PHP.ini研究 php.ini中文版

[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 ; ;;;;;;;;;;;;;;;;;;; ; This is the recommended, PHP 5-style version of the php.ini-dist file. It ; sets some non standard settings, that make PHP more efficient, more secure, ; and encourage cleaner coding. ; ; The price is that with these settings, PHP may be incompatible with some ; applications, and sometimes, more difficult to develop with. Using this ; file is warmly recommended for production sites. As all of the changes from ; the standard settings are thoroughly documented, you can go over each one, ; and decide whether you want to use it or not. ; ; For general information about the php.ini file, please consult the php.ini-dist ; file, included in your PHP distribution. ; ; This file is different from the php.ini-dist file in the fact that it features ; different values for several directives, in order to improve performance, while ; possibly breaking compatibility with the standard out-of-the-box behavior of ; PHP. Please make sure you read what's different, and modify your scripts ; accordingly, if you decide to use this file instead. ; ; - register_long_arrays = Off [Performance] ; Disables registration of the older (and deprecated) long predefined array ; variables ($HTTP_*_VARS). Instead, use the superglobals that were ; introduced in PHP 4.1.0 ; - display_errors = Off [Security] ; With this directive set to off, errors that occur during the execution of ; scripts will no longer be displayed as a part of the script output, and thus, ; will no longer be exposed to remote users. With some errors, the error message ; content may expose information about your script, web server, or database ; server that may be exploitable for hacking. Production sites should have this ; directive set to off. ; - log_errors = On [Security] ; This directive complements the above one. Any errors that occur during the ; execution of your script will be logged (typically, to your server's error log, ; but can be configured in several ways). Along with setting display_errors to off, ; this setup gives you the ability to fully understand what may have gone wrong, ; without exposing any sensitive information to remote users. ; - output_buffering = 4096 [Performance] ; Set a 4KB output buffer. Enabling output buffering typically results in less ; writes, and sometimes less packets sent on the wire, which can often lead to ; better performance. The gain this directive actually yields greatly depends ; on which Web server you're working with, and what kind of scripts you're using. ; - register_argc_argv = Off [Performance] ; Disables registration of the somewhat redundant $argv and $argc global ; variables. ; - magic_quotes_gpc = Off [Performance] ; Input data is no longer escaped with slashes so that it can be sent into ; SQL databases without further manipulation. Instead, you should use the ; database vendor specific escape string function on each input element you ; wish to send to a database. ; - variables_order = "GPCS" [Performance] ; The environment variables are not hashed into the $_ENV. To access ; environment variables, you can use getenv() instead. ; - error_reporting = E_ALL [Code Cleanliness, Security(?)] ; By default, PHP suppresses errors of type E_NOTICE. These error messages ; are emitted for non-critical errors, but that could be a symptom of a bigger ; problem. Most notably, this will cause error messages about the use ; of uninitialized variables to be displayed. ; - allow_call_time_pass_reference = Off [Code cleanliness] ; It's not possible to decide to force a variable to be passed by reference ; when calling a function. The PHP 4 style to do this is by making the ; function require the relevant argument by reference. ; - short_open_tag = Off [Portability] ; Using short tags is discouraged when developing code meant for redistribution ; since short tags may not be supported on the target server. ;;;;;;;;;;;;;;;;;;;; ; 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 = Off ; Allow ASP-style <% %> tags. asp_tags = Off ; The number of significant digits displayed in floating point numbers. precision = 14 ; 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 during 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 = 4096 ; 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. ;