num_cpus.php

<?php


/**
 * returns number of cpu cores
 * Copyleft 2018, license: WTFPL 
 * @throws \RuntimeException
 * @throws \LogicException
 * @return int
 */
function num_cpu(): int {
	if (defined ( 'PHP_WINDOWS_VERSION_MAJOR' )) {
		$str = trim ( shell_exec ( 'wmic cpu get NumberOfCores 2>&1' ) );
		if (! preg_match ( '/(\d+)/', $str, $matches )) {
			throw new \RuntimeException ( 'wmic failed to get number of cpu cores on windows!' );
		}
		return (( int ) $matches [1]);
	}
	$ret = @shell_exec ( 'nproc' );
	if (is_string ( $ret )) {
		$ret = trim ( $ret );
		if (false !== ($tmp = filter_var ( $ret, FILTER_VALIDATE_INT ))) {
			return $tmp;
		}
	}
	if (is_readable ( '/proc/cpuinfo' )) {
		$cpuinfo = file_get_contents ( '/proc/cpuinfo' );
		$count = substr_count ( $cpuinfo, 'processor' );
		if ($count > 0) {
			return $count;
		}
	}
	throw new \LogicException( 'failed to detect number of CPUs!' );
}