you could use Scalar::Utils looks_like_number: 

use Scalar::Util qw(looks_like_number);

my $myval = someKindOfUserInput(); # jepp, I'm mostly into java here @
+work ,)
[...]

if (looks_like_number($myval)) {
   # a number, maybe even Inf or somesuch thing
}

[...]

[download]
Edit: "enhanced" the code-snippet, declaring the tested variable...

regards,
tomte

Hlade's Law:

If you have a difficult task, give it to a lazy person --
they will find an easier way to do it.

In reply to Re: How to check Inputs if Numeric by Tomte
in thread How to check Inputs if Numeric by kasmot

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