如何在PHP中获取系统命令执行的响应状态值

Question

I want to know the response status of system command execution in PHP, I tried this below code , but it always returns 0 value ,Here is my code:

<?php
system("ls -lrt ",$return_value);
echo $return_value;
?>

Answer 1

In bash，it uses 0 to express everything is ok. The command 'ls -lrt' will not fail, so it return 0. If you want to get output, you should use exec()