通过cronjob运行curl时，在哪里存储cookie

我有一个PHP脚本，登录到一个网站curl。当我在浏览器中运行脚本时，脚本可以正常登录。当我通过cronjob运行它时，它没有登录，因为cookie没有存储在我期望的位置。

如何存储cookie ?

这是脚本的相关部分。在此之前，定义了URL ($ URL)和登录数据($postrongtring)。

class curl {
    function __construct($use = 1) {
        $this->ch = curl_init();
        if($use = 1) {
            curl_setopt ($this->ch, CURLOPT_POST, 1);
            curl_setopt ($this->ch, CURLOPT_COOKIEJAR, $_SERVER['DOCUMENT_ROOT'].'/verwaltung/cookie.txt');
            curl_setopt ($this->ch, CURLOPT_COOKIEFILE, $_SERVER['DOCUMENT_ROOT'].'/verwaltung/cookie.txt');
            curl_setopt ($this->ch, CURLOPT_FOLLOWLOCATION, 1);
            curl_setopt ($this->ch, CURLOPT_RETURNTRANSFER, 1);
        } else {
            return 'There is the possibility, that this script wont work';
        }
    }
    function first_connect($loginform,$logindata) {
        curl_setopt($this->ch, CURLOPT_URL, $loginform);
        curl_setopt ($this->ch, CURLOPT_POSTFIELDS, $logindata);
    }
    function store() {
        $store = curl_exec ($this->ch);
    }
    function execute($page) {
        curl_setopt($this->ch, CURLOPT_URL, $page);
        $this->content = curl_exec ($this->ch);
    }
    function close() {
        curl_close ($this->ch);
    }
    function __toString() {
        return $this->content;
    }
}
$getit = new curl();
$getit->first_connect($url, $post_string);
$getit->store();
$getit->execute($url);
$getit->close();

经过编辑的问题反映了Wrikken和Colin Morelli的评论。谢谢你们两位!