To prevent cut and paste, how about asking them to enter the id (or email address or whatever) first forward and then in reverse. Then reverse the second entry before comparing them for equality using a subroutine; for example:

# assuming the strings are now stored in $forward and $backward...
Reverse( \$backward );
unless ( $forward eq $backward ) {
    # code to handle confirm error
}

#...

# pass the string by reference e.g. Reverse( \$backward );
sub Reverse {
    my $sref = shift;
    my $reversed = '';
    for ( my $idx = length( $$sref ) - 1; $idx >= 0; $idx-- ) {
        $reversed .= substr( $$sref, $idx, 1 );
    }
    $$sref = $reversed;
}

[download]

One world, one people

In reply to Re: prevent pasting into a CGI textbox by anonymized user 468275
in thread prevent pasting into a CGI textbox by nosbod

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.