4.10. Use Mac OS X Automator to Delete Old Downloads

Mac OS X has a graphical way of writing batch files called Automator. In many ways, it is a graphical version of Monad even though it predates Monad by several years. To create Automator workflows (Mac OS X’s version of a script), drag commands from Automator’s work area and “wire” together the output of one command and the input of another. Each application registers its capabilities with Automator upon installation. You can also write pieces of Automator in ObjectiveC (the underlying development language of Mac OS X) to extend it.

Here is an example Automator workflow that deletes all the old files you’ve downloaded if they are more than two weeks old. The workflow is shown in Figure 4-3 and consists of the following steps:

Figure 4-3. “Delete old downloads” workflow in Mac OS X Automator

This workflow does more work than the Monad script above because there is no easy way in the workflow to specify that you want all the files not modified in the last two weeks. The best solution is to grab the ones that have been modified in the last two weeks, move them out of the way to a cache directory (named recent), and delete all the files in downloads. You would never bother to do this by hand, but because it’s an automated utility, it can do extra work. One alternative would be to write a shell script in bash and incorporate it into the workflow (one of the options is to call a bash script), but then you’re back to parsing out the results of a shell script to harvest the names. If you wanted to go that far, you could do the whole thing as a shell script.