!!!!??? The manual gives an example of a simple backup of "your site every 24 hours" with the following getCache call [[!getCache? &element=`backup` &excludeTables=`my_custom_table,my_other_custom_table` &cacheExpires=`86400` ]]
This question has been answered by treigh. See the first response.
/usr/bin/curl -o /Path/to/Home_Directory/Backup_Folder/cron_result.txt http://yourdomain.com/assets/components/cronmanager/cron.php
curl: no URL specified!
I wonder if that's a typo in the docs. Try databackup.purge instead.
Quote from: BobRay at Sep 06, 2013, 06:38 PMI wonder if that's a typo in the docs. Try databackup.purge instead.
no, it's not a typo—that's the correct name for the property :/

$settings['databackup.purge']= $modx->newObject('modSystemSetting');
$settings['databackup.purge']->fromArray(array (
'key' => 'databackup.purge',
'value' => '1814400',
'xtype' => 'textfield',
'namespace' => 'databackup',
'area' => 'File System',
), '', true, true);if (empty($purge)) $purge = $modx->getOption('databackup.purge', null, 1814400);