A brief analysis of the method of forcing downloading of files in PHP

$filename = "test.txt";
header ("Content-Type: application/force-download");
header ('Content-Disposition: attachment;filename="'. $filename.'"');
readfile ($filename);

This way, the file can be downloaded directly instead of opened.

Principle analysis: 1. header ("Content-Type: application/force-download"); //Force download; 2. header ('Content-Disposition: attachment; filename="'.$filename.'"'); //Implement file download. Finally, readfile($filename) reads the file for download.