杂类问题

有些问题没法归到其它类中,可以在这里找到。

在 Windows 中怎样处理 bz2 压缩的文档?

如果没有能处理 bz2 文件的压缩工具,从 Redhat » 下载一个命令行工具(进一步信息见下面)。

如果不喜欢用命令行工具,可以试试免费工具例如 » Stuffit Expander» UltimateZip» 7-Zip或者 » Quick Zip。如果有像 » WinRAR或者 » Power Archiver之类的工具,可以很容易用它解压缩 bz2 文件。如果用 Total Commander(前身为 Windows Commander),可以从 » Total Commander网站免费得到一个 bz2 插件。

来自 Redhat 的 bzip2 命令行工具:

Win2K Sp2 用户下载最新版本 1.0.2,所有其它 Windows 用户应该用版本 1.00。下载后重命名可执行文件为 bzip2.exe。为方便起见将其放到一个在你路径中的目录,例如 C:\Windows,C 表示你安装 Windows 的盘符。

注意:lang 指的是你的语种,x 是想要的格式,例如:pdf。要解压缩 php_manual_lang.x.bz2,按照下面的简单说明进行:

  • 打开一个命令行窗口
  • 进入存放已下载的 php_manual_lang.x.bz2 的目录
  • 调用 bzip2 -d php_manual_lang.x.bz2,将 php_manual_lang.x 释放到同一个目录

在下载了包含很多 html 文件的 php_manual_lang.tar.bz2 的情况下,过程是一样的。唯一区别是得到了一个 php_manual_lang.tar 文件。tar 格式可以被大多数 Windows 下流行的压缩工具所处理,例如 » WinZip

在函数定义中,参数旁边的 & 是什么意思?例如 asort()

这表示该参数是 引用传递,该函数会修改其值。只可以用此方法传递变量,其实都不需要在函数调用中用 & 传递(此方式都已 过时了)。

怎么处理 register_globals

有关 register_globals实现方面的安全性,请阅读 使用 register_globals一章。

推荐使用 超全局变量而不要依赖 register_globals

如果需要在一台关闭了 register_globals的共享主机上运行一些旧式程序而该程序需要此选项打开时,或者在一些打开了此选项的主机上但想消除安全隐患,那么就需要用 PHP 来模拟出相反的设定。最好先问清楚是否能否在哪里更改 PHP 配置的选项,如果不行,那可以用如下的兼容手段。

Example #1 模拟注册全局变量

本例模拟 register_globals On。如果改变了配置文件中的 variables_order选项,则考虑对 $superglobals作出相应的改动。

<?php
// Emulate register_globals on
if (!ini_get('register_globals')) {
    
$superglobals = array($_SERVER$_ENV,
        
$_FILES$_COOKIE$_POST$_GET);
    if (isset(
$_SESSION)) {
        
array_unshift($superglobals$_SESSION);
    }
    foreach (
$superglobals as $superglobal) {
        
extract($superglobalEXTR_SKIP);
    }
}
?>

本例模拟 register_globals Off。要记住此代码应在脚本最开头的地方调用。如果使用了会话机制,则在 session_start()之后调用。

<?php
// Emulate register_globals off
function unregister_GLOBALS()
{
    if (!
ini_get('register_globals')) {
        return;
    }

    
// Might want to change this perhaps to a nicer error
    
if (isset($_REQUEST['GLOBALS']) || isset($_FILES['GLOBALS'])) {
        die(
'GLOBALS overwrite attempt detected');
    }

    
// Variables that shouldn't be unset
    
$noUnset = array('GLOBALS',  '_GET',
                     
'_POST',    '_COOKIE',
                     
'_REQUEST''_SERVER',
                     
'_ENV',     '_FILES');

    
$input array_merge($_GET,    $_POST,
                         
$_COOKIE$_SERVER,
                         
$_ENV,    $_FILES,
                         isset(
$_SESSION) && is_array($_SESSION) ? $_SESSION : array());

    foreach (
$input as $k => $v) {
        if (!
in_array($k$noUnset) && isset($GLOBALS[$k])) {
            unset(
$GLOBALS[$k]);
        }
    }
}

unregister_GLOBALS();

?>

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User Contributed Notes 4 notes

up
1
php at REMOVEMEkennel17 dot co dot uk
9 years ago
Regarding simulating register_globals = off, note that it is impossible to adequately prevent $_SESSION variables from being globalised, as the array (and thus the globals) are created on a call to session_start().  You would therefore have to 'undo' this when you start a session as using it at the start of your script will have no effect.

To avoid potential problems, use a prefix that is unique for all session variables (e.g. 'SESS_'), and only access them via the $_SESSION array.  The prefix ensures that you don't have a naming clash (and therefore a security risk) with any non-session globals.
up
0
interessa at elzorro dot net
1 day ago
Form di login e registrazione con php

    Salve a tutti, rivelo di non essere esperto il linguaggio informatico. Vorrei inserire una pagina di login e registrazione nel mio sito altervista in modo che alcuni articoli siano visualizzabili solo dagli utenti iscritti. Ho letto molti tutorial, ma non ho capito da dove bisogna cominciare. Ho solo sentito nomi di formati oppure nomi come phpadmin o mysql. Ma non capisco niente . Sarei molto grato se mi aiutaste scrivendo passo per passo come fare. Ho capito qualcosa, però.
    Ho capito come si creano le pagine php e ho anche provato ad usare phpadmin, ma non so come inserire tutto nel mio sito.
    Posso arrivare al punto critico di permettere un utente di inserire personalmente il form login, siccome è difficile spiegare passo per passo come mi devo comportare. Il mio sito è www.interessa.altervista.org
    Grazie mille,
    interessa@elzorro.net

    (POTETE CONTATTARMI PER MAIL, SE VOLETE )
up
-1
doerr at apkk dot de
4 years ago
If you only needed register_globals for get/post variables, the effictive solution for 5.3 is:
  import_request_variables("GPC", "");

But if the skripts relied on session_register() you'll have to do more:
- Replace all variables that appeared after session_register with _SESSION equivalents - so $myvar becomes $_SESSION['myvar']
- Take care if your variables appeared inside strings - 'Hello $user !' works, but 'Hello $_SESSION['user'] !' not - so you have to concatenate the string: 'Hello '.$_SESSION['user'] .' !'
- Session variables in function declarations (for whatever purpose) will not work - keeping the old (local) names will work in most cases.
- Finally, replace the session_register(..) line with session_start()
up
-4
markus
9 years ago
Considering the comment below. I think there's a way to avoid that "problem":

<?php
//
// $starttime is an example of a variable that we might need to define,
// even before, running the "register_globals OFF" emulator below.
//
list($msec, $sec) = explode(' ', microtime());
$starttime = ((float)$msec + (float)$sec);

//
// If register_globals is ON, ensure no unexpected globals are defined.
// ie. We'll try to emulate a register_globals OFF environment.
//
if( (bool)@ini_get('register_globals') )
{
   
$superglobals = array($_ENV, $_GET, $_POST, $_COOKIE, $_FILES, $_SERVER);
    if( isset(
$_SESSION) )
    {
       
array_unshift($superglobals, $_SESSION);
    }
   
$knownglobals = array(
       
//
        // Known PHP Reserved globals and superglobals:
        //
       
'_ENV',        'HTTP_ENV_VARS',
       
'_GET',        'HTTP_GET_VARS',
       
'_POST',    'HTTP_POST_VARS',
       
'_COOKIE',    'HTTP_COOKIE_VARS',
       
'_FILES',    'HTTP_FILES_VARS',
       
'_SERVER',    'HTTP_SERVER_VARS',
       
'_SESSION',    'HTTP_SESSION_VARS',
       
'_REQUEST',

       
//
        // Global variables used by this code snippet:
        //
       
'superglobals',
       
'knownglobals',
       
'superglobal',
       
'global',
       
'void',

       
//
        // Known global variables defined before this code snippet is reached.
        //
       
'starttime',
    );
    foreach(
$superglobals as $superglobal )
    {
        foreach(
$superglobal as $global => $void )
        {
            if( !
in_array($global, $knownglobals) )
            {
                unset(
$GLOBALS[$global]);
            }
        }
    }
}
?>

Note the stuff related to the $_SESSION array depends on whether the PHP session has been started or not. You might want to call session_start() before this point (or set session.auto_start ON).

HTH+ :)
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