After you have built chu, you might wish to test it.  The file testsignal.gz
is supplied for this purpose.  This file is not an actual recording of CHU,
but rather a synthesized signal created for the purpose of testing this
software.  Thus it has perfect timing, that could not be reproduced with
a real sound card.

Unzip the testsignal file with:

    gzip -d testsignal.gz

Then run:

    chu -l:10 testsignal

The -l switch is used so you don't in-advertantly set your clock back to
December 25, 1993, which is the time encoded in the test signal.

It will print out lots of information, but the last few lines should look
like this:

Computing with 10 tone samples
offset = -28.137367
sound card error = 0.000 ppm
max_variance = 0.000002
mean_variance = 0.000000
WARNING: Adjustment exceeds maximum allowed: 161436151.862633

The value of offset, and number in the last line is dependant on when
you run the program.  The rest of these lines should match though.

The sound card error should be zero, as well as the mean variance.