Program : 

#!/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";
}

[download]
o/p :

Enter no of days older :
9
Use of uninitialized value in pattern match (m//) at ./tt.pl line 8, <
+STDIN> line 1.

[download]
Inside if : 18446744073709551615

I dont want my $days value to change after Inside if statement. And how can the warning of uninitialized value be reolved?
And is the regex apt for validating whether the entered input is a positive integer or not and also greater than zero?

In reply to Validation of UserInput is a positive Integer or not? by G Nagasri Varma

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.