How to get list of cron tasks?

Question

Drupal 6 possible noob question. Is there a way to get a list of cron tasks from the Drupal 6 Admin? I am a themer for the site. The original dev is long gone. Everyone complains of slowness and 500.shtml errors. I looked in the log and noticed that these are most often associated with a cron task that runs hourly. But I can't see what those jobs are. Once I get the list is there also a way to disable unneeded tasks from within Drupal?

I'm running Windows on my client machine. I don't have DRUSH.

Thanks In Advance

Answer 1

If you don't have Elysia Cron installed, and from a purely debugging standpoint, if you want or need to see what module's cron is running, as well as how long it is taking to run, you can TEMPORARILY edit includes/common.inc's drupal_cron_run() function like so...

// Iterate through the modules calling their cron handlers (if any):
// module_invoke_all('cron'); // watchdog how long each hook takes now...

$details='';
foreach (module_implements('cron') as $module) {
  $start=microtime(TRUE);
  $function = $module . '_cron';
  $function();
  $finish=microtime(TRUE);
  $duration=$finish - $start;
  $details.='<pre>' . $module . ': ' . $duration . ' seconds</pre>';
}

// Record cron time
variable_set('cron_last', time());
watchdog('cron', 'Cron run completed.' . $details, array(), WATCHDOG_NOTICE); // . in $details here :)

eg, comment out the module_invoke_all() and instead loop through via module_implements() and log how long each individual cron run takes.

Answer 2

Or simple use

drush ev 'var_dump(module_implements("cron"))'

For list the cron job that exists.

Answer 3

For Drupal 8/9, you can simply use the following command:

drush php-eval 'var_dump(\Drupal::moduleHandler()->getImplementations("cron"))'