php处理文件进度条的实现方法

// Start the session. 
session_start(); 
// The example total processes. 
$total = 20; 
// The array for storing the progress. 
$arr_content = array(); 
// Loop through process 
for($i=1; $i<=$total; $i++){ 
  // Calculate the percentation 
  $percent = intval($i/$total * 100); 
  // Put the progress percentage and message to array. 
  $arr_content['percent'] = $percent; 
  $arr_content['message'] = $i . " row(s) processed."; 
  // Write the progress into file and serialize the PHP array into JSON format. 
  // The file name is the session id. 
  file_put_contents("tmp/" . session_id() . ".txt", json_encode($arr_content)); 
  // Sleep one second so we can see the delay 
  sleep(1); 
}