#! perl -slw
use strict;

sub checkDiags {
    my $text = shift;
    my $x1 = 1 + index $text, "\n" or die 'Bad input';
    my $x2 = $x1-2;
    my $reMajor = qr[ ([12]) (?: .{$x1}\1 ){3} ]sx;
    my $reMinor = qr[ ([12]) (?: .{$x2}\1 ){3} ]sx;
    return $text =~ $reMajor || $text =~ $reMinor;
}


my $test = do{ local $/; <> };
print "$test\n", checkDiags( $test ) ? 'Matched' : 'Failed';

__END__
c:\test>junk40
0100000000
0010000000
0001000000
0000100000
0000000000
^Z
0100000000
0010000000
0001000000
0000100000
0000000000

Matched

c:\test>junk40
0000000
0000020
0000200
0002000
0020000
0000000
^Z
0000000
0000020
0000200
0002000
0020000
0000000

Matched
[download]

Thanks BrowserUk, this is what i expect. :)