Testing C Code. Is there a Test Method for me?

I am writing a program in C that recursively forks and sorts .csv files in a directory and all its subdirectories. We will be forking a process each for all files and all subdirectories. In the end a list of PIDs will be printed. Is there a program/library or a Unit test that will help me test my program? I want to get into TDD as a learning student.