Then, you must test your program with this data, and explain the results. Your testing should be presented in such a way that the reader is convinced of your program's correctness. It is insufficient to simply show the results of executing your program on some arbitrary set of test data. If necessary, divide the testing into sections. For example, test the user interface, then the correctness of the algorithm, then the program's error handling ability.
Line numbers are essential when there are empty lines in the test data.
Line numbers can be generated using the -n option on the cat command and the output can be inserted into your testing documentation. Test Data and Output Program testing must be done in two steps. First, choose a set of test data to exercise all execution paths. You are also required to test your program as a solution to a class of situations. For example, if you are writing a sorting algorithm, you should also test how it handles trivial cases, ascending data, descending data, random data, large sets of data, etc.