A different approach - here's my generic solution to find out who is the winner of the tic-tac-toe. The basic idea is to list out the winning patterns, and then automatically generate regular expressions based on these patterns. This solution assumes that there is only one winner in the game.

#!/usr/local/bin/perl -w
use strict;
use re 'eval';

# A list of all winning patterns, could generate them
# with some sort of algorithm, but it's easier just
# to type them out.  ;-)

my @win = qw/
                XXX......
                X..X..X..
                ......XXX
                ..X..X..X
                ...XXX...
                .X..X..X.
                X...X...X
                ..X.X.X..
            /;

foreach (@win)  # dynamically generate regular expressions
{               # to look for matching winning patterns
    my $c = 0;
    s/X/!$c++?'([^-])':'(??{$1})'/ge;
}

while (my $game = <DATA>)
{
    my $winner = 'No body';
    foreach (@win) {
        $winner = $1, last if $game =~ /$_/;
    }
    print "$winner wins\n";
}

__DATA__
XO-OX--OX
OX-XO--XO
OOXOXOXOO
OX-XOOXOX
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And the output is -

X wins
O wins
X wins
No body wins
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