UPDATE: Reusing such URLs does not make any sense, so ignore this posting :(

I think the easiest solution is just to generate a list with all possible strings - at least for the short ones. Advantages are that you can block strings easily for n days (just add another col in your list or database) and that you always generate the shortest possible string (sort list by string length and availability). If strings should not be reused, then almut's solution is the best. 

#!/usr/bin/perl

use strict;
use warnings;

my @alphabet = ((1..9) , qw(a b c));

sub enum_words {
    my ($word, $maxlength) = @_;
    if (length $word < $maxlength) {
        for my $char (@alphabet) {
            enum_words($word . $char, $maxlength);
        }
    }
    else {
        print "$word\n";
    }
}

for my $length (1 .. 4) {
    enum_words('', $length);
}

[download]

In reply to Re: Long url to tiny url. by lima1
in thread Long url to tiny url. by valavanp

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.