Debian: Find out CPU usage using bash

Question

I'm using PHP to read the current CPU usage. I'm on a vServer, so shell_exec is enabled.

I have tried grep on ps, but it didn't work. How can I read the current % CPU usage using bash?

would load average from bash suffice? `cat /proc/loadavg` also, http://www.cyberciti.biz/tips/how-do-i-find-out-linux-cpu-utilization.html (sysstat) may be something you might want to use/install. — TryTryAgain, Mar 23 '12 at 16:08

score 5 · Accepted Answer · edited May 23 '17 at 11:56

5

The easiest way is simply to use sys_getloadavg

If you want to directly ask the OS, use uptime

$uptimeString = `uptime`;

Or any of the existing answers to how to do exactly the same thing in bash and just wrap in backticks.

edited May 23 '17 at 11:56

Community

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answered Mar 23 '12 at 16:06

AD7six

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I've seen the getLoadAvg commande before, but it's not the same as CPU usage (%). Both uptime and getloadavg could be interesting, too. But how can I find out the CPU usage? – bytecode77 Mar 23 '12 at 17:29
have you read the existing answers - e.g. the first answer in the question I linked to? – AD7six Mar 23 '12 at 18:16
Oh wait a moment. It always shows the same values, except if I wait for a few seconds. My PHP script always reads the same values... – bytecode77 Mar 23 '12 at 18:56

score 3 · Answer 2 · answered Mar 23 '12 at 20:38

After taking a closer look at all solutions, I came up with this code:

<?php
    exec('ps -aux', $processes);
    foreach($processes as $process)
    {
        $cols = split(' ', ereg_replace(' +', ' ', $process));
        if (strpos($cols[2], '.') > -1)
        {
            $cpuUsage += floatval($cols[2]);
        }
    }
    print($cpuUsage);
?>

It calls ps -aux and sums up the CPU %.

Debian: Find out CPU usage using bash

2 Answers2

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