php操作大文件数据的方法

 1 @ini_set('memory_limit', '1G');

 2 $fp = fopen('E:/code/share/log.txt', 'r');

 3 if(fseek ($fp, 0, SEEK_END)!==-1){

 4     $maxPos = ftell($fp); 

 5     $last = 0;

 6     for($i=1; $i<$maxPos; $i++){

 7         fseek ($fp, $maxPos - $i, SEEK_SET);

 8         $data = fgets($fp);

 9         $cur = strlen(trim($data));

10         if($last > 0 && $last > $cur){

11             echo  $lastdata."----".$i."\n";

12         }

13         else{

14             $lastdata = $data;

15         }

16         $last = $cur;

17         if($i>50000) exit;

18     }

19 }

20 

21 fclose($fp);

22 exit("\n");