SlackBuilds.org/development/check

Check is a unit test framework for C. It features a simple interface for
defining unit tests, putting little in the way of the developer. Tests are
run in a separate address space, so Check can catch both assertion failures
and code errors that cause segmentation faults or other signals. The output
from unit tests can be used within source code editors and IDEs.

See the project's home page for more information, including a tutorial.