An alternative to tranliterating to delete the \0 characters and then getting the length of what's left would be to complement the \0's, assigning to a scalar so as to count all non-nulls.

    my $count = $x =~ tr/\0//c;
    print "'$s' at offset $i matched" unless $count > 1;
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It's six of one, a half-dozen of the other I suppose but I thought it might be worth a mention.