Фильтры очистки

    Список фильтров очистки
    Идентификатор Имя Флаги Описание
    FILTER_SANITIZE_ENCODED "encoded" FILTER_FLAG_STRIP_LOW, FILTER_FLAG_STRIP_HIGH, FILTER_FLAG_STRIP_BACKTICK, FILTER_FLAG_ENCODE_LOW, FILTER_FLAG_ENCODE_HIGH Кодирует строку в формат URL-адреса, и, если требуется, удаляет или кодирует специальные символы.
    FILTER_SANITIZE_SPECIAL_CHARS "special_chars" FILTER_FLAG_STRIP_LOW, FILTER_FLAG_STRIP_HIGH, FILTER_FLAG_STRIP_BACKTICK, FILTER_FLAG_ENCODE_HIGH Кодирует символы '"<>& и символы с ASCII-кодом меньше 32 в HTML-сущности, и, если нужно, удаляет или кодирует остальные специальные символы.
    FILTER_SANITIZE_FULL_SPECIAL_CHARS "full_special_chars" FILTER_FLAG_NO_ENCODE_QUOTES Эквивалент вызова функции htmlspecialchars() с параметром ENT_QUOTES. Кодирование кавычек отключают установкой флага FILTER_FLAG_NO_ENCODE_QUOTES. Как и функция htmlspecialchars(), этот фильтр учитывает директиву default_charset, и если в последовательности байтов будет обнаружен недопустимый для текущей кодировки символ, то вся строка будет забракована, а результатом будет строка нулевой длины. При установке этого фильтра в качестве фильтра по умолчанию учитывают предупреждение, которое изложено ниже, оно рассказывает об установке флагам по умолчанию значения 0.
    FILTER_SANITIZE_STRING "string" FILTER_FLAG_NO_ENCODE_QUOTES, FILTER_FLAG_STRIP_LOW, FILTER_FLAG_STRIP_HIGH, FILTER_FLAG_STRIP_BACKTICK, FILTER_FLAG_ENCODE_LOW, FILTER_FLAG_ENCODE_HIGH, FILTER_FLAG_ENCODE_AMP Удаляет теги и кодирует двойные и одинарные кавычки, а если нужно, удаляет или кодирует специальные символы. Кодирование кавычек можно отключить, установив FILTER_FLAG_NO_ENCODE_QUOTES. (Объявлен устаревшим начиная с PHP 8.1.0, используйте вместо него функцию htmlspecialchars()).
    FILTER_UNSAFE_RAW "unsafe_raw" FILTER_FLAG_STRIP_LOW, FILTER_FLAG_STRIP_HIGH, FILTER_FLAG_STRIP_BACKTICK, FILTER_FLAG_ENCODE_LOW, FILTER_FLAG_ENCODE_HIGH, FILTER_FLAG_ENCODE_AMP Бездействует, и, если нужно, удаляет или кодирует специальные символы. Этот фильтр — псевдоним фильтра FILTER_DEFAULT.

    Список изменений

    Версия Описание
    8.1.0 Фильтры FILTER_SANITIZE_STRING и FILTER_SANITIZE_STRIPPED объявлены устаревшими.

    Улучшение страницы

    Инструкция • Исправление • Сообщение об ошибке
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    Примечания пользователей 10 notes

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    69
    googlybash24 at aol dot com
    12 years ago
    Remember to trim() the $_POST before your filters are applied:

    <?php

    // We trim the $_POST data before any spaces get encoded to "%20"

    // Trim array values using this function "trim_value"
    function trim_value(&$value)
    {
    $value = trim($value); // this removes whitespace and related characters from the beginning and end of the string
    }
    array_filter($_POST, 'trim_value'); // the data in $_POST is trimmed

    $postfilter = // set up the filters to be used with the trimmed post array
    array(
    'user_tasks' => array('filter' => FILTER_SANITIZE_STRING, 'flags' => !FILTER_FLAG_STRIP_LOW), // removes tags. formatting code is encoded -- add nl2br() when displaying
    'username' => array('filter' => FILTER_SANITIZE_ENCODED, 'flags' => FILTER_FLAG_STRIP_LOW), // we are using this in the url
    'mod_title' => array('filter' => FILTER_SANITIZE_ENCODED, 'flags' => FILTER_FLAG_STRIP_LOW), // we are using this in the url
    );

    $revised_post_array = filter_var_array($_POST, $postfilter); // must be referenced via a variable which is now an array that takes the place of $_POST[]
    echo (nl2br($revised_post_array['user_tasks'])); //-- use nl2br() upon output like so, for the ['user_tasks'] array value so that the newlines are formatted, since this is our HTML <textarea> field and we want to maintain newlines
    ?>
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    3
    terry dot marsault at gmail dot com
    6 months ago
    None of these parameters do answer my need, so I've made my own function, hope it helps some other folks!

    function removeSpecialChars($valueToClean)
    {
    return htmlspecialchars(str_replace([",", "#", "$", "%", "*", "~", "'", "=", "{", "[", "|", "`", "^", "]", "}", ":", ";", "<", ">", "/", "?", "&"], "", $valueToClean));
    }
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    61
    Anonymous
    9 years ago
    FILTER_SANITIZE_STRING doesn't behavior the same as strip_tags function. strip_tags allows less than symbol inferred from context, FILTER_SANITIZE_STRING strips regardless.
    <?php
    $smaller     = "not a tag < 5";
    echo     strip_tags($smaller); // -> not a tag < 5
    echo filter_var ( $smaller, FILTER_SANITIZE_STRING); // -> not a tag
    ?>
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    13
    finkenb2 at msu dot edu
    11 months ago
    With the deprecation of FILTER_SANITIZE_STRING, the "use htmlspecialchars instead" is an incomplete comment. The functionality of FILTER_SANITIZE_STRING was a combination of htmlspcialchars and (approximately) strip_tags. For true compatibility a polyfil may be needed:

    <?php
    function filter_string_polyfill(string $string): string
    {
    $str = preg_replace('/\x00|<[^>]*>?/', '', $string);
    return     str_replace(["'", '"'], ['&#39;', '&#34;'], $str);
    }

    $string = "Some \"' <bizzare> string & to Sanitize < !$@%";
    echo     filter_var($string,FILTER_SANITIZE_STRING).PHP_EOL;
    //Some &#34;&#39; string & to Sanitize

    echo htmlspecialchars($string).PHP_EOL;
    //Some &quot;&#039; &lt;bizzare&gt; string &amp; to Sanitize &lt; !$@%

    echo strip_tags($string).PHP_EOL;
    //Some "' string & to Sanitize < !$@%

    echo htmlspecialchars(strip_tags($string,ENT_QUOTES)).PHP_EOL;
    //Some &quot;&#039; string &amp; to Sanitize &lt; !$@%

    echo filter_string_polyfill($string).PHP_EOL;
    //Some &#34;&#39; string & to Sanitize
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    16
    ipse at sergiosantos dot me
    3 years ago
    Although it's specifically mentioned in the above documentation, because many seem to find this unintuitive it's worth pointing out that FILTER_SANITIZE_NUMBER_FLOAT will remove the decimal character unless you specify FILTER_FLAG_ALLOW_FRACTION:

    <?php
    $number_string     = '12.34';

    echo     filter_var( $number_string, FILTER_SANITIZE_NUMBER_FLOAT ); // 1234

    echo filter_var( $number_string, FILTER_SANITIZE_NUMBER_FLOAT, FILTER_FLAG_ALLOW_FRACTION ); // 12.34
    ?>
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    28
    Willscrlt
    8 years ago
    To include multiple flags, simply separate the flags with vertical pipe symbols.

    For example, if you want to use filter_var() to sanitize $string with FILTER_SANITIZE_STRING and pass in FILTER_FLAG_STRIP_HIGH and FILTER_FLAG_STRIP_LOW, just call it like this:

    $string = filter_var($string, FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_HIGH | FILTER_FLAG_STRIP_LOW);

    The same goes for passing a flags field in an options array in the case of using callbacks.

    $var = filter_var($string, FILTER_SANITIZE_SPECIAL_CHARS,
    array('flags' => FILTER_FLAG_STRIP_LOW | FILTER_FLAG_ENCODE_HIGH));

    Thanks to the Brain Goo blog at popmartian.com/tipsntricks/for this info.
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    23
    marcus at synchromedia dot co dot uk
    14 years ago
    It's not entirely clear what the LOW and HIGH ranges are. LOW is characters below 32, HIGH is those above 127, i.e. outside the ASCII range.

    <?php
    $a     = "\tcafé\n";
    //This will remove the tab and the line break
    echo filter_var($a, FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_LOW);
    //This will remove the é.
    echo filter_var($a, FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_HIGH);
    ?>
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    16
    AntonioPrimera
    8 years ago
    Please be aware that when using filter_var() with FILTER_SANITIZE_NUMBER_FLOAT and FILTER_SANITIZE_NUMBER_INT the result will be a string, even if the input value is actually a float or an int.

    Use FILTER_VALIDATE_FLOAT and FILTER_VALIDATE_INT, which will convert the result to the expected type.
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    13
    galvao at galvao dot eti dot br
    11 years ago
    Just to clarify, since this may be unknown for a lot of people:

    ASCII characters above 127 are known as "Extended" and they represent characters such as greek letters and accented letters in latin alphabets, used in languages such as pt_BR.

    A good ASCII quick reference (aside from the already mentioned Wikipedia article) can be found at: http://www.asciicodes.com/
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    5
    david dot drakulovski at gmail dot com
    10 years ago
    Here is a simpler and a better presented ASCII list for the <32 or 127> filters
    (if wikipedia confused the hell out of you):

    http://www.danshort.com/ASCIImap/
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