Peter Eisentraut <peter.eisentraut@2ndquadrant.com> writes:
> I think one problem is that diff -u is not as portable as diff -c. For
> example, the HP-UX 11 man page of diff doesn't list it.
FWIW, I can confirm that HPUX 10.20's diff hasn't got it. That would
not affect gaur/pademelon, if we make this change, because I installed
GNU diffutils on that machine a decade or two ago. It might be a bigger
issue for the other HPUX critters though.
Some other data points:
* POSIX 2008 requires diff -u.
* SUS v2 (POSIX 1997) does not.
* My other pet dinosaur, prairiedog (macOS 10.4 something), has it.
regards, tom lane
