Replace all "don't care characters" with . and you have a regex that does the job. 

use strict;
use warnings;
my $abc = "AABCBAABCCCCAB";
my $ab  = "AABABAABABABAB";
$abc =~ s/[^ab]/./gi;
print "They match!\n" if $ab =~ /^$abc$/i;

[download]

If you want to use logical operators the following works as well 

print "They match!\n" unless ($abc ^ $ab) =~ /\x{3}/;

[download]

In reply to Re: Tri state string compare? by hdb
in thread Tri state string compare? (Solved! see update2) by BrowserUk

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