limits.h

[Moderator, John Quarterman]

Date: Fri, 15 Nov 85 00:48:36 cst
From: allegra!jpl (John P. Linderman)

I agree that values like OPEN_MAX that may well vary among binary
compatible machines should be determinable at execution time.  It
makes a lot of sense to have a routine that would look them up in
the copy of limits.h on the runtime machine.  If the file were
missing (or otherwise unusable), default values could be compiled
in from the copy of limits.h on the compile-time machine.  This
would leave us with sensible defaults, even on a bare-bones machine,
and a high level of compatibility across binary compatible machines,
regardless of the machine a source was compiled on.

I don't imagine people will bury these lookups deep in nested loops,
so efficiency shouldn't be much of an issue.  A lookup that invoked
cpp would be easy to write and would guarantee compatibility with
compile-time lookups.

John P. Linderman  allegra!jpl

Volume-Number: Volume 3, Number 20