Field1,Field2,Field3 1.00,Blue,12:00 <----- 40.20,White,12:00 80.30,White,12:00 120.00,White,12:00 126.00,White,12:00 <----- 162.43,White,12:00 <----- 198.86,White,12:00 <----- 235.29,White,12:00 <----- 271.72,Red,03:45 <===== 308.15,White,12:00 <----- 344.58,White,12:00 <----- 381.01,White,12:00 <----- 417.44,White,12:00 <----- 453.87,White,12:00 490.30,White,12:00 526.73,White,12:00 563.16,Red,07:45 599.59,White,12:00 636.02,White,12:00 672.45,White,12:00 708.88,White,12:00 745.31,White,12:00 781.74,White,12:00 818.17,White,12:00 854.60,Blue,12:00 <----- 891.03,White,12:00 963.89,White,12:00 1000.32,White,12:00 1036.75,Red,08:30 1073.18,White,12:00 1109.61,Red,06:00 1146.04,White,12:00 1182.47,White,12:00 1218.90,White,12:00 18516.40,Blue,12:00 1255.33,White,12:00 927.46,White,12:00 ##

##

1.00,Blue,12:00
126.00,White,12:00
162.43,White,12:00
198.86,White,12:00
235.29,White,12:00
271.72,Red,03:45
308.15,White,12:00
344.58,White,12:00
381.01,White,12:00
417.44,White,12:00
854.60,Blue,12:00

##

##

my @res = analyze();
for (@res) {
    print $_->{f1} . ',' . $_->{f2} . ',' . $_->{f3} . "\n";
}

sub analyze {
    
    # get the data as an array of hashes just like DBI would return
    my @data = map { 
        chomp; 
        split /,/; 
        { f1 => $_[0], f2 => $_[1], f3 => $_[2] } 
    } ;
    
    # arrays for holding bits of results
    my (@res_red, @res_blu, @res_wht, 
        @nxt_res_red, @nxt_res_blu, @nxt_res_wht
     );
    
    # counters for tracking whether we are before or 
    # after the 'Red' divide 
    my $i = -1; my $j;
    
    # array to hold rows *before* the 'Red' divide
    my @seen;
    
    LOOP: for (@data) {
        if ($i >= 0) {

            if ($_->{f2} eq 'White') {
                next LOOP if $j > 3;
                push @nxt_res_wht, $_;
                $j++;
            }
            
            if ($_->{f2} eq 'Blue') {
                push @nxt_res_wht, $_;
                last LOOP;
            }
        }
        else {
            if ($_->{f2} eq 'Red') {
                push @res_red, $_;
                $i++;
                my @rev_seen = reverse @seen;
                my $k;
                REV_WHITE: for (@rev_seen) {
                    if ($_->{f2} eq 'White') {
                        push @res_wht, $_;
                        $k++
                    }
                    last REV_WHITE if $k > 3;
                }
                REV_BLUE: for (@rev_seen) {
                    if ($_->{f2} eq 'Blue') {
                        push @res_blu, $_;
                        last REV_BLUE;
                    }
                }
                push @res_blu, reverse(@res_wht), @res_red;
            }
            else {
                push @seen, $_;
            }
        }
    }
    push @res_blu, @nxt_res_wht, @nxt_res_red;
    return @res_blu;
}


__DATA__
1.00,Blue,12:00
40.20,White,12:00
80.30,White,12:00
120.00,White,12:00
126.00,White,12:00
162.43,White,12:00
198.86,White,12:00
235.29,White,12:00
271.72,Red,03:45
308.15,White,12:00
344.58,White,12:00
381.01,White,12:00
417.44,White,12:00
453.87,White,12:00
490.30,White,12:00
526.73,White,12:00
563.16,Red,07:45
599.59,White,12:00
636.02,White,12:00
672.45,White,12:00
708.88,White,12:00
745.31,White,12:00
781.74,White,12:00
818.17,White,12:00
854.60,Blue,12:00
891.03,White,12:00
963.89,White,12:00
1000.32,White,12:00
1036.75,Red,08:30
1073.18,White,12:00
1109.61,Red,06:00
1146.04,White,12:00
1182.47,White,12:00
1218.90,White,12:00
18516.40,Blue,12:00
1255.33,White,12:00
927.46,White,12:00