version_at_least( PHP_MIN_VERSION ) ) {
+if( !(version_compare(PHP_VERSION, PHP_MIN_VERSION ) >= 0 ) ) {
 	@ob_end_clean();
 	echo '<strong>FATAL ERROR: Your version of PHP is too old. MantisBT requires PHP version ' . PHP_MIN_VERSION . ' or newer</strong><br />Your version of PHP is version ' . phpversion();
 	die();
diff --git a/core/php_api.php b/core/php_api.php
@@ -52,37 +52,3 @@ function php_mode() {
 
 	return $s_mode;
 }
-
-/**
- * Returns true if the current PHP version is higher than the one specified in the given string
- * @param string $p_version_string php version string to check
- * @return bool
- */
-function php_version_at_least( $p_version_string ) {
-	static $s_cached_version;
-
-	if( isset( $s_cached_version[$p_version_string] ) ) {
-		return $s_cached_version[$p_version_string];
-	}
-
-	$t_curver = array_pad( explode( '.', phpversion() ), 3, 0 );
-	$t_minver = array_pad( explode( '.', $p_version_string ), 3, 0 );
-
-	for( $i = 0;$i < 3;$i = $i + 1 ) {
-		$t_cur = (int) $t_curver[$i];
-		$t_min = (int) $t_minver[$i];
-
-		if( $t_cur < $t_min ) {
-			$s_cached_version[$p_version_string] = false;
-			return false;
-		}
-		else if( $t_cur > $t_min ) {
-			$s_cached_version[$p_version_string] = true;
-			return true;
-		}
-	}
-
-	# if we get here, the versions must match exactly so:
-	$s_cached_version[$p_version_string] = true;
-	return true;
-}
