php计算几分钟前、几小时前、几天前的几个函数

/*php计算几分钟前、几小时前、几天前的几个函数*/
function get_date($time){
    $t=time()-$time;
    $f=array(
        ‘31536000‘=>‘年‘,
        ‘2592000‘=>‘个月‘,
        ‘604800‘=>‘星期‘,
        ‘86400‘=>‘天‘,
        ‘3600‘=>‘小时‘,
        ‘60‘=>‘分钟‘,
        ‘1‘=>‘秒‘
    );
    foreach ($f as $k=>$v)    {
        if (0 !=$c=floor($t/(int)$k)) {
            return $c.$v.‘前‘;
        }
    }
}