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Re: something like perl's 'require 5.4'

Vapuser <vapuser@catspaw.jpl.nasa.gov> 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


Craig B. Markwardt, Ph.D.         EMAIL:    craigmnet@cow.physics.wisc.edu
Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response