Regexp::Common might keep you from reinventing the wheel: 

use Regexp::Common;

while (<DATA>) {
    chomp;
    /^$RE{num}{real}$/ and print "$_ is a number\n";
}

__DATA__
123
abc
0.123

[download]

In reply to Re: Checking whether a value is numeric or not by almut
in thread Checking whether a value is numeric or not by rsriram

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