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  • get_magic_quotes_gpc()

    (PHP 4, PHP 5, PHP 7)

    获取当前 magic_quotes_gpc 的配置选项设置

    说明

    get_magic_quotes_gpc(void): bool

    返回当前magic_quotes_gpc配置选项的设置

    记住,尝试在运行时设置magic_quotes_gpc将不会生效。

    更多关于 magic_quotes 的信息参见安全一章。

    返回值

    如果 magic_quotes_gpc 为关闭时返回 0,否则返回 1。在 PHP 5.4.O 起将始终返回FALSE

    更新日志

    版本说明
    5.4.0始终返回FALSE,因为这个魔术引号功能已经从 PHP 中移除了。

    范例

    Example #1get_magic_quotes_gpc()例子

    <?php
    // 如果启用了魔术引号
    echo $_POST['lastname'];             // O\'reilly
    echo addslashes($_POST['lastname']); // O\\\'reilly
    // 适用各个 PHP 版本的用法
    if (get_magic_quotes_gpc()) {
        $lastname = stripslashes($_POST['lastname']);
    }
    else {
        $lastname = $_POST['lastname'];
    }
    // 如果使用 MySQL
    $lastname = mysql_real_escape_string($lastname);
    echo $lastname; // O\'reilly
    $sql = "INSERT INTO lastnames (lastname) VALUES ('$lastname')";
    ?>
    

    注释

    Note:

    如果指令magic_quotes_sybase为 ON,它会完全覆盖magic_quotes_gpc。所以即使get_magic_quotes_gpc()返回TRUE,双引号、反斜杠或 NUL 都不会被转义。只有单引号会被转义。这种情况下它们看上去像:''

    参见

    @ dot dot dot dot dot alexander at gmail dot com
    I suggest replacing foreach by "stripslashes_deep":
    Using stripslashes() on an array on 
    <http://www.php.net/manual/en/function.stripslashes.php>:
    <?php
    function stripslashes_deep($value)
    {
      $value = is_array($value) ?
            array_map('stripslashes_deep', $value) :
            stripslashes($value);
      return $value;
    }
    ?>
    This gives:
    <?php
    if((function_exists("get_magic_quotes_gpc") && get_magic_quotes_gpc())  || (ini_get('magic_quotes_sybase') && (strtolower(ini_get('magic_quotes_sybase'))!="off")) ){
      stripslashes_deep($_GET);
      stripslashes_deep($_POST);
      stripslashes_deep($_COOKIE);
    }
    ?>
    
    Here's what I came up with to remove magic quotes from request data.
    Replaces two single-quotes with one if magic_quotes_sybase are on, otherwise it just strips slashes.
    Note that the `foreach` style makes this work only with PHP 5 and above.
    <?php
    // Strip magic quotes from request data.
    if (function_exists('get_magic_quotes_gpc') && get_magic_quotes_gpc()) {
      // Create lamba style unescaping function (for portability)
      $quotes_sybase = strtolower(ini_get('magic_quotes_sybase'));
      $unescape_function = (empty($quotes_sybase) || $quotes_sybase === 'off') ? 'stripslashes($value)' : 'str_replace("\'\'","\'",$value)';
      $stripslashes_deep = create_function('&$value, $fn', '
        if (is_string($value)) {
          $value = ' . $unescape_function . ';
        } else if (is_array($value)) {
          foreach ($value as &$v) $fn($v, $fn);
        }
      ');
      
      // Unescape data
      $stripslashes_deep($_POST, $stripslashes_deep);
      $stripslashes_deep($_GET, $stripslashes_deep);
      $stripslashes_deep($_COOKIE, $stripslashes_deep);
      $stripslashes_deep($_REQUEST, $stripslashes_deep);
    }
    ?>
    
    Please note, that when magic_quotes_gpc is set not only $_POST, $_GET, $_REQUEST, $_COOKIE arrays values are slashed. Actually every string value in $GLOBALS array is slashed, ie. $GLOBALS['_SERVER']['PATH_INFO'] (or $_SERVER['PATH_INFO']).
    <?php
    function stripper($stringvar){
      if (1 == get_magic_quotes_gpc()){
        $stringvar = stripslashes($stringvar);
      }
      return $stringvar;
    }
    ?>
    Usage:
    <?php
    $Body = stripper($rs->fields('Body'));
    echo($Body);
    ?>
    This checks if get_magic_quotes_gpc() is on and strips a string variable for output if its on. Useful if the dev server and live server are set up different.
    Re: php at kaiundina dot de (03-Feb-2005 02:18)
    1. magic_quotes_gpc=on/off and magic_quotes_sybase=on/off
    I made test and your function worked right. 
    These were the <input ... /> names I used:
    name="a"
    name="b.b b\b"
    name="c[c.1]"
    name="c[c 2]"
    name="c[c\3]"
    name="c.c c[c.' 4]"
    name="c ' c[c&quot;4]"
    name="d&quot;[d&quot;1]"
    (I used &quot; because I don't know other way to put " into the name)
    and the user-input value:
    a ' " \ \' \" \\ a
    2. > 17) The chars '.', ' ' are always replaced by '_' when used in keys.
    This is true only for the top-level keys, such as "b.b b\b", "c.c c" and "c ' c" above. The second-level key "[c.' 4]" was not changed to [c_'_4] but was escaped acording to how magic_quites_XXX are set.
    Tested on PHP 4.4.0.
    These magic_quotes are really black magic :(
    It'll be good to make test against $_SESSION, but I can't do it today.
    Escaping of key-strings in GPC-arrays behave different to the escaping of their values.
    First I expected that keys in submitted gpc-arrays are never escaped.
    Anyway. After I saw escaped keys, I assumed they're escaped according to the settings of magic quotes.
    ... it's even worse...
    It took me over 2 days of testing to figure out the exact behavior and creating two functions (one for each php-version) that strips slashes reliably from any array submitted to a script. Hope this saves someones time and nerves.
    The following is true for $_GET- and $_POST-arrays. I hope other arrays affected by magic quotes behave equally.
    I did not test the behavior for cases where magic_quotes_sybase is set.
    == legend for possible case combinations ==
    Px = php version we're using
      P4 = php 4.3.9
      P5 = php 5.0.2
    MQ = MagicQuotes GPC
      +MQ = magic quotes enabled
      -MQ = magic quotes disabled
    TL = TopLevel key
      +TL = key is on top level (i.e. $_GET['myKey'])
      -TL = key is nested within another array (i.e. $_GET['myList']['myKey'])
    AK = ArrayKey
      +AK = the value of the key is another array (i.e. is_array($_GET['myKey']) == true)
      -AK = the value is a normal string (i.e. is_string($_GET['myKey']) == true)
    == legend for possible results ==
    KE = KeyEscaping
      +KE = control chars are prefixed with a backslash
      -KE = key is returned as submitted and needn't to be stripped
    VE = ValueEscaping (doesn't apply for array as value)
      +VE = control chars are prefixed with a backslash
      -VE = value is returned as submitted and needn't to be stripped
    == here we go - the following rules apply ==
     1) P4 +MQ +AK +TL --> -KE
     2) P4 +MQ +AK -TL --> +KE
     3) P4 +MQ -AK +TL --> -KE +VE
     4) P4 +MQ -AK -TL --> +KE +VE
     5) P4 -MQ +AK +TL --> -KE
     6) P4 -MQ +AK -TL --> -KE
     7) P4 -MQ -AK +TL --> -KE -VE
     8) P4 -MQ -AK -TL --> -KE -VE
     9) P5 +MQ +AK +TL --> -KE
    10) P5 +MQ +AK -TL --> +KE
    11) P5 +MQ -AK +TL --> +KE +VE
    12) P5 +MQ -AK -TL --> +KE +VE
    13) P5 -MQ +AK +TL --> -KE
    14) P5 -MQ +AK -TL --> -KE
    15) P5 -MQ -AK +TL --> +KE -VE
    16) P5 -MQ -AK -TL --> +KE -VE
    17) The chars '.', ' ' are always replaced by '_' when used in keys.
    Example (rule 15):
    When running under php 5.0.2 having magic quotes disabled, gpc-keys on top level containing strings are escaped while their associated values are not.
    == The following function will strip GPC-arrays for php 4.3.9 ==
    <?php
    function transcribe($aList, $aIsTopLevel = true) {
      $gpcList = array();
      $isMagic = get_magic_quotes_gpc();
      
      foreach ($aList as $key => $value) {
        $decodedKey = ($isMagic && !$aIsTopLevel)?stripslashes($key):$key;
        if (is_array($value)) {
          $decodedValue = transcribe($value, false);
        } else {
          $decodedValue = ($isMagic)?stripslashes($value):$value;
        }
        $gpcList[$decodedKey] = $decodedValue;
      }
      return $gpcList;
    }
    ?>
    == The following function will strip GPC-arrays for php 5.0.2 ==
    <?php
    function transcribe($aList, $aIsTopLevel = true) {
      $gpcList = array();
      $isMagic = get_magic_quotes_gpc();
      
      foreach ($aList as $key => $value) {
        if (is_array($value)) {
          $decodedKey = ($isMagic && !$aIsTopLevel)?stripslashes($key):$key;
          $decodedValue = transcribe($value, false);
        } else {
          $decodedKey = stripslashes($key);
          $decodedValue = ($isMagic)?stripslashes($value):$value;
        }
        $gpcList[$decodedKey] = $decodedValue;
      }
      return $gpcList;
    }
    ?>
    Usage:
    <?php
    $unstrippedGET = transcribe($_GET);
    $unstrippedPOST = transcribe($_POST);
    ?>
    Maybe someone is willing to test those combinations for other php-versions and with magic_quotes_sybase set to 'on' - let me know.
    Sorry for this huge amount of text, but it's complete. I was unable to compress the decision table more than this.
    Just a little correction:
    ( Because of the ini_get function that may return a string value of "off" that evaluates to TRUE )
    <?php
        if(  
          ( function_exists("get_magic_quotes_gpc") && get_magic_quotes_gpc() )
           || ( ini_get('magic_quotes_sybase') && ( strtolower(ini_get('magic_quotes_sybase')) != "off" ) )
          ){
          foreach($_GET as $k => $v) $_GET[$k] = stripslashes($v);
          foreach($_POST as $k => $v) $_POST[$k] = stripslashes($v);
          foreach($_COOKIE as $k => $v) $_COOKIE[$k] = stripslashes($v);
        }
    ?>
    
    When you work with forms and databases you should use this concept:
    1.When inserting the user input in DB escape $_POST/$_GET with add_slashes() or similar (to match the speciffic database escape rules)
    $query='INSERT INTO users SET fullname="'.add_slashes($_POST['fullname']).'"';
    insert_into_db($query);
    2.When reading a previously submitted input from DB use html_special_chars to display an escaped result!
    read_db_row('SELECT fullname FROM users');
    echo '<input type="text" name="fullname" value="'.html_special_chars($db_row['fullname']).'" />
    this way you safely store and work with the original(unescaped) data.
    > "If the directive magic_quotes_sybase is ON it will completely override magic_quotes_gpc."
    This "note" is a bit misleading. magic_quotes_sybase will only override the escaping method used on Get/Post/Cookie data if magic_quotes_gpc is already enabled. If magic_quotes_gpc is not enabled then magic_quotes_sybase will have no effect here.
    A few of the other comments are therefore incorrect in determining when to "stripslashes" from the input, by "stripping slashes" when either magic_quotes_gpc OR magic_quotes_sybase is enabled. You should only stripslashes() when magic_quotes_gpc is enabled since that is the only time when slashes are automatically added.
    stripslashes() is also magic_quotes_sybase aware, so you don't need to do anything special (ie. write a custom function to handle this situation as another comment suggests) when magic_quotes_sybase is enabled. When magic_quotes_sybase is enabled, stripslashes() does not actually strip any slashes, but instead unescapes single-quotes that are escaped with single-quotes only.
    magic_quotes_sybase does however influence the escaping (and unescaping) method used by addslashes() and stripslashes() respectively, regardless of whether magic_quotes_gpc (or magic_quotes_runtime) is enabled.
    Regarding the three main strip methods as found below (two using foreach, 1 using the json method), I've done a little benchmarking using 'true' profiling (using a registered tickhandler where declare(ticks=1)).
    I wondered whether or not json would not be terribly slow.
    I won't discuss the profiler, but will suffice with the following statement, followed by the used code to benchmark:
    The json method was by FAR the quickest (contrary to what I'd thought), so if you need a speedy process, use that!
    <?php
    declare(ticks=1);
    function g()
    {
      return array(
        'a'=>'i\\\\\\'m',
        array('a1' => 'x', 'b1' => 'x'),
        array( 'a2' => array('a3' => '\\\\\\'x', 'b3' => 'random' )
        )
      );
    }
    function strip_json($d)
    {
      $rs = json_decode(stripslashes(json_encode($d, JSON_HEX_APOS)), true);
      return $rs;
    }
    function strip_deep1($d)
    {
      foreach ($d as $k=>$v)
      {
        if (is_array($v)) { $d[$k] = strip_deep1($v); }
        else { $d[$k] = stripslashes($v); }
      }
      return $d;
    }
    function strip_deep2(&$d)
    {
      $d = is_array($d) ? array_map('strip_deep2', $d) : stripslashes($d);
      return $d;
    }
    // now profile it
    require_once './TickProfiler.php';
    $N = 1000;
    $d = g();
    TickProfiler::Register();
    for ($i = 0; $i < $N; $i++){ strip_json($d); }
    for ($i = 0; $i < $N; $i++){ strip_deep1($d); }
    for ($i = 0; $i < $N; $i++){ strip_deep2($d); }
    TickProfiler::Unregister();
    TickProfiler::Display();
    ?>
    My output (PHP 5.3.1, win32):
      [TickProfiler::tick] => Array
        (
          [time] => 0.76188707351685
          [calls] => 46001
        )
      [TickProfiler::Register] => Array
        (
          [time] => 3.0994415283203E-5
          [calls] => 1
        )
      [strip_json] => Array
        (
          [time] => 0.025638580322266
          [calls] => 1000
        )
      [strip_deep1] => Array
        (
          [time] => 0.40303444862366
          [calls] => 36000
        )
      [strip_deep2] => Array
        (
          [time] => 0.14928555488586
          [calls] => 9000
        )
    )
    As can be seen above, using json speeds output by at least a factor of 5 (nearly 6).
    Just wanted to share this :D
    Do note the strip_json function has two LOC instead of a plain return statement, otherwise it wouldn't get picked up by the tickprofiler (it would return from the code immediately, never reaching the profiler)!
    Usage of the return statement in strip_deep2 is not needed, as the argument is passed by reference.
    A new test showed that the time penalty for this is about 0.09 seconds.
    This actually means that the factor between strip_deep2 vs strip_json is only about 2.
    Still, strip_json would be about twice as fast as strip_deep2