raspap-webgui/app/lib/system.php

<?php

class System {
  public function hostname() {
    return shell_exec("hostname -f");
  }

  public function uptime() {
    $uparray = explode(" ", exec("cat /proc/uptime"));
    $seconds = round($uparray[0], 0);
    $minutes = $seconds / 60;
    $hours   = $minutes / 60;
    $days    = floor($hours / 24);
    $hours   = floor($hours   - ($days * 24));
    $minutes = floor($minutes - ($days * 24 * 60) - ($hours * 60));
    $uptime= '';
    if ($days    != 0) {
        $uptime .= $days    . ' day'    . (($days    > 1)? 's ':' ');
    }
    if ($hours   != 0) {
        $uptime .= $hours   . ' hour'   . (($hours   > 1)? 's ':' ');
    }
    if ($minutes != 0) {
        $uptime .= $minutes . ' minute' . (($minutes > 1)? 's ':' ');
    }

    return $uptime;
  }

  public function usedMemory() {
    $used = shell_exec("free -m | awk '/Mem:/ { total=$2 ; used=$3 } END { print used/total*100}'");
    return floor($used);
  }

  public function processorCount() {
    $procs = shell_exec("nproc --all");
    return intval($proc);
  }

  public function loadAvg1Min() {
    $load = exec("awk '{print $1}' /proc/loadavg");
    return floatval($load);
  }

  public function systemLoadPercentage() {
    return intval(($this->loadAvg1Min() * 100) / $this->processorCount());
  }
}