Check for Positive Integer entry

positive_int.pl

#!/usr/bin/perl
use B;
use Scalar::Util::LooksLikeNumber 'looks_like_number';

sub positive_int {
    my $lln = looks_like_number($_[0]);
    ($lln == 1 || $lln & B::SVf_IOK) && $_[0] > 0;
}
for (0, "0", 123, "123", 123.45, "123.45", "yolki-palki", "nancy") {
    print "$_ -> " . (positive_int($_) ? "true" : "false");
}

#0 -> false
#"0" -> false
#123 -> true
#"123" -> true
#123.45 -> false
#"123.45" -> false
#"yolki-palki" -> false
#"nancy" -> false