#### 10.2.1 Testing the Test Suite

The best strategy for testing the CSSC test suite itself is to run it against a genuine edition of SCCS, if you have one available. Before running `make check`, set the environment variable ‘`dir`’ to point to the directory containing the programs to be tested; this should usually be `/usr/sccs`.

In many implementations of SCCS, some of the tools execute others (for example, `delta` often executes `get` to retrieve the previous version of the controlled file). This means that to correctly test the test suite, your `PATH` environment variable should be set up to select the SCCS tools you want to test. Here is an example of the correct way to set up the environment to test SCCS tools in `/usr/ccs/bin` :-

    dir=/usr/ccs/bin
    PATH=/usr/ccs/bin:$PATH
    export dir
    make check

When you are sure that the test script is expecting the correct behaviour from programs under test, you can then run it against CSSC. After all, if you’re going to set out writing your test by assuming that CSSC is correct in the area under test, of what value is the test?