bug#7877: sleep takes undocumented hex args

[Jim Meyering]

Paul Eggert wrote:
> On 01/21/2011 01:24 AM, Jim Meyering wrote:
>> My first reflex was to make sleep reject args like 0x... and inf.
>
> My reflex was just the opposite: why reject a notation
> that might be useful?

I see that at least freebsd's /bin/sleep and the one from sunos 5.11
work just like the one from coreutils (without my proposed change)
in accepting e.g., 0x1 and inf.

netbsd's accepts 0x1 but not inf.
openbsd's accepts neither.

> Several other programs (printf, seq, sort, tail, plus many
> other GNU programs) also use strtod or strtold.  If 'sleep' is
> changed to reject hexadecimal and infinity, shouldn't they
> be changed too, for consistency?
>
> I expect it's better to leave these programs alone.  Not only
> is this simpler, and a tiny bit cheaper at runtime, it's slightly
> less likely to break existing usage.
>
> Anyway, whatever we do, we should document it better.  To start the ball
> rolling on that, I pushed the following change, which documents the
> existing behavior.  We can change this if we change the behavior.

The above, plus your added documentation are good enough
reasons to leave sleep as-is.

Thanks.