Even if its a 'low volume' form you still may get 2 people hitting it at the same time even if you only get 3 hits on a given day.

One easy one if you aren't worried about people making these up to circumvent the reason you are using a random value in the first place would be to use pid and Time::HiRes; 

use strict;
use Time::HiRes qw(time);

my $uniq_value="$$" . time;

[download]

$uniq_value will be something like 153331000916182.10074

This will be unique since the same CGI can't do 2 of these without that last digit stepping with current CPU and network speeds and each process has its own pid so even 2 at the same time will be unique.

The number could be predicted in advance since its totally linear and not random at all.

In reply to Re: gernerating unique string by dga
in thread gernerating unique string by Anonymous Monk

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.