### 10.2 Writing new test cases

The test cases are really just shell scripts. They are suitable for `/bin/sh` on most machines. The procedure for running these is explained in Running the tests. These shell scripts read in some common function definitions (mostly from `tests/common/test-common`) and then proceed to conduct the tests. This section explains those commands used in the test scripts that are not simply normal shell commands. Normal shell commands like `sed` and `grep` are not described.

The best approach for writing new test scripts or just individual new test cases is to first think of some aspect that needs better test coverage, and then to write the test script, basing it on an existing script. To make sure that your new tests are really checking for the right things, you can run them against an existing SCCS implementation other than CSSC.