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");