Subject: bug#19533: comm does not detect common lines -- Mac OS X 10.9.5

From: Bob Proulx <[email-masked]>
Date: Thu, 8 Jan 2015 10:45:41 -0700

Ali Khanafer wrote:
> Thanks Eric and Bob. I had sorted the files before calling comm, but I
> think the problem is that I sorted them as numeric:
> 
> sort -n test1 -o test1
> 
> When I removed the "-n", which is equivalent to what Bob has done, comm
> worked like a charm.

Yes that would cause the problem.  comm is a simple program from years
and years ago and expects things to be sorted simply.  Sort options in
the various programs have come up for discussion every so often.  But
so far things have continued as they are.  The biggest changes in this
area have been having the tools produce diagnostic information when
the input is not as they expect.  Check out the sort --debug option
for more useful diagnostics about sorting.

Glad things have been /sorted/ out! :-)

Bob