Re: RFC: Port of NetBSD cat(1)'s -f option.

On Thu, May 16, 2002 at 02:14:05PM +0200, Dag-Erling Smorgrav wrote:
> Peter Pentchev <[email protected]> writes:
> > Also, aren't we supposed to test the return values of syscalls explicitly
> > against -1, and not just < 0?
> 
> Is a negative return value different from -1 more correct than -1?
> Should it be silently ignored?

Hmm.  The standards (and our manual pages) say that most syscalls
return *exactly* -1 on error.  A negative value different than -1
should be treated as some kind of meta-error; maybe something
that might warrant an err(EX_OSERR, ...).  No, I do not really
think that it is possible - or even thinkable - to make that check
every time a syscall is invoked :)

Actually, now I don't know what to think - for the past few months,
I have been writing my own programs with explicit checks for -1.
Is there an OS out there that returns negative values other than -1?
I presume that no *new* OS and no new syscalls will be written to
return such, so no further incompatibility would be introduced;
but is there an existing platform that would break programs which
check explicitly for -1?

G'luck,
Peter

-- 
Peter Pentchev	[email protected]	[email protected]
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What would this sentence be like if it weren't self-referential?

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