This is a difficult problem in Perl for the most general case. Numbers like 1111111111111111111e1111111111111111111 pass the 'looks_like_number' test but don't fare well in arithmetic expressions. This doesn't do what you would hope: 
use strict;
use warnings;
use Scalar::Util qw(looks_like_number);

my $c="11111111111111111e11111111111111111";
my $d="22222222222222222e22222222222222222";

if (looks_like_number($c) and 
    looks_like_number($d) and 
    $c == $d) {
  print "$c = $d\n";
}

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It should work perfectly the first time! - toma

In reply to Re: Equality checking for strings AND numbers by toma
in thread Equality checking for strings AND numbers by Anonymous Monk

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