Trigger a rule using a webform

In Drupal 7, to trigger a Rule using a Webform, create a webform with a markform component, perhaps named help, with the instructions for what submitting this form does.

Ex.

Click Refresh to refresh the data on this screen.

Change the submit button label to Refresh.

In addition to the help markup component, you must add a field to be submitted. Webforms that only have text components will not be submitted. This makes testing your rule very annoying.

Add a hidden component, perhaps named Dummy with default value "Refreshing..."

Make this type Hidden element.

That should do it for what you need to make your webform actually submit to trigger your rule.

Use the Webform Rules module to add a rule based on a webform being submitted.

Use Rules Exec to add an rules action to execute a shell command. If that's what you're after.