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PHP中spl_autoload_register函数的用法

Fri, 30 Oct 2009 01:32:54 +0000

spl_autoload_register
(PHP 5 >= 5.1.2)

spl_autoload_register — 注册__autoload()函数

说明
bool spl_autoload_register ([ callback $autoload_function ] )
将函数注册到SPL __autoload函数栈中。如果该栈中的函数尚未激活，则激活它们。

如果在你的程序中已经实现了__autoload函数，它必须显式注册到__autoload栈中。因为

spl_autoload_register()函数会将Zend Engine中的__autoload函数取代为spl_autoload()或

spl_autoload_call()。

参数

autoload_function
欲注册的自动装载函数。如果没有提供任何参数，则自动注册autoload的默认实现函数

spl_autoload()。

返回值
如果成功则返回 TRUE，失败则返回 FALSE。

注：SPL是Standard PHP Library(标准PHP库)的缩写。它是PHP5引入的一个扩展库，其主要功能包括autoload机制的实现及包括各种Iterator接口或类。SPL autoload机制的实现是通过将函数指针autoload_func指向自己实现的具有自动装载功能的函数来实现的。SPL有两个不同的函数spl_autoload, spl_autoload_call，通过将autoload_func指向这两个不同的函数地址来实现不同的自动加载机制。

范例
load.php文件

class LOAD
{
static function loadClass($class_name)
    {
        $filename = $class_name.".class.php";
$path = "include/".$filename
        if (is_file($path)) return include $path;
    }
}

/**
* 设置对象的自动载入
* spl_autoload_register — Register given function as __autoload() implementation
*/
spl_autoload_register(array('LOAD', 'autoload'));

同时对多个表做相同操作

Fri, 30 Oct 2009 01:06:41 +0000

原文：Making changes to many tables at once

As an alternative to another recent blog post that answered the question “how can I truncate all the tables in my database,” I thought I’d show another way to do it, which does not use the INFORMATION_SCHEMA.

$ wget http://www.maatkit.org/get/mk-find
$ perl mk-find --exec 'TRUNCATE TABLE %D.%N'

The other example is how to alter MyISAM tables to be InnoDB. That one’s easy, too. Let’s alter all MyISAM tables in the ‘test’ database:

$ wget http://www.maatkit.org/get/mk-find
$ perl mk-find test --engine MyISAM --exec 'ALTER TABLE %D.%N ENGINE=InnoDB'

If you want to print out the commands instead of executing them, you can just use –printf instead of –exec.

Why would you do it this way instead of through the INFORMATION_SCHEMA database? I don’t think this can be said too often: querying the INFORMATION_SCHEMA database on MySQL can completely lock a busy server for a long time. It can even crash it. It is very dangerous. So whenever I mention it, I mention the dangers of using it. I use it too sometimes, but only when I know the server I’m working on.

zsync http协议文件同步工具

Fri, 30 Oct 2009 01:04:59 +0000

值得试试，http://zsync.moria.org.uk/ 不知道跟webdav协议有多大区别。

zsync is a file transfer program. It allows you to download a file from a remote server, where you have a copy of an older version of the file on your computer already. zsync downloads only the new parts of the file. It uses the same algorithm as rsync. However, where rsync is designed for synchronising data from one computer to another within an organisation, zsync is designed for file distribution, with one file on a server to be distributed to thousands of downloaders. zsync requires no special server software ??just a web server to host the files ??and imposes no extra load on the server, making it ideal for large scale file distribution.

zsync is open source, distributed under version 2 of the Artistic License. Feedback, bugs reports and patches are welcome.

AIDE Advanced Intrusion Detection Enviornment) 文件审计tripwire替代品

Sat, 24 Oct 2009 13:02:40 +0000

AIDE (Advanced Intrusion Detection Enviornment) is a tool to check the file integrity. It is an opensource substitute for TRIPWIRE. It allows to take snapshots of all the major configuration files, binaries as well as libraries stats. And helps to find which binaries have been changed in case of compromisation of the system. This can be downloaded from http://sourceforge.net.

Download both the binaries and signature file. Import and verify the GPG keys.

Compiling and installing AIDE

Read the INSTALL doc in the source code of AIDE to get the requirements of the packages. The mhash utility is needed prior to the installation of AIDE. Download the mhash utility that is needed for running AIDE. Download it from sourceforge.net.

Extract the packages AIDE & MHASH.

Installing MHASH:

# tar -zxvf mhash-0.9.2.tar.gz
# cd mhash-0.9.2
# ./configure
# make
# make install

This will place the binaries and libraries in /usr/local.

Installing AIDE:

# tar -zxvf aide-0.10.tar.gz
# cd aide-0.10
# ./configure
# make "this will create the aide binary"
# make install

This will copy the binaries to /usr/local/bin.

Note: Making notes of the md5sum for the binary which has been installed is a good idea to track man-in-the-middle attacks.

Configuring and monitoring files with AIDE

Step 1. Generate the AIDE DB (creating the snapshot of file stats).

Edit the aide.conf configuration file from the aide-0.10/doc/ directory to define the rules which directory has to be monitored.

# 3 type of line are there
#    1. variables
#    2. Macros
#    3. types of file, which includes the directories, to monitor.
database=file:/home/kiran/aide/aide.db (this will define the aide database store location)
#Now define here the aide rules
#This will monitor all the subdirectories beneath /etc/
/etc R
# check the defnition for R in the aide.conf file.
#=/etc/ R (Only etc directory will be monitored)

Now create the AIDE DB.

# aide -c aide.conf --init

This will create a new database called aide.db.new. This command will scan all the files in the /etc/ directory and stores them as a database called aide.db.new.

Note: AIDE uses the stat command to get the details of the file including the permissions, inode, acess time, modified time etc. and will store them in the aide.db file.

Comparing AIDE with the DB:

# aide -c aide.conf --check

This will show the status of the current /etc/ subdirectory by comparing with the aide.db, the snapshot taken from the previous command.

Now test the AIDE functionality.

Edit any file in the /etc/ subdirectory.

Now check again with the command:

# aide -c aide.conf --check

This will show the changes of the file from a previous state.

Note: The aide --check has to be done frequently. And if we find any changes, verify them and again update the aide DB.

Updating the aide DB after checking the aide db:

# aide -c aide.conf --update

This will reset the database to the current status of the /etc/ subdirectory.

Including more directories to monitor:

Edit aide.conf:

/boot  R
/bin   R
/etc   R
/lib   R
/usr   R
/install   R
/sbin$   R #aide will not recurse in to the subdirectories

Other configuration options:

/ R
!/var  # This will make to monitor all the directories inside the "/" and will exclude the /var directory.

# aide -c aide.conf --init

This will generate a new DB for all the directories defined in the aide.conf.

Note: This will help us to trace out which file has been effected in case any compromise happened to the system by comparison with the DB taken prior. Once we have the aide db created it's better to burn the aide binary config files and the aide db to any read-only medium. So this will increase the integrity of the aide DB.

# mkisofs -V Aide_DB`date +%F` -J -R -o aide.iso /Aide/directory
# cdrecord -v -eject aide.iso

Later in case of any suspicion of an exploit you can load these binaries, aide DB and config file for AIDE audit.

linux 监视工具

Sat, 24 Oct 2009 12:53:12 +0000

dstat
非常有用的 vmstat 替代品, 用过都说好. 可以写插件. 可以调不少参数.
因为看 vmstat 习惯了, 所以推荐关掉颜色显示 (否则看着乱).
IBM 有个 nmon, 最大的优点和缺点都是全屏幕.

memstat
man 中说 Identify what’s using up virtual memory.

multitail
看日志的.

nethogs
监控网络活动. 可以看看数据包大小的分布情况, 可能对你做网络优化之类的工作有启发.

iotop
好像有 C 重写版. 监控进程对磁盘的操作.

iptraf
监控进程对网络的操作.

strace & ltrace
试试就知道. 一用都说好.

wine
说到 wine 可能就觉得是个模拟器(当然, Wine Is Not an Emulator) / 上层结构.
wine 有几个参数可以用来调试 win32 程序.
如
WINEDEBUG=+winsock wine app.exe
但偶并不希望这种调试方式被用于做一些不好的事情.

既然对某 fg 和 U 的分析论文已经出炉, 偶也无意再用这种方法做一次同样的分析.
这种工具落到这种人手里则最为可悲, 只可惜他们决心已定, 再难也要干这些不好的事情, 公开或者不公开, 用什么样的工具也就没什么区别了.
说出来, 帮助一下那些有需要的人吧. 做黑箱的千万别问偶这东西怎么用.

这场闹剧以 Port 8080 Tunnel 的出现而暂时休止. 而闹剧无论怎样改头换面, 它还是闹剧.

继续拖时间:
authbind, dnsutils, autossh, chkrootkit, cronolog, dmidecode, keychain
也许还可以开一个比较系列. 比如 (以下排第一的都是偶的选择)
network-manager VS wicd
file-roller VS xarchiver
chmsee VS gnochm VS xchm
xfce4 VS lxde+openbox (gnome, KDE 之类好久没用过了, 没什么发言权)
qbittorrent VS transmission VS deluge (基于命令行的就先算了?)

最后一句:
偶停止了大部分的静态 pecl 编译入 php 活动. 抽空开文章讨论.
简而言之, 这是个节约一点点时间却非常浪费内存的事情.