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    urldecode

    (PHP 4, PHP 5, PHP 7, PHP 8)

    urldecode — URL エンコードされた文字列をデコードする

    説明

    urldecode(string $string): string

    与えられた文字列中のあらゆるエンコード文字 %## をデコードします。 プラス記号 ('+') は、スペース文字にデコードします。

    パラメータ

    string

    デコードする文字列。

    戻り値

    デコードした文字列を返します。

    例

    例1 urldecode() の例

    <?php
    $query     = "my=apples&are=green+and+red";

    foreach (    explode('&', $query) as $chunk) {
    $param = explode("=", $chunk);

    if (    $param) {
    printf("Value for parameter \"%s\" is \"%s\"<br/>\n", urldecode($param[0]), urldecode($param[1]));
    }
    }
    ?>

    注意

    警告

    スーパーグローバル $_GET および $_REQUEST の内容はすでにデコード済みのものです。 $_GET や $_REQUEST の要素に対して urldecode() を使用すると、予期せぬ危険な結果となります。

    参考

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    User Contributed Notes 5 notes

    up
    37
    alejandro at devenet dot net
    14 years ago
    When the client send Get data, utf-8 character encoding have a tiny problem with the urlencode.
    Consider the "º" character.
    Some clients can send (as example)
    foo.php?myvar=%BA
    and another clients send
    foo.php?myvar=%C2%BA (The "right" url encoding)

    in this scenary, you assign the value into variable $x

    <?php
    $x     = $_GET['myvar'];
    ?>

    $x store: in the first case "�" (bad) and in the second case "º" (good)

    To fix that, you can use this function:

    <?php
    function to_utf8( $string ) {
    // From http://w3.org/International/questions/qa-forms-utf-8.html
    if ( preg_match('%^(?:
    [\x09\x0A\x0D\x20-\x7E] # ASCII
    | [\xC2-\xDF][\x80-\xBF] # non-overlong 2-byte
    | \xE0[\xA0-\xBF][\x80-\xBF] # excluding overlongs
    | [\xE1-\xEC\xEE\xEF][\x80-\xBF]{2} # straight 3-byte
    | \xED[\x80-\x9F][\x80-\xBF] # excluding surrogates
    | \xF0[\x90-\xBF][\x80-\xBF]{2} # planes 1-3
    | [\xF1-\xF3][\x80-\xBF]{3} # planes 4-15
    | \xF4[\x80-\x8F][\x80-\xBF]{2} # plane 16
    )*$%xs'    , $string) ) {
    return     $string;
    } else {
    return     iconv( 'CP1252', 'UTF-8', $string);
    }
    }
    ?>

    and assign in this way:

    <?php
    $x     = to_utf8( $_GET['myvar'] );
    ?>

    $x store: in the first case "º" (good) and in the second case "º" (good)

    Solve a lot of i18n problems.

    Please fix the auto-urldecode of $_GET var in the next PHP version.

    Bye.

    Alejandro Salamanca
    up
    13
    Visual
    18 years ago
    If you are escaping strings in javascript and want to decode them in PHP with urldecode (or want PHP to decode them automatically when you're putting them in the query string or post request), you should use the javascript function encodeURIComponent() instead of escape(). Then you won't need any of the fancy custom utf_urldecode functions from the previous comments.
    up
    4
    tomas at penajaca dot com dot br
    21 years ago
    urldecode does not decode "%0" bypassing it. I can cause troble when you are working with fixed lenght strings.

    You can you the function below.

    function my_urldecode($string){

    $array = split ("%",$string);

    if (is_array($array)){
    while (list ($k,$v) = each ($array)){
    $ascii = base_convert ($v,16,10);
    $ret .= chr ($ascii);
    }
    }
    return ("$ret");
    }
    up
    3
    Joe
    16 years ago
    It's worth pointing out that if you are using AJAX and need to encode strings that are being sent to a PHP application, you may not need to decode them in PHP.

    <?php
    echo stripslashes(nl2br($_POST['message']));
    ?>

    Will properly output a message sent with the javascript code if the message is encoded:

    message = encodeURIComponent(message)

    And is sent with an AJAX POST request with the header:
    ajaxVar.setRequestHeader('Content-type', 'application/x-www-form-urlencoded')
    up
    1
    bloodjazman at gmail dot com
    4 years ago
    "+" replaced by space according to HTML x-www-form-url-encoded media type
    see http://www.faqs.org/rfcs/rfc1866.html
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