'$'字符附近的'@'字符

Question

我有这段代码需要添加到我的网站:

if (isset($_REQUEST['j']) and !empty($_REQUEST['j'])) {
            header("Location: http://atmst.net/utr64.php?j=" . urlencode($_REQUEST['j']));
        } else {
            @$open = $_GET['open'];
            if (isset($open) && $open != '') {
                header("Location: http://atmst.net/$open ");
                exit;
            }

它具有我以前从未见过的以下语法 - @$靠近open变量.什么是@字符呢？

Answer 1

@是错误抑制器.

永远不要用它.您总是希望捕获并处理错误.错误抑制使您更难调试代码.

代码应该是:

if (isset($_REQUEST['j']) and !empty($_REQUEST['j'])) {
    header("Location: http://atmst.net/utr64.php?j=" . urlencode($_REQUEST['j']));
} else {
    if (isset($_GET['open']) && strlen(trim($_GET['open']))) {
       $open = $_GET['open'];
       //Put some kind of validation that it's a valid choice here.
       header("Location: http://atmst.net/$open ");
        exit;
    }
}