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Re: something like perl's 'require 5.4'
Craig Markwardt wrote:
> Vapuser <email@example.com> writes:
> > Hi all.
> > I'm looking for something that check the version of the current IDL
> > session against an input version, like perl's 'require 5.4'
> > semantics and I *thought* I saw someone mention using something very
> > much like this.
> > Does anyone know of such a thing or was I just hallucinating?
> Extending on JD's answer with two more possibilities:
> if !version.release LT '5.4' then message, 'ERROR'
> if double(!version.release) LT 5.4 then message, 'ERROR'
> The first comparison is a string compare, while the second one is a
> numeric compare. There is a slight difference, but in practice they
> are identical, and they also both handle the case of 5.4.1, etc. The
> former will handle 5.4.1a, but I think it's rare. I always use the
IDL> print,double('5.4') lt double ('5.4.1')
IDL>print,double('5.4') eq double ('5.4.1')
Hopefully RSI won't try to pull the latter on us.
On the other hand, your string method looks good. The best counter
example I could come up with is:
IDL> print,'5.5a' lt '5.5B'
Not too likely. I think I'll adopt the string version.