Function to get current CPU load as percentage value under Windows and Linux.
Note: Function is getServerLoad(). It will return a decimal value as percentage of current CPU load or NULL if something went wrong (e. g. insufficient access rights).
<?php
header("Content-Type: text/plain");
function _getServerLoadLinuxData()
{
if (is_readable("/proc/stat"))
{
$stats = @file_get_contents("/proc/stat");
if ($stats !== false)
{
// Remove double spaces to make it easier to extract values with explode()
$stats = preg_replace("/[[:blank:]]+/", " ", $stats);
// Separate lines
$stats = str_replace(array("\r\n", "\n\r", "\r"), "\n", $stats);
$stats = explode("\n", $stats);
// Separate values and find line for main CPU load
foreach ($stats as $statLine)
{
$statLineData = explode(" ", trim($statLine));
// Found!
if
(
(count($statLineData) >= 5) &&
($statLineData[0] == "cpu")
)
{
return array(
$statLineData[1],
$statLineData[2],
$statLineData[3],
$statLineData[4],
);
}
}
}
}
return null;
}
// Returns server load in percent (just number, without percent sign)
function getServerLoad()
{
$load = null;
if (stristr(PHP_OS, "win"))
{
$cmd = "wmic cpu get loadpercentage /all";
@exec($cmd, $output);
if ($output)
{
foreach ($output as $line)
{
if ($line && preg_match("/^[0-9]+\$/", $line))
{
$load = $line;
break;
}
}
}
}
else
{
if (is_readable("/proc/stat"))
{
// Collect 2 samples - each with 1 second period
// See: https://de.wikipedia.org/wiki/Load#Der_Load_Average_auf_Unix-Systemen
$statData1 = _getServerLoadLinuxData();
sleep(1);
$statData2 = _getServerLoadLinuxData();
if
(
(!is_null($statData1)) &&
(!is_null($statData2))
)
{
// Get difference
$statData2[0] -= $statData1[0];
$statData2[1] -= $statData1[1];
$statData2[2] -= $statData1[2];
$statData2[3] -= $statData1[3];
// Sum up the 4 values for User, Nice, System and Idle and calculate
// the percentage of idle time (which is part of the 4 values!)
$cpuTime = $statData2[0] + $statData2[1] + $statData2[2] + $statData2[3];
// Invert percentage to get CPU time, not idle time
$load = 100 - ($statData2[3] * 100 / $cpuTime);
}
}
}
return $load;
}
//----------------------------
$cpuLoad = getServerLoad();
if (is_null($cpuLoad)) {
echo "CPU load not estimateable (maybe too old Windows or missing rights at Linux or Windows)";
}
else {
echo $cpuLoad . "%";
}
?>
