#!/usr/bin/perl
use warnings;
print "Enter no of days older : \n";
$days = <STDIN>;
chomp $days;

if ($days = ~ /^\s*[1-9][0-9]*\s*$/)
{
print "Inside if : $days \n\n";
}
else
{
print "Inside else \n\n";
}

##</code><code>##

Use of uninitialized value in pattern match (m//) at ./tt.pl line 8, <STDIN> line 1.