filter_input

    (PHP 5 >= 5.2.0, PHP 7, PHP 8)

    filter_input — 指定した名前の変数を外部から受け取り、オプションでそれをフィルタリングする

    説明

    filter_input(
        int $type,
        string $var_name,
        int $filter = FILTER_DEFAULT,
        array|int $options = 0
    ): mixed

    パラメータ

    type

    INPUT_GET、INPUT_POST、 INPUT_COOKIE、INPUT_SERVER あるいは INPUT_ENV のいずれか。

    var_name

    取得する変数の名前。

    filter

    適用するフィルタの ID。フィルタの型 に、利用できるフィルタの一覧があります。

    省略した場合は FILTER_DEFAULT を使います。これは FILTER_UNSAFE_RAW と同等です。 結果的に、デフォルトでは何もフィルタリングをしません。

    options

    オプションあるいはフラグの論理和の連想配列。 オプションを指定可能なフィルタの場合、この配列の "flags" フィールドにフラグを指定します。

    戻り値

    成功した場合は要求された変数の値、フィルタリングに失敗した場合に false、 あるいは変数 var_name が設定されていない場合に null を返します。フラグ FILTER_NULL_ON_FAILURE が指定されている場合は、変数が設定されていなければ false、 フィルタリングに失敗したら null を返します。

    例

    例1 filter_input() の例

    <?php
    $search_html     = filter_input(INPUT_GET, 'search', FILTER_SANITIZE_SPECIAL_CHARS);
    $search_url = filter_input(INPUT_GET, 'search', FILTER_SANITIZE_ENCODED);
    echo     "You have searched for $search_html.\n";
    echo     "<a href='?search=$search_url'>Search again.</a>";
    ?>

    上の例の出力は、 たとえば以下のようになります。

    You have searched for Me &#38; son.
<a href='?search=Me%20%26%20son'>Search again.</a>

    参考

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    User Contributed Notes 9 notes

    up
    100
    CertaiN
    10 years ago
    This function provides us the extremely simple solution for type filtering.

    Without this function...
    <?php
    if (!isset($_GET['a'])) {
    $a = null;
    } elseif (!    is_string($_GET['a'])) {
    $a = false;
    } else {
    $a = $_GET['a'];
    }
    $b = isset($_GET['b']) && is_string($_GET['b']) ? $_GET['b'] : '';
    ?>

    With this function...
    <?php
    $a     = filter_input(INPUT_GET, 'a');
    $b = (string)filter_input(INPUT_GET, 'b');
    ?>

    Yes, FILTER_REQUIRE_SCALAR seems to be set as a default option.
    It's very helpful for eliminating E_NOTICE, E_WARNING and E_ERROR.
    This fact should be documented.
    up
    48
    anthony dot parsons at manx dot net
    17 years ago
    FastCGI seems to cause strange side-effects with unexpected null values when using INPUT_SERVER and INPUT_ENV with this function. You can use this code to see if it affects your server:
    <?php
    var_dump    ($_SERVER);
    foreach (     array_keys($_SERVER) as $b ) {
    var_dump($b, filter_input(INPUT_SERVER, $b));
    }
    echo     '<hr>';
    var_dump($_ENV);
    foreach (     array_keys($_ENV) as $b ) {
    var_dump($b, filter_input(INPUT_ENV, $b));
    }
    ?>
    If you want to be on the safe side, using the superglobal $_SERVER and $_ENV variables will always work. You can still use the filter_* functions for Get/Post/Cookie without a problem, which is the important part!
    up
    41
    rimelek at rimelek dot hu
    10 years ago
    If your $_POST contains an array value:
    <?php
    $_POST     = array(
    'var' => array('more', 'than', 'one', 'values')
    );
    ?>
    you should use FILTER_REQUIRE_ARRAY option:
    <?php
    var_dump    (filter_input(INPUT_POST, 'var', FILTER_DEFAULT , FILTER_REQUIRE_ARRAY));
    ?>
    Otherwise it returns false.
    up
    32
    ss23 at ss23 dot geek dot nz
    14 years ago
    Note that this function doesn't (or at least doesn't seem to) actually filter based on the current values of $_GET etc. Instead, it seems to filter based off the original values.
    <?php
    $_GET    ['search'] = 'foo'; // This has no effect on the filter_input

    $search_html = filter_input(INPUT_GET, 'search', FILTER_SANITIZE_SPECIAL_CHARS);
    $search_url = filter_input(INPUT_GET, 'search', FILTER_SANITIZE_ENCODED);
    echo     "You have searched for $search_html.\n";
    echo     "<a href='?search=$search_url'>Search again.</a>";
    ?>

    If you need to set a default input value and filter that, use filter_var on your required input variable instead
    up
    22
    Stefan Weinzierl
    10 years ago
    Here is an example how to work with the options-parameter. Notice the 'options' in the 'options'-Parameter!

    <?php
    $options    =array('options'=>array('default'=>5, 'min_range'=>0, 'max_range'=>9));

    $priority=filter_input(INPUT_GET, 'priority', FILTER_VALIDATE_INT, $options);
    ?>

    $priority will be 5 if the priority-Parameter isn't set or out the given range.
    up
    10
    chris at chlab dot ch
    12 years ago
    To use a class method for a callback function, as usual, provide an array with an instance of the class and the method name.
    Example:

    <?php
    class myValidator
    {
    public function     username($value)
    {
    // return username or boolean false
    }
    }

    $myValidator = new myValidator;
    $options = array('options' => array($myValidator, 'username'));
    $username = filter_input(INPUT_GET, 'username', FILTER_CALLBACK, $options);
    var_dump($username);
    ?>
    up
    4
    akshay dot leadindia at gmail dot com
    11 years ago
    The beauty of using this instead of directly using filter_var( $_GET['search'] ) is that you don't need to check if( isset( $_GET['search'] ) ) as if you pass that to filter_var and the key is not set then it will result in a warning. This function simplifies this and will return the relevant result to you (as per your options set) if the key has not been set in the user input.

    If the type of filter you are using also supports a 'default' argument then this function will also stuff your missing input key with that value, again saving your efforts
    up
    5
    travismowens at gmail dot com
    14 years ago
    I wouldn't recommend people use this function to store their data in a database. It's best not to encode data when storing it, it's better to store it raw and convert in upon the time of need.

    One main reason for this is because if you have a short CHAR(16) field and the text contains encoded characters (quotes, ampersand) you can easily take a 12 character entry which obviously fits, but because of encoding it no longer fits.

    Also, while not as common, if you need to use this data in another place, such as a non webpage (perhaps in a desktop app, or to a cell phone SMS or to a pager) the HTML encoded data will appear raw, and now you have to decode the data.

    In summary, the best way to architect your system, is to store data as raw, and encode it only the moment you need to. So this means in your PHP upon doing a SQL query, instead of merely doing an echo $row['title'] you need to run htmlentities() on your echos, or better yet, an abstract function.
    up
    0
    HonzaZ
    2 years ago
    In fastcgi sapi implementations, filter_input(INPUT_SERVER) can return empty results.

    In my case (8.1.9 64bit php-cgi) it was caused by auto_globals_jit enabled . When disabled (in php.ini on php startup), filter_input(INPUT_SERVER) works correctly.

    php-fpm sapi isn't affected.
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