Knock is a simplification of the Test Anything Protocol used by Perl and others.
Every test suite is a script that prints lines looking like:
  ok ...        for a passed test
  not ok ...    for a failed test
  # ...         for diagnostics
Everything else is ignored.  Scripts should exit with 0 when they ran
all tests and non-0 when there was a fatal error.
Included implementations:
  knock.h       (GNU/C99) macros for Knock in C
  knock.rb      Knock for Ruby
  knock.sh      Knock for sh and bash
  knock.zsh     Knock for zsh
Tools included are:
  kn-sum        print a summary of the Knock input given on stdin
  kn-agg        print a summary of the Knock input, as Knock line
  kn-nice       reformat Knock to make it easier scannable
For usage, see the test suite "test-all" in test/.
Why "Knock"?  Think "knock on wood... tap tap".  (Thanks to Eric
Hollensbe for the name idea.)
--Christian Neukirchen, 17aug2008