php 处理大文件方法 SplFileObject

1     $csv_file = 'tmp.csv';
2     $start = isset($_GET['start']) ?intval($_GET['start']) : 1;       // 从第几行开始读取
3     $num = 100;             // 读取100行
4     $data = array();
5     $spl_object = new SplFileObject($csv_file, 'rb');
6     $spl_object->seek($start);
7     while ($num-- && !$spl_object->eof()) {
8         $data[] = $spl_object->fgetcsv();
9         $spl_object->next();
10     }