php 怎么删除CSV文件里面的列

[User:root Time:05:47:12 Path:/home/liangdong/php]$ php csv.php [User:root Time:05:47:14 Path:/home/liangdong/php]$ cat csv.out aaa null111 222444 123123 456[User:root Time:05:47:17 Path:/home/liangdong/php]$ cat csv.php <?php $fin = fopen('csv.txt', 'r');$fout = fopen('csv.out', 'w');while (($row = fgetcsv($fin, 0, ' ', ' ', ' ')) !== false) {        $index = array_search(123, $row);        if ($index !== false) {                $filter[$index] = true;        }}fseek($fin, 0, SEEK_SET);while (($row = fgetcsv($fin, 0, ' ', ' ', ' ')) !== false) {        $out_row = array();        foreach ($row as $index => $value) {                if (isset($filter[$index])) {                        $out_row[] = $value;                }        }        if (!empty($out_row)) {                fputcsv($fout, $out_row, ' ', ' ');        }}fclose($fin);fclose($fout);?&gt;<div class="clear"></div>