* character can be used as a wildcard to match sequences of unknown characters in the command line.
For example, lets say my elixir project has a few tests that I want to run in a directory:
MyProject/tests. The folder is filled with a bunch of random files, but the ones that i want to run have a similar name,
tests/user_views_show. We could use a wild card to match on both of these file names and run the tests (assuming there are no other files that match) like this:
mix test MyProject/tests/user_views*