cmdtest black box tests Unix command line tools.
Roughly, it is given a command line and input files, and the expected output,
and it verifies that the command line produces the expected output.
If not, it reports a problem, and shows the differences.
See also:
- Using stuff on code.liw.fi
- Tarball and Debian packages: http://code.liw.fi/debian/pool/main/c/cmdtest/