PHP file upload related restrictions

Upload related restrictions

1 Client restrictions

请选择您要上传的文件：

The input attributes are used to limit the size and type of uploaded files, but personal feelings: First, the html code is "visible "; Second, it often doesn't work (I didn't find the reason, but because of the first one I also want to give up on it, just know it.

2 Server-side restrictions

Main restrictions on size and type , and then there is the method.

$maxsize) {
        exit("上传文件过大！");
    }
    if (!in_array($ext, $allowExt)) {
        exit("非法文件类型");
    }
    if (!is_uploaded_file($tmp_name)) {
        exit("上传方式有误，请使用post方式");
    }
    if (@move_uploaded_file($tmp_name, $uniName)) {//@错误抑制符，不让用户看到警告
        echo "文件".$filename."上传成功!";
    }else{
        echo "文件".$filename."上传失败!";
    }
    //判断是否为真实图片（防止伪装成图片的病毒一类的
    if (!getimagesize($tmp_name)) {//getimagesize真实返回数组，否则返回false
        exit("不是真正的图片类型");
    }
}else{
    switch ($error){
        case 1:
            echo "超过了上传文件的最大值，请上传2M以下文件";
            break;
        case 2:
            echo "上传文件过多，请一次上传20个及以下文件！";
            break;
        case 3:
            echo "文件并未完全上传，请再次尝试！";
            break;
        case 4:
            echo "未选择上传文件！";
            break;
        case 7:
            echo "没有临时文件夹";
            break;
    }
}

Here, the specific implementation is commented, you can actually try it yourself, it is very interesting

3 Encapsulation

Function

$maxSize) {
        exit("上传文件过大！");
    }
    if (!in_array($ext, $allowExt)) {
        exit("非法文件类型");
    }
    if (!is_uploaded_file($tmp_name)) {
        exit("上传方式有误，请使用post方式");
    }
    //判断是否为真实图片（防止伪装成图片的病毒一类的
    if (!getimagesize($tmp_name)) {//getimagesize真实返回数组，否则返回false
        exit("不是真正的图片类型");
    }
    if (@move_uploaded_file($tmp_name, $destination)) {//@错误抑制符，不让用户看到警告
        echo "文件".$filename."上传成功!";
    }else{
        echo "文件".$filename."上传失败!";
    }
    
}else{
    switch ($error){
        case 1:
            echo "超过了上传文件的最大值，请上传2M以下文件";
            break;
        case 2:
            echo "上传文件过多，请一次上传20个及以下文件！";
            break;
        case 3:
            echo "文件并未完全上传，请再次尝试！";
            break;
        case 4:
            echo "未选择上传文件！";
            break;
        case 7:
            echo "没有临时文件夹";
            break;
    }
}
return $destination;
}

call

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