I came across the "--delete-after" option when I was reading the manpage of wget ? what's the purpose of providing such an option ? Is it just for testing the page is ok for downloading ? Or maybe there are other situations where this option is useful, I hope you guys may give me some hints.
With reference to your comments above. I'm providing some examples of how we use it. We have a few websites running on Rackspace Cloud Sites which is a managed cloud hosting solution. We don't have access to regular cron.
We had an issue with runaway usage on a site using WordPress because WP kept calling wp-cron.php. To give you a sense of runaway usage, it used up in one day the allotted CPU cycles for a month. Anyway what I did was disable wp-cron.php being called within the WordPress system and manually call it through wget. I'm not interested in the output from the process so if I don't use --delete-after with wget (wget ... > /dev/null 2>&1 works well too) the folder where wget runs would get filled with hundreds of useless logs and output of each time the script was called.
We also have SugarCRM installed and that system requires its cron script to be called to handle system maintenance. We use wget silently for that as well. Basically a lot of these kinds of web-based systems have cron scripts. If you can't call your scripts directly say using php on the machine then the other option is calling it silently with wget.
The command to call these cron scripts is quite basic - wget --delete-after http://example.com/cron.php?parameters=if+needed