[Nagiosplug-devel] Nagios::Plugin with scientific notation

Vonnahme, Nathan nathan.vonnahme at bannerhealth.com
Thu Mar 20 18:29:06 CET 2008

> On 13 Mar 2008, at 17:19, Vonnahme, Nathan wrote:
> > Larry Wall said in one of his State of the Onion speeches that it's
> > better for programs (and also community members) to be "generous in
> > what
> > you accept for input and strict in what you produce as output".
> That's a good principle. I guess that means anything parsing the perf
> data should cater for scientific notation, but the plugins should only
> return a certain format.

That sounds like too much work for a small set of cases.  I think it
would suffice for parsers to produce a polite error message when they
detect scientific notation (or anything else they can't handle).

> In which case, what is the precision? Can we say at the time of
> printing the value, it is something like:
> $value_as_text = sprintf("%.5f", $value);
> $value_as_text =~ s/0+$/; # Remove trailing zeros
> $value_as_text =~ s/\.$/; # Remove trailing separator
> Hmmm, different languages have different separators, so do we state
> that the value will come from the POSIX locale? (decimal point is a
> dot, no 'thousands' grouping).
> I'm thinking that the performance data doesn't need to be much more
> precise than this - Nagios plugin performance data is guidance, not
> exact.

That should be plenty of precision, but I'd suggest deferring
localization to somewhere closer to the user interface layer (in this
case, the web CGIs and the notification scripts).  

I doubt if any of the existing plugins produce localized output, and in
a way, producing differently punctuated output in different environments
is the opposite of being "strict".


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