Question

I’ve attempted to write a PHP class that gets the uptime of my Linux machine. It will get the uptime correctly, but I have an if statement that determines whether or not the load average is “high” or not and set a warning code, and it doesn’t seem to be working (it stays at 0).

I’ve included all of the code here from the class (50 or so lines) because I didn’t know what I could take out but still provide some info about what’s going wrong here.

<?php
class loadavg {

    private $divisor, $status;

    public function __construct($set_divisor = 1){
        $this->divisor = $set_divisor;
    }

    public function __toString(){
        return $this->load(1).', '.$this->load(5).', '.$this->load(15)."\n";
    }

    public function load($time = 1){
        $loadfile = shell_exec('cat /proc/loadavg');
        $split = preg_split('/ /', $loadfile);

        if ($split[1] > (2 * $this->divisor)){
            $this->status = 3;
        } else if ($split[1] > $this->divisor){
            $this->status = 2;
        } else {
            $this->status = 1;
        }

        switch($time){
            case 1:
                return $split[0];
            case 5:
                return $split[1];
            case 15:
            return $split[2];
        }
    }

    public function status_name(){
        switch ($this->status){
            case 3:
                return 'critical';
            case 2:
                return 'warn';
            case 1:
                return 'ok';
            case 0:
                return 'error';
        }
    }
}
?>

Answer 1

<?
class loadavg {

    private $divisor, $status;

    public function __construct($set_divisor = 1){
        $this->divisor = $set_divisor;
    }

    public function __toString(){
        return $this->load(1).', '.$this->load(5).', '.$this->load(15)."\n";
    }

    public function load($time = 1){
        //$loadfile = shell_exec('cat /proc/loadavg');
        $loadfile = '1.5 1.5 1.5';
        $split = preg_split('/ /', $loadfile);

        if ($split[1] > (2 * $this->divisor)){
            $this->status = 3;
        } else if ($split[1] > $this->divisor){
            $this->status = 2;
        } else {
            $this->status = 1;
        }

        switch($time){
            case 1:
                return $split[0];
            case 5:
                return $split[1];
            case 15:
            return $split[2];
        }
    }

    public function status_name(){
        switch ($this->status){
            case 3:
                return 'critical';
            case 2:
                return 'warn';
            case 1:
                return 'ok';
            case 0:
                return 'error';
        }
    }
}

$la = new loadavg();
print($la);
print($la->status_name()); 

I just executed this, and got the output:

1.5, 1.5, 1.5
warn

Isn’t this what is expected? If I take out the print($la) statement, the output is this:

error

this is because the load() function is never called to set the status. If you want to have the status printed out correctly, you have to run load() first. I assume you’d want to add the time parameter to status_name and call load before returning, like this:

public function status_name($time =1){
    $this->load($time);
    switch ($this->status){
        case 3:
            return 'critical';
        case 2:
            return 'warn';
        case 1:
            return 'ok';
        case 0:
            return 'error';
    }
}

which will now enable you to do this:

$la = new loadavg();
print($la->status_name(5));