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 http://check.sourceforge.net/ for more information, including a
tutorial.

If you get Check out of CVS, you will need a working setup of automake
(at least version 1.4) and autoconf (at least version 2.13) in order
to successfully build Check. There's a script called autogen.sh that
calls autoconf and automake for you and then runs the generated 
configure script.