Can anyone tell what this cronjob does?

Question

I am learning about cronjob and I found this piece of code in one project which fetches record from twitter,

the code goes like this:

#0 * * * * cp /vold/www/Abcd/log/twitter_feed_item_aggregator.log vold/www/Abcd/log/twitter_feed_item_aggregator.log.backup; > /vold/www/Abcd/log/twitter_feed_item_aggregator.log   

Can anyone explain what this piece of code does?

Answer 1

Hm... Copies a twitter agregator log each hour, and then clears it.

This part 0 * * * * means 'every 0 minutes'. Minute 0 is when a new hour starts.

This part cp /vold/www/Abcd/log/twitter_feed_item_aggregator.log vold/www/Abcd/log/twitter_feed_item_aggregator.log.backup obviously copies the log to a backup.

This part > /vold/www/Abcd/log/twitter_feed_item_aggregator.log outputs the output of no command to the file, thus clearing it.

Answer 2

The hash at the start of the line comments out the line so it does nothing. Without that it would do as @playcat says.