blackbox testing of Unix command line programs

 cmdtest black box tests Unix command line tools. Roughly, it is given a
 a script, its input files, and its expected output files. cmdtest runs
 the script, and checks the output is as expected.
 .
 cmdtest is aimed specifically at testing non-interactive Unix command
 line programs, and tries to make that as easy as possible.
 .
 Also included is a "scenario testing" tool, yarn.