Waiting for asynchronous calls in a swift script

In addition to using dispatch_groups, you can also do the following:

yourAsyncTask(completion: {
    exit(0)
})

RunLoop.main.run()

Some resources:

• RunLoop docs
• Example from the swift-sh project
• Exit code meanings

Thanks to Aaron Brager, who linked to Multiple workers in Swift Command Line Tool ,

which is what I used to find my answer, using dispatch_groups to solve the problem.