This time I have to tell you, you're wrong - sorry.

Really? I tested my solution, did you?

#!/usr/bin/perl

use strict;
use warnings;

my $str = "A'Bcd";

$_ = $str; s/(')/\Q$1$1/g; print "$_\n";
$_ = $str; s/'/\Q''/g; print "$_\n";
$_ = $str; s/(')/quotemeta "$1$1"/eg; print "$_\n";

__END__
A\'\'Bcd
A\'\'Bcd
A\'\'Bcd
[download]

Seems to print \'\' for every ' to me.

Abigail