--- cron.php	2005-03-20 11:03:12.000000000 +0100
+++ runcron.php	2005-03-20 11:03:16.000000000 +0100
@@ -3,6 +3,18 @@
 /**
  * @file
  * Handles incoming requests to fire off regularly-scheduled tasks (cron jobs).
+ * Recognizes the parameters 'include' and 'exclude' with a comma separated list of module names
+ * 
+ * Examples:
+ *  
+ * runs all hooks
+ * http://mysite.com/cron.php
+ * 
+ * runs all hooks except the search and aggregator modules
+ * http://mysite.com/cron.php?exclude=search,aggregator
+ * 
+ * runs only search, archive and aggregator modules
+ * http://mysite.com/cron.php?includ=search,archive,aggregator
  */
 
 include_once 'includes/bootstrap.inc';
@@ -15,24 +27,37 @@
 
 // Check if the last cron run completed
 if (variable_get('cron_busy', false)) {
-  watchdog('cron', t('Last cron run did not complete.'));
+  watchdog('cron', t('Last cron run did not complete.'), WATCHDOG_WARNING);
 }
 else {
   variable_set('cron_busy', true);
 }
 
-$modules = explode(',', $_GET['modules']);
-print_r($modules);
-exit();
-foreach ($modules as $module) {
-	module_invoke($module, 'cron');
+// initialize $modules
+$modules = array();
+
+// handle a list of modules to exclude
+if ($_GET['exclude']) {
+  $modules = module_list();
+  $exclude = explode(',', $_GET['exclude']);
+  $modules = array_diff($modules, $exclude);
+}
+// handle a list of modules to include
+else if ($_GET['include']) {
+  $modules = explode(',', $_GET['include']);
+} 
+// in the absence of excludes or includes run all
+else {
+  $modules = module_list();
 }
 
-// Iterate through the modules calling their cron handlers (if any):
-module_invoke_all('cron');
+// invoke cron for each of the modules in $modules
+foreach ($modules as $key => $module) {
+	module_invoke($module, 'cron');
+}
 
 // Clean up
 variable_set('cron_busy', false);
-watchdog('cron', t('Cron run completed'));
+watchdog('cron', t('Cron run completed. Modules included: '). implode(', ', $modules));
 
 ?>