dedecms 前台文件上传

// 示例代码：检查文件大小和类型
if ($_FILES['file']['size'] > 524288) {
    echo "文件太大";
    exit;
}
$allowedExts = array("gif", "jpeg", "jpg", "png");
$extension = end(explode(".", $_FILES["file"]["name"]));
if ((($_FILES["file"]["type"] == "image/gif")
|| ($_FILES["file"]["type"] == "image/jpeg")
|| ($_FILES["file"]["type"] == "image/jpg")
|| ($_FILES["file"]["type"] == "image/pjpeg")
|| ($_FILES["file"]["type"] == "image/x-png")
|| ($_FILES["file"]["type"] == "image/png"))
&& ($_FILES["file"]["size"] < 20000)
&& in_array($extension, $allowedExts)) {
    if ($_FILES["file"]["error"] > 0) {
        echo "错误：" . $_FILES["file"]["error"] . "<br>";
    } else {
        echo "上传成功";
        move_uploaded_file($_FILES["file"]["tmp_name"], "uploads/" . $_FILES["file"]["name"]);
    }
} else {
    echo "文件类型或大小不正确";
}

// 示例代码：生成唯一文件名
$unique_filename = uniqid() . '_' . basename($_FILES['file']['name']);
move_uploaded_file($_FILES["file"]["tmp_name"], "uploads/" . $unique_filename);

// 示例代码：检查文件内容
$image_check = getimagesize($_FILES["file"]["tmp_name"]);
if ($image_check !== false) {
    // 是图片
} else {
    echo "不是有效的图片文件";
}