Calling Server Action From curl - How Do I Specify Username and Password?

I am creating a crontab to execute a GET server action which is protected by a username and password based security provider. The crontab will execute a curl to do this.

What curl syntax do I need for specifying the username and password?

curl http://test.workshop-angel.com/dmxConnect/api/crontab/crontab_test.php WHAT_OPTIONS_HERE?

If being called from another server action, I would be calling crontab_test.php like this: