php扩展加载

1. “php中扩展库”是什么意思如何加载

扩展库是php扩展的功能,比如php本来不支持操作某种功能 ,但在新版本想对它提供支持,就以扩展的方式来提供,这样,我们在配置php时,如果我们不用此功能,我们就可以让php不加载他.从而节省服务器资源.提供其性能
php的扩展库一般放在php目录下的ext目录里.你在网上下载的php压缩包解压后应该可以看到.
php.ini中的 extension_dir 用来指定你的扩展名的地址 。
php.ini中有一排像 ;extension="xxxxxx.dll" 的内容就是用来配置让你的php运行环境支持什么不支持什么。
以下为php.ini中的剪切段
------------------------------
;extension=php_bz2.dll
;extension=php_curl.dll
;extension=php_dba.dll
;extension=php_dbase.dll
;extension=php_exif.dll
;extension=php_fdf.dll
;extension=php_gd2.dll //php对图片操作的扩展
;extension=php_gettext.dll
;extension=php_gmp.dll
;extension=php_ifx.dll
;extension=php_imap.dll
;extension=php_interbase.dll
;extension=php_ldap.dll
;extension=php_mbstring.dll
;extension=php_mcrypt.dll
;extension=php_mhash.dll
;extension=php_mime_magic.dll
;extension=php_ming.dll
;extension=php_msql.dll
;extension=php_mssql.dll //php操作mssql (sql server)数据库的扩展
;extension=php_mysql.dll //php操作mysql数据库的扩展
------------------------------
要让php支持某种功能,把extension前面的 " ; "号去掉,重启apache或iis即可。

2. linux 怎么看php扩展模块是否加载成功

静态只要一启动就能加载
动态用的时候才加载
.so
/usr/local/php5/bin/php
-i
|less
查看配置文件在哪里，编译参数
/usr/local/php5/bin/php
-m
|less
查看php加载的模块

3. 如何加载php扩展功能

当服务器上PHP已经安装好，需要额外添加PHP扩展时怎么办？不需要重新安装PHP，有了phpize我们可以在原有的PHP基础之上直接安装扩展库。
这次编译仅仅只是单独编译PHP的扩展库，接下来将编译好的扩展库加入到现在运行的php中，不对现在运行的php重新编译，所以没有一点的影响。

下面我们演示安装xsl的扩展（不一定常用，仅做为一个范例）
做法一：
1.找到当前运行的php版本的源代码目录，如php-5.2.3。进入xsl扩展库目录。
$cd /home/pkgs/php-5.3.3/ext/xsl

2.调用phpize程序生成编译配置文件。
$/home/app/php5.3.3/bin/phpize

3.编译扩展库，分别执薯仔岩行下面的configure和make命令。
$./configure-with-php-config=/home/app/php5.3.3/bin/php-config
这一步执行通过后，再执行make命令，如果configure执行不通过，则查找错误原因。

$make
#make成功执行后，生成的扩展库文件在当前目录的 moles子目录下，
如/home/php-5.3.3/ext/curl/moles/xsl.so

4.配置php.ini文件
#将编译好的扩展库文件复制到PHP的扩展目录下，可通过查看phpinfo信息。。
$ cp /home/pkg/php-5.3.3/ext/xsl/moles/xsl.so /home/app/php5.3.3/lib/php/extensions/no-debug-non-zts-20090626

#在php.ini文件中找到设置扩展目录的位置，然后将扩展路径设置到php安装目录/extension/no-debug-non....目录下，并添加扩展库位置。
extension_dir /home/app/php5.3.3/lib/php/extensions/no-debug-non-zts-20090626”
extension=xsl.so

5.重启php，查看phpinfo信息戚此，即可看到刚才添加进去的xsl扩展库。（如果有多个php-fpm进程的话，平滑重启数御主进程即可：kill -USR2 pid）

4. win7下安装Apache2.4+php5.6之后，不能加载php扩展模块

尝试如下操作：
1、 在php.ini中设置extension_dir 指向e:\php5.4\ext; 部分php扩展加载了
2、设置windows系统环境变量， phpext, 指向e:\php5.4\ext， PHPRC 指向e:\php5.4
设置path环境变量，添加e:\php5.4
3、重新启动apache

5. php安装的问题，无法载入 mysql 扩展，请检查 PHP 配置

首先你需要将PHP安装目录下的php_mysql.dll和php_mysqli.dll（我的在D:\apptools\php5\ext目录下）复制到c:\windows\system32目录下，然后修改php.ini文件（需要放到c:\windows目录下），关键是extension=php_mysql.dll 和extension_dir = "D:/apptools/php5/ext"。
我的配置是这样的：

[PHP]

;;;;;;;;;;;
; WARNING ;
;;;;;;;;;;;
; This is the default settings file for new PHP installations.
; By default, PHP installs itself with a configuration suitable for
; development purposes, and *NOT* for proction purposes.
; For several security-oriented considerations that should be taken
; before going online with your site, please consult php.ini-recommended
; and http://php.net/manual/en/security.php.

;;;;;;;;;;;;;;;;;;;
; About php.ini ;
;;;;;;;;;;;;;;;;;;;
; This file controls many aspects of PHP's behavior. In order for PHP to
; read it, it must be named 'php.ini'. PHP looks for it in the current
; working directory, in the path designated by the environment variable
; PHPRC, and in the path that was defined in compile time (in that order).
; Under Windows, the compile-time path is the Windows directory. The
; path in which the php.ini file is looked for can be overridden using
; the -c argument in command line mode.
;
; The syntax of the file is extremely simple. Whitespace and Lines
; beginning with a semicolon are silently ignored (as you probably guessed).
; Section headers (e.g. [Foo]) are also silently ignored, even though
; they might mean something in the future.
;
; Directives are specified using the following syntax:
; directive = value
; Directive names are *case sensitive* - foo=bar is different from FOO=bar.
;
; The value can be a string, a number, a PHP constant (e.g. E_ALL or M_PI), one
; of the INI constants (On, Off, True, False, Yes, No and None) or an expression
; (e.g. E_ALL & ~E_NOTICE), or a quoted string ("foo").
;
; Expressions in the INI file are limited to bitwise operators and parentheses:
; | bitwise OR
; & bitwise AND
; ~ bitwise NOT
; ! boolean NOT
;
; Boolean flags can be turned on using the values 1, On, True or Yes.
; They can be turned off using the values 0, Off, False or No.
;
; An empty string can be denoted by simply not writing anything after the equal
; sign, or by using the None keyword:
;
; foo = ; sets foo to an empty string
; foo = none ; sets foo to an empty string
; foo = "none" ; sets foo to the string 'none'
;
; If you use constants in your value, and these constants belong to a
; dynamically loaded extension (either a PHP extension or a Zend extension),
; you may only use these constants *after* the line that loads the extension.
;
;
;;;;;;;;;;;;;;;;;;;
; About this file ;
;;;;;;;;;;;;;;;;;;;
; All the values in the php.ini-dist file correspond to the builtin
; defaults (that is, if no php.ini is used, or if you delete these lines,
; the builtin defaults will be identical).

;;;;;;;;;;;;;;;;;;;;
; Language Options ;
;;;;;;;;;;;;;;;;;;;;

; Enable the PHP scripting language engine under Apache.
engine = On

; Enable compatibility mode with Zend Engine 1 (PHP 4.x)
zend.ze1_compatibility_mode = Off

; Allow the <? tag. Otherwise, only <?php and <script> tags are recognized.
; NOTE: Using short tags should be avoided when developing applications or
; libraries that are meant for redistribution, or deployment on PHP
; servers which are not under your control, because short tags may not
; be supported on the target server. For portable, redistributable code,
; be sure not to use short tags.
short_open_tag = On

; Allow ASP-style <% %> tags.
asp_tags = Off

; The number of significant digits displayed in floating point numbers.
precision = 12

; Enforce year 2000 compliance (will cause problems with non-compliant browsers)
y2k_compliance = On

; Output buffering allows you to send header lines (including cookies) even
; after you send body content, at the price of slowing PHP's output layer a
; bit. You can enable output buffering ring runtime by calling the output
; buffering functions. You can also enable output buffering for all files by
; setting this directive to On. If you wish to limit the size of the buffer
; to a certain size - you can use a maximum number of bytes instead of 'On', as
; a value for this directive (e.g., output_buffering=4096).
output_buffering = On

; You can redirect all of the output of your scripts to a function. For
; example, if you set output_handler to "mb_output_handler", character
; encoding will be transparently converted to the specified encoding.
; Setting any output handler automatically turns on output buffering.
; Note: People who wrote portable scripts should not depend on this ini
; directive. Instead, explicitly set the output handler using ob_start().
; Using this ini directive may cause problems unless you know what script
; is doing.
; Note: You cannot use both "mb_output_handler" with "ob_iconv_handler"
; and you cannot use both "ob_gzhandler" and "zlib.output_compression".
; Note: output_handler must be empty if this is set 'On' !!!!
; Instead you must use zlib.output_handler.
;output_handler =

; Transparent output compression using the zlib library
; Valid values for this option are 'off', 'on', or a specific buffer size
; to be used for compression (default is 4KB)
; Note: Resulting chunk size may vary e to nature of compression. PHP
; outputs chunks that are few hundreds bytes each as a result of
; compression. If you prefer a larger chunk size for better
; performance, enable output_buffering in addition.
; Note: You need to use zlib.output_handler instead of the standard
; output_handler, or otherwise the output will be corrupted.
zlib.output_compression = Off

; You cannot specify additional output handlers if zlib.output_compression
; is activated here. This setting does the same as output_handler but in
; a different order.
;zlib.output_handler =

; Implicit flush tells PHP to tell the output layer to flush itself
; automatically after every output block. This is equivalent to calling the
; PHP function flush() after each and every call to print() or echo() and each
; and every HTML block. Turning this option on has serious performance
; implications and is generally recommended for debugging purposes only.
implicit_flush = Off

; The unserialize callback function will be called (with the undefined class'
; name as parameter), if the unserializer finds an undefined class
; which should be instantiated.
; A warning appears if the specified function is not defined, or if the
; function doesn't include/implement the missing class.
; So only set this entry, if you really want to implement such a
; callback-function.
unserialize_callback_func=

; When floats & doubles are serialized store serialize_precision significant
; digits after the floating point. The default value ensures that when floats
; are decoded with unserialize, the data will remain the same.
serialize_precision = 100

; Whether to enable the ability to force arguments to be passed by reference
; at function call time. This method is deprecated and is likely to be
; unsupported in future versions of PHP/Zend. The encouraged method of
; specifying which arguments should be passed by reference is in the function
; declaration. You're encouraged to try and turn this option Off and make
; sure your scripts work properly with it in order to ensure they will work
; with future versions of the language (you will receive a warning each time
; you use this feature, and the argument will be passed by value instead of by
; reference).
allow_call_time_pass_reference = On

;
; Safe Mode
;
safe_mode = Off

; By default, Safe Mode does a UID compare check when
; opening files. If you want to relax this to a GID compare,
; then turn on safe_mode_gid.
safe_mode_gid = Off

; When safe_mode is on, UID/GID checks are bypassed when
; including files from this directory and its subdirectories.
; (directory must also be in include_path or full path must
; be used when including)
safe_mode_include_dir =

; When safe_mode is on, only executables located in the safe_mode_exec_dir
; will be allowed to be executed via the exec family of functions.
safe_mode_exec_dir =

; Setting certain environment variables may be a potential security breach.
; This directive contains a comma-delimited list of prefixes. In Safe Mode,
; the user may only alter environment variables whose names begin with the
; prefixes supplied here. By default, users will only be able to set
; environment variables that begin with PHP_ (e.g. PHP_FOO=BAR).
;
; Note: If this directive is empty, PHP will let the user modify ANY
; environment variable!
safe_mode_allowed_env_vars = PHP_

; This directive contains a comma-delimited list of environment variables that
; the end user won't be able to change using putenv(). These variables will be
; protected even if safe_mode_allowed_env_vars is set to allow to change them.
safe_mode_protected_env_vars = LD_LIBRARY_PATH

; open_basedir, if set, limits all file operations to the defined directory
; and below. This directive makes most sense if used in a per-directory
; or per-virtualhost web server configuration file. This directive is
; *NOT* affected by whether Safe Mode is turned On or Off.
;open_basedir =

; This directive allows you to disable certain functions for security reasons.
; It receives a comma-delimited list of function names. This directive is
; *NOT* affected by whether Safe Mode is turned On or Off.
disable_functions =

; This directive allows you to disable certain classes for security reasons.
; It receives a comma-delimited list of class names. This directive is
; *NOT* affected by whether Safe Mode is turned On or Off.
disable_classes =

; Colors for Syntax Highlighting mode. Anything that's acceptable in
; <span style="color: ???????"> would work.
;highlight.string = #DD0000
;highlight.comment = #FF9900
;highlight.keyword = #007700
;highlight.bg = #FFFFFF
;highlight.default = #0000BB
;highlight.html = #000000

; If enabled, the request will be allowed to complete even if the user aborts
; the request. Consider enabling it if executing long request, which may end up
; being interrupted by the user or a browser timing out.
; ignore_user_abort = On

;
; Misc
;
; Decides whether PHP may expose the fact that it is installed on the server
; (e.g. by adding its signature to the Web server header). It is no security
; threat in any way, but it makes it possible to determine whether you use PHP
; on your server or not.
expose_php = On

;;;;;;;;;;;;;;;;;;;
; Resource Limits ;
;;;;;;;;;;;;;;;;;;;

max_execution_time = 3000 ; Maximum execution time of each script, in seconds
max_input_time = 60 ; Maximum amount of time each script may spend parsing request data
memory_limit = 8M ; Maximum amount of memory a script may consume (8MB)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Error handling and logging ;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

; error_reporting is a bit-field. Or each number up to get desired error
; reporting level
; E_ALL - All errors and warnings (doesn't include E_STRICT)
; E_ERROR - fatal run-time errors
; E_WARNING - run-time warnings (non-fatal errors)
; E_PARSE - compile-time parse errors
; E_NOTICE - run-time notices (these are warnings which often result
; from a bug in your code, but it's possible that it was
; intentional (e.g., using an uninitialized variable and
; relying on the fact it's automatically initialized to an
; empty string)
; E_STRICT - run-time notices, enable to have PHP suggest changes
; to your code which will ensure the best interoperability
; and forward compatibility of your code
; E_CORE_ERROR - fatal errors that occur ring PHP's initial startup
; E_CORE_WARNING - warnings (non-fatal errors) that occur ring PHP's
; initial startup
; E_COMPILE_ERROR - fatal compile-time errors
; E_COMPILE_WARNING - compile-time warnings (non-fatal errors)
; E_USER_ERROR - user-generated error message
; E_USER_WARNING - user-generated warning message
; E_USER_NOTICE - user-generated notice message
;
; Examples:
;
; - Show all errors, except for notices and coding standards warnings
;
;error_reporting = E_ALL & ~E_NOTICE
;
; - Show all errors, except for notices
;
;error_reporting = E_ALL & ~E_NOTICE | E_STRICT
;
; - Show only errors
;
;error_reporting = E_COMPILE_ERROR|E_ERROR|E_CORE_ERROR
;
; - Show all errors except for notices and coding standards warnings
;
error_reporting = E_ALL & ~E_NOTICE

; Print out errors (as a part of the output). For proction web sites,
; you're strongly encouraged to turn this feature off, and use error logging
; instead (see below). Keeping display_errors enabled on a proction web site
; may reveal security information to end users, such as file paths on your Web
; server, your database schema or other information.
display_errors = On

; Even when display_errors is on, errors that occur ring PHP's startup
; sequence are not displayed. It's strongly recommended to keep
; display_startup_errors off, except for when debugging.
display_startup_errors = Off

; Log errors into a log file (server-specific log, stderr, or error_log (below))
; As stated above, you're strongly advised to use error logging in place of
; error displaying on proction web sites.
log_errors = Off

; Set maximum length of log_errors. In error_log information about the source is
; added. The default is 1024 and 0 allows to not apply any maximum length at all.
log_errors_max_len = 1024

; Do not log repeated messages. Repeated errors must occur in same file on same
; line until ignore_repeated_source is set true.
ignore_repeated_errors = Off

; Ignore source of message when ignoring repeated messages. When this setting
; is On you will not log errors with repeated messages from different files or
; sourcelines.
ignore_repeated_source = Off

; If this parameter is set to Off, then memory leaks will not be shown (on
; stdout or in the log). This has only effect in a debug compile, and if
; error reporting includes E_WARNING in the allowed list
report_memleaks = On

; Store the last error/warning message in $php_errormsg (boolean).
track_errors = Off

; Disable the inclusion of HTML tags in error messages.
; Note: Never use this feature for proction boxes.
;html_errors = Off

; If html_errors is set On PHP proces clickable error messages that direct
; to a page describing the error or function causing the error in detail.
; You can download a of the PHP manual from http://www.php.net/docs.php
; and change docref_root to the base URL of your local including the
; leading '/'. You must also specify the file extension being used including
; the dot.
; Note: Never use this feature for proction boxes.
;docref_root = "/phpmanual/"
;docref_ext = .html

; String to output before an error message.
;error_prepend_string = "<font color=ff0000>"

; String to output after an error message.
;error_append_string = "</font>"

; Log errors to specified file.
;error_log = filename

; Log errors to syslog (Event Log on NT, not valid in Windows 95).
;error_log = syslog

;;;;;;;;;;;;;;;;;
; Data Handling ;
;;;;;;;;;;;;;;;;;
;
; Note - track_vars is ALWAYS enabled as of PHP 4.0.3

; The separator used in PHP generated URLs to separate arguments.
; Default is "&".
;arg_separator.output = "&"

; List of separator(s) used by PHP to parse input URLs into variables.
; Default is "&".
; NOTE: Every character in this directive is considered as separator!
;arg_separator.input = ";&"

; This directive describes the order in which PHP registers GET, POST, Cookie,
; Environment and Built-in variables (G, P, C, E & S respectively, often
; referred to as EGPCS or GPC). Registration is done from left to right, newer
; values override older values.
variables_order = "EGPCS"

; Whether or not to register the EGPCS variables as global variables. You may
; want to turn this off if you don't want to clutter your scripts' global scope
; with user data. This makes most sense when coupled with track_vars - in which
; case you can access all of the GPC variables through the $HTTP_*_VARS[],
; variables.
;
; You should do your best to write your scripts so that they do not require
; register_globals to be on; Using form variables as globals can easily lead
; to possible security problems, if the code is not very well thought of.
register_globals = On

; Whether or not to register the old-style input arrays, HTTP_GET_VARS
; and friends. If you're not using them, it's recommended to turn them off,
; for performance reasons.
register_long_arrays = On

; This directive tells PHP whether to declare the argv&argc variables (that
; would contain the GET information). If you don't use these variables, you
; should turn it off for increased performance.
register_argc_argv = On

; When enabled, the SERVER and ENV variables are created when they're first
; used (Just In Time) instead of when the script starts. If these variables
; are not used within a script, having this directive on will result in a
; performance gain. The PHP directives register_globals, register_long_arrays,
; and register_argc_argv must be disabled for this directive to have any affect.
auto_globals_jit = On

; Maximum size of POST data that PHP will accept.
post_max_size = 8M

; Magic quotes
;

; Magic quotes for incoming GET/POST/Cookie data.
magic_quotes_gpc = On

; Magic quotes for runtime-generated data, e.g. data from SQL, from exec(), etc.
magic_quotes_runtime = Off

; Use Sybase-style magic quotes (escape ' with '' instead of \').
magic_quotes_sybase = Off

; Automatically add files before or after any PHP document.
auto_prepend_file =
auto_append_file =

; As of 4.0b4, PHP always outputs a character encoding by default in
; the Content-type: header. To disable sending of the charset, simply
; set it to be empty.
;
; PHP's built-in default is text/html
default_mimetype = "text/html"
;default_charset = "iso-8859-1"

; Always populate the $HTTP_RAW_POST_DATA variable.
;always_populate_raw_post_data = On

;;;;;;;;;;;;;;;;;;;;;;;;;
; Paths and Directories ;
;;;;;;;;;;;;;;;;;;;;;;;;;

; UNIX: "/path1:/path2"
;include_path = ".:/php/includes"
;
; Windows: "\path1;\path2"
include_path = ".;D:\apptools\php5\PEAR"

; The root of the PHP pages, used only if nonempty.
; if PHP was not compiled with FORCE_REDIRECT, you SHOULD set doc_root
; if you are running php as a CGI under any web server (other than IIS)
; see documentation for security issues. The alternate is to use the
; cgi.force_redirect configuration below
doc_root =

; The directory under which PHP opens the script using /~username used only
; if nonempty.
user_dir =

; Directory in which the loadable extensions (moles) reside.
extension_dir = "D:/apptools/php5/ext"

; Whether or not to enable the dl() function. The dl() function does NOT work
; properly in multithreaded servers, such as IIS or Zeus, and is automatically
; disabled on them.
enable_dl = On