php获取机器运行的时间， 获取文本的内容

function get_dev_run_time() 
{
    system("uptime > /var/uptime");
    $file = fopen('/var/uptime', 'r');
    if ($file) {
        $buffer = fgets($file, 1024);
        $str = explode(',', $buffer);

        $str1 = strstr($str[0], "day", true);
        if ($str1 != false) {
            $str2 = strstr($str1, "up", false);
            $days = substr($str2, 2);
            
            $str3 = strstr($str[1], "min", true);
            if ($str3 != false) {
                $hours = 0;
                $mins = $str3;
            } else {
                $str4 = explode(':', $str[1]);
                $hours = $str4[0];
                $mins = $str4[1];
            }
        } else {
            $days = 0;
            $str2 = strstr($str[0], "min", true);
            if ($str2 != false) {
                $hours = 0;
                $str3 = strstr($str2, "up", false);
                $mins = substr($str3, 2);
            } else {
                $str3 = strstr($str[0], "up", false);
                $time = substr($str3, 2);
                $str4 = explode(':', $time);
                $hours = $str4[0];
                $mins = $str4[1];
            }
        }
        
        fclose($file);
    }
    
    $format_time = $days."天".$hours."小时".$mins."分钟";
    
    return $format_time;
}