PHP System Load on Mac OS X

#!/usr/bin/php
<?php
 
// This works with Mac OS X `uptime`
// others might require tweaks
 
error_reporting( E_ALL );
 
function load()
{
    $array = explode( ',', trim( `uptime` ) );
 
    while( list( , $value ) = each( $array ) )
    {
        if( eregi( 'load', $value ) )
        {
            $parts = explode( ':', trim( $value ) );
 
            $loads = explode( ' ', $parts[ count( $parts ) - 1 ] );
 
            $load = $loads[ 1 ];
 
            break;
        }
    }
 
    return $load;
}
 
echo load();
 
?>