php.ini 核心指令说明

该列表只包含可以配置 PHP 的核心 php.ini 指令。扩展的指令处理在各个扩展的文档页面分别列出和详细说明;比如,有关 session 指令可以在 sessions 页面找到。

注意:

当未加载 php.ini 时,使用以下列出的默认值;开发和生产环境的 php.ini 值可能会有所不同。

语言选项

语言和杂类配置选项
名字 默认 可修改范围 更新日志
short_open_tag "1" PHP_INI_PERDIR  
precision "14" PHP_INI_ALL  
serialize_precision "-1" PHP_INI_ALL 在 PHP 7.1.0 以前,默认值为 17。
disable_functions "" 仅为 PHP_INI_SYSTEM  
disable_classes "" 仅为 php.ini  
exit_on_timeout "" PHP_INI_ALL  
expose_php "1" 仅为 php.ini  
hard_timeout "2" PHP_INI_SYSTEM 从 PHP 7.1.0 起可用
zend.exception_ignore_args "0" PHP_INI_ALL 从 PHP 7.4.0 起可用
zend.multibyte "0" PHP_INI_ALL  
zend.script_encoding NULL PHP_INI_ALL  
zend.detect_unicode NULL PHP_INI_ALL  
zend.signal_check "0" PHP_INI_SYSTEM  
zend.assertions "1" 有限制的 PHP_INI_ALL  
zend.exception_string_param_max_len "15" PHP_INI_ALL 自 PHP 8.0.0 起可用。

这是配置指令的简短说明。

short_open_tag bool

告诉 PHP 是否允许 PHP 开放标签的缩写形式(<? ?>)。如果要 PHP 和 XML 结合使用,可以禁用此选项以便嵌入使用 <?xml ?>。否则还可以通过 PHP 来打印,例如:<?php echo '<?xml version="1.0"?>'; ?>。此外,如果禁用,必须使用 PHP 开放标签的完整形式(<?php ?>)。

注意:

本指令不会影响简写 <?=,因为它始终可用。

precision int
浮点数中显示有效数字的位数。-1 表示将使用增强算法来四舍五入此类数字。
serialize_precision int
序列化浮点数时存储的有效数字的位数。-1 表示将使用增强算法来四舍五入此类数字。
expose_php bool

确定是否向外界公开服务器上安装了 PHP,在 HTTP 标头中包含 PHP 版本号(例如:X-Powered-By: PHP/5.3.7)。

disable_functions string

本指令可用于禁止某些函数。接受逗号分隔的函数名列表作为参数。

此指令仅能禁用 内置函数。 不能影响用户自定义函数

本指令只能设置在 php.ini 中。例如不能将其设置在 httpd.conf 中。

disable_classes string
本指令允许禁用某些类。接受逗号分隔的类名列表作为参数。 本指令必须设置在 php.ini 中。例如不能将其设置在 httpd.conf 中。
zend.assertions int
当设置为 1 时,生成断言代码并执行(开发模式)。当设置为 0 时,将生成断言代码,但运行时会跳过(不执行)。当设置为 -1 时,不生成断言代码,使断言成本为零(生产模式)。

注意:

如果在生产模式下启动进程,则 zend.assertions 不能在运行时修改,因为未生成断言代码。

如果在开发模式下启动进程,则 zend.assertions 不能在运行时设置为 -1

zend.exception_string_param_max_len int
字符串化栈追踪中字符串函数参数的最大长度。必须介于 "0""1000000" 之间。
hard_timeout int

当命中 max_execution_time 中设置的超时的时候,PHP 运行时将会优雅的销毁资源。如果在这时卡住,硬超时将计时设置的秒数。当命中硬超时的时候,PHP 将异常退出。当设置为 0 时,硬超时始终不会激活。

当 PHP 因硬超时而停止时,它看起来像这样:

Fatal error: Maximum execution time of 30+2 seconds exceeded (terminated) in Unknown on line 0

zend.exception_ignore_args bool

从异常产生的栈中排除参数。

zend.multibyte bool

启用多字节编码的源文件解析。启用 zend.multibyte 是使用 SJIS、BIG5 等在多字节字符串数据中包含特殊字符的字符编码所必需的。ISO-8859-1 兼容的编码,如 UTF-8、EUC 等,则不需要这个选项。

启用 zend.multibyte 需要 mbstring 扩展可用。

zend.script_encoding string

除非在脚本顶部出现 declare(encoding=...) 指令,否则将会使用此值。当使用不兼容 ISO-8859-1 的编码时,必须同时使用 zend.multibyte 和 zend.script_encoding。

文本字符串将从 zend.script_encoding 直译为 mbstring.internal_encoding,就像调用了 mb_convert_encoding() 一样。

zend.detect_unicode bool

检查 BOM(Byte Order Mark,即字节顺序标记)并查看文件是否包含有效的多字节字符。此检测可以在处理 __halt_compiler() 执行。仅在 Zend 多字节模式下使用。

zend.signal_check bool

在关闭时检查替换的信号处理程序。

exit_on_timeout bool

这是 Apache1 mod_php-only 指令,如果 PHP 执行超时,会强制 Apache 子程序退出。这样的超时会导致 Apache1 内部的 longjmp() 调用,从而使一些扩展处于不一致的状态。通过终止进程,将会清除任何未完成的锁或内存。

资源限制

资源限制
名字 默认 可修改范围 更新日志
memory_limit "128M" PHP_INI_ALL  

这是配置指令的简短说明。

memory_limit int

设置了允许脚本分配的最大内存量,以字节为单位。这有助于防止写得不好的脚本吃掉服务器上所有可用的内存。请注意,如果不需要内存限制,请将此指令设置为 -1

当使用 int 时, 其值以字节来衡量。还可以使用在 FAQ 中描述的速记符。

请参阅:max_execution_time

性能调整

性能调整
名字 默认 可修改范围 更新日志
realpath_cache_size "4M" PHP_INI_SYSTEM PPHP 7.0.16 和 7.1.2 之前,默认值为 "16K"
realpath_cache_ttl "120" PHP_INI_SYSTEM  

注意:

启用 open_basedir 将会 禁用 realpath 缓存。

这是配置指令的简短说明。

realpath_cache_size int

设定 PHP 使用的 realpath 缓存的大小。在 PHP 打开很多文件的系统中,这个值应该增加,以优化执行文件操作的数量。

这里的大小表示存储的路径字符串的总字节数,加上与缓存条目相关的数据大小。这意味着,为了在缓存中存储更长的路径,缓存大小必须更大。这个值不直接控制可以缓存的不同路径的数量。

缓存输入数据所需的大小取决于操作系统。

realpath_cache_ttl int

缓存指定文件或目录的真实路径信息的持续时间(以秒为单位)。对于很少改变文件的系统,可以考虑增加该值。

数据处理

数据处理配置选项
名字 默认 可修改范围 更新日志
arg_separator.output "&" PHP_INI_ALL  
arg_separator.input "&" PHP_INI_PERDIR  
variables_order "EGPCS" PHP_INI_PERDIR  
request_order "" PHP_INI_PERDIR  
auto_globals_jit "1" PHP_INI_PERDIR  
register_argc_argv "1" PHP_INI_PERDIR  
enable_post_data_reading "1" PHP_INI_PERDIR  
post_max_size "8M" PHP_INI_PERDIR  
auto_prepend_file NULL PHP_INI_PERDIR  
auto_append_file NULL PHP_INI_PERDIR  
default_mimetype "text/html" PHP_INI_ALL  
default_charset "UTF-8" PHP_INI_ALL  
input_encoding "" PHP_INI_ALL  
output_encoding "" PHP_INI_ALL  
internal_encoding "" PHP_INI_ALL  

这是配置指令的简短说明。

arg_separator.output string

在 PHP 生成的 URL 中用来分隔参数的分隔符。

arg_separator.input string

PHP 用于将输入的 URL 解析为变量的分隔符列表。

注意:

本指令中的每一个字符都被视为分隔符!

variables_order string

设置 EGPCS(Environment、Get、Post、Cookie 和 Server)变量解析的顺序。例如,如果 variables_order 设置为 "SP",然后 PHP 将创建 superglobals $_SERVER$_POST,但不会创建 $_ENV$_GET$_COOKIE。设置为 "" 意味着不会设置 superglobals

警告

在 CGI 和 FastCGI SAPI 中,$_SERVER 也包含环境的值;S 始终等同于 ES,而不关心 E 在该指令中的位置。

注意:

$_REQUEST 的内容和顺序也受到此指令的影响。

request_order string

该指令描述了 PHP 将 GET、POST 和 Cookie 变量注册到 _REQUEST 数组中的顺序。注册是从左到右完成的,新值覆盖旧值。

如果未设置此指令,则 variables_order 用于 $_REQUEST 内容。

请注意,出于安全考虑,默认分发的 php.ini 文件不包含 cookie 的 'C'

auto_globals_jit bool

启用后,SERVER、REQUEST 和 ENV 变量在首次使用时(即时)创建,而不是在脚本启动时创建。如果这些变量未在脚本中使用,启用此指令将提高性能。

警告

在编译期间检查 SERVER、REQUEST 和 ENV 变量的使用,因此通过可变变量使用它们将不会使其初始化。

register_argc_argv bool
告诉 PHP 是否声明 argv & argc 变量(将包含 GET 信息)。 另请参阅命令行
enable_post_data_reading bool
禁用这个选项会导致不会填充 $_POST$_FILES。读取 postdata 的唯一方法是通过 php://input 流封装协议。这对于代理请求或以高效内存的方式处理 POST 数据很有用。
post_max_size int
设置允许 post 数据的最大大小。此设置也会影响文件上传。要上传大文件,此值必须大于 upload_max_filesize 一般来说,memory_limit 应该大于 post_max_size 当使用 int 时, 其值以字节来衡量。还可以使用在 FAQ 中描述的速记符。 如果 post 数据的大小大于 post_max_size,则 $_POST$_FILES 超全局变量为空。这可以通过多种方式进行跟踪,例如通过将 $_GET 变量传递给处理数据的脚本,即 <form action="edit.php?processed=1">,然后检查是否设置了 $_GET['processed']

注意:

PHP 允许使用字节值的快捷方式,包括 K(千)、M(兆)和 G(千兆)。如果使用其中任何一个,PHP 将自动进行转换。注意不要超过 32 位有符号整数限制(如果使用的是 32 位版本),因为这会导致脚本失败。

post_max_size 变更日志
版本 说明
5.3.4 post_max_size = 0 will not disable the limit when the content type is application/x-www-form-urlencoded or is not registered with PHP.
5.3.2 , 5.2.12 Allow unlimited post size by setting post_max_size to 0.

auto_prepend_file string

指定在主文件之前自动解析的文件名。included 该文件像是用 require 函数调用的一样,因此使用了 include_path

特殊值 none 禁用 auto-prepending。

auto_append_file string

指定在主文件之后自动解析的文件名。included 该文件像是用 require 函数调用的一样,因此使用了 include_path

特殊值 none 禁用 auto-prepending。

注意: 如果脚本以 exit() 终止,则不会发生 auto-append。

default_mimetype string

默认情况下,PHP 将使用 Content-Type 标头输出媒体类型。只需将其设置为空即可禁用。

PHP 内置默认媒体类型设置为 text/html。

default_charset string

“UTF-8”是默认值,如果省略 encoding 参数,它的值将用作 htmlentities()html_entity_decode()htmlspecialchars() 的默认字符编码。 如果未设置 iconv.input_encodingiconv.output_encodingiconv.internal_encoding 配置选项,则 default_charset 的值也将用于设置 iconv 函数的默认字符集,如果 mbstring.http_input mbstring.http_output mbstring.internal_encoding 配置选项未设置,则也可用于 mbstring 函数。

如果标头未通过调用 header() 覆盖,则所有版本的 PHP 都将使用此值作为 PHP 发送的默认 Content-Type 报头中的字符集。

不推荐设置 default_charset 为空字符串。

input_encoding string

此设置用于多字节模块,例如 mbstring 和 iconv。 默认为空。

output_encoding string

此设置用于多字节模块,例如 mbstring 和 iconv。 默认为空。

internal_encoding string

此设置用于多字节模块,例如 mbstring 和 iconv。 默认为空。 如果为空,则使用 default_charset

路径和目录

路径和目录配置项
名字 默认 可修改范围 更新日志
include_path ".;/path/to/php/pear" PHP_INI_ALL  
open_basedir NULL PHP_INI_ALL  
doc_root NULL PHP_INI_SYSTEM  
user_dir NULL PHP_INI_SYSTEM  
user_ini.cache_ttl "300" PHP_INI_SYSTEM  
user_ini.filename ".user.ini" PHP_INI_SYSTEM  
extension_dir "/path/to/php" PHP_INI_SYSTEM  
extension NULL php.ini only  
zend_extension NULL php.ini only  
cgi.check_shebang_line "1" PHP_INI_SYSTEM  
cgi.discard_path "0" PHP_INI_SYSTEM  
cgi.fix_pathinfo "1" PHP_INI_SYSTEM  
cgi.force_redirect "1" PHP_INI_SYSTEM  
cgi.nph "0" PHP_INI_SYSTEM  
cgi.redirect_status_env NULL PHP_INI_SYSTEM  
cgi.rfc2616_headers "0" PHP_INI_ALL  
fastcgi.impersonate "0" PHP_INI_SYSTEM  
fastcgi.logging "1" PHP_INI_SYSTEM  

这是配置指令的简短说明。

include_path string

指定 requireincludefopen()file()readfile()file_get_contents() 函数在其中查找文件的目录列表,格式类似于系统的 PATH 环境变量:目录列表,在 Unix 中使用冒号分隔,在 Windows 中使用分号分隔。

PHP considers each entry in the include path separately when looking for files to include. It will check the first path, and if it doesn't find it, check the next path, until it either locates the included file or returns with an E_WARNING or an E_ERROR. You may modify or set your include path at runtime using set_include_path().

示例 #1 Unix include_path

include_path=".:/php/includes"

示例 #2 Windows include_path

include_path=".;c:\php\includes"

Using a . in the include path allows for relative includes as it means the current directory. However, it is more efficient to explicitly use include './file' than having PHP always check the current directory for every include.

注意:

ENV variables are also accessible in .ini files. As such it is possible to reference the home directory using ${LOGIN} and ${USER}.

Environment variables may vary between Server APIs as those environments may be different.

示例 #3 Unix include_path using ${USER} env variable

include_path = ".:${USER}/pear/php"

open_basedir string

Limit the files that can be accessed by PHP to the specified directory-tree, including the file itself.

When a script tries to access the filesystem, for example using include, or fopen(), the location of the file is checked. When the file is outside the specified directory-tree, PHP will refuse to access it. All symbolic links are resolved, so it's not possible to avoid this restriction with a symlink. If the file doesn't exist then the symlink couldn't be resolved and the filename is compared to (a resolved) open_basedir.

open_basedir can affect more than just filesystem functions; for example if MySQL is configured to use mysqlnd drivers, LOAD DATA INFILE will be affected by open_basedir. Much of the extended functionality of PHP uses open_basedir in this way.

The special value . indicates that the working directory of the script will be used as the base-directory. This is, however, a little dangerous as the working directory of the script can easily be changed with chdir().

In httpd.conf, open_basedir can be turned off (e.g. for some virtual hosts) the same way as any other configuration directive with "php_admin_value open_basedir none".

Under Windows, separate the directories with a semicolon. On all other systems, separate the directories with a colon. As an Apache module, open_basedir paths from parent directories are now automatically inherited.

The restriction specified with open_basedir is a directory name, not a prefix.

The default is to allow all files to be opened.

注意:

open_basedir can be tightened at run-time. This means that if open_basedir is set to /www/ in php.ini a script can tighten the configuration to /www/tmp/ at run-time with ini_set(). When listing several directories, you can use the PATH_SEPARATOR constant as a separator regardless of the operating system.

注意:

Using open_basedir will set realpath_cache_size to 0 and thus disable the realpath cache.

警告

open_basedir 只是额外的安全保障,并不全面,因此在需要安全性时并不能依赖它。

doc_root string

PHP's "root directory" on the server. Only used if non-empty. 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). The alternative is to use the cgi.force_redirect configuration below.

user_ini.cache_ttl int

user_ini.filename string

user_dir string

The base name of the directory used on a user's home directory for PHP files, for example public_html .

extension_dir string

PHP 寻找可动态加载扩展的目录。建议指定绝对路径。参阅 enable_dldl()

extension string

Which dynamically loadable extensions to load when PHP starts up.

zend_extension string

Name of dynamically loadable Zend extension (for example XDebug) to load when PHP starts up.

cgi.check_shebang_line bool

Controls whether CGI PHP checks for line starting with #! (shebang) at the top of the running script. This line might be needed if the script support running both as stand-alone script and via PHP CGI. PHP in CGI mode skips this line and ignores its content if this directive is turned on.

cgi.discard_path bool

If this is enabled, the PHP CGI binary can safely be placed outside of the web tree and people will not be able to circumvent .htaccess security.

cgi.fix_pathinfo bool

Provides real PATH_INFO/ PATH_TRANSLATED support for CGI. PHP's previous behaviour was to set PATH_TRANSLATED to SCRIPT_FILENAME, and to not grok what PATH_INFO is. For more information on PATH_INFO, see the CGI specs. Setting this to 1 will cause PHP CGI to fix its paths to conform to the spec. A setting of zero causes PHP to behave as before. It is turned on by default. You should fix your scripts to use SCRIPT_FILENAME rather than PATH_TRANSLATED.

cgi.force_redirect bool

cgi.force_redirect is necessary to provide security running PHP as a CGI under most web servers. Left undefined, PHP turns this on by default. You can turn it off at your own risk.

注意:

Windows Users: When using IIS this option must be turned off. For OmniHTTPD or Xitami the same applies.

cgi.nph bool

If cgi.nph is enabled it will force cgi to always sent Status: 200 with every request.

cgi.redirect_status_env string

If cgi.force_redirect is turned on, and you are not running under Apache or Netscape (iPlanet) web servers, you may need to set an environment variable name that PHP will look for to know it is OK to continue execution.

注意:

Setting this variable may cause security issues, know what you are doing first.

cgi.rfc2616_headers int

Tells PHP what type of headers to use when sending HTTP response code. If it's set to 0, PHP sends a » RFC 3875 "Status:" header that is supported by Apache and other web servers. When this option is set to 1, PHP will send » RFC 2616 compliant headers.

If this option is enabled, and you are running PHP in a CGI environment (e.g. PHP-FPM) you should not use standard RFC 2616 style HTTP status response headers, you should instead use their RFC 3875 equivalent e.g. instead of header("HTTP/1.0 404 Not found"); you should use header("Status: 404 Not Found");

Leave it set to 0 unless you know what you're doing.

fastcgi.impersonate string

FastCGI under IIS (on WINNT based OS) supports the ability to impersonate security tokens of the calling client. This allows IIS to define the security context that the request runs under. mod_fastcgi under Apache does not currently support this feature (03/17/2002) Set to 1 if running under IIS. Default is zero.

fastcgi.logging bool

Turns on SAPI logging when using FastCGI. Default is to enable logging.

文件上传

文件上传配置项
名字 默认 可修改范围 更新日志
file_uploads "1" PHP_INI_SYSTEM  
upload_tmp_dir NULL PHP_INI_SYSTEM  
max_input_nesting_level 64 PHP_INI_PERDIR  
max_input_vars 1000 PHP_INI_PERDIR  
upload_max_filesize "2M" PHP_INI_PERDIR  
max_file_uploads 20 PHP_INI_PERDIR  

这是配置指令的简短说明。

file_uploads bool

是否允许 HTTP 文件上传。参阅 upload_max_filesizeupload_tmp_dirpost_max_size 指令。

upload_tmp_dir string

上传文件时用来存放文件的临时目录。必须允许运行 PHP 的任何用户写入。如果未指定,PHP 将使用系统默认值。

如果此处指定的目录不可写,PHP 回退到系统默认临时目录。如果打开 open_basedir,然后允许系统临时目录才可以成功上传。

upload_max_filesize int

上传文件的最大大小。

post_max_size 必须大于此值。

当使用 int 时, 其值以字节来衡量。还可以使用在 FAQ 中描述的速记符。
max_file_uploads int

允许同时上传的最大文件数。提交时留空的上传字段不计入此限制。

常规 SQL

常规 SQL 配置项
名字 默认 可修改范围 更新日志
sql.safe_mode "0" PHP_INI_SYSTEM 自 PHP 7.2.0 起移除

这是配置指令的简短说明。

sql.safe_mode bool

If turned on, database connection functions that specify default values will use those values in place of any user-supplied arguments. For details on the default values, see the documentation for the relevant connection functions.

警告

此功能自 PHP 7.2.0 起移除

Windows 专用

Windows 专用配置选项
名字 默认 可修改范围 更新日志
windows.show_crt_warning "0" PHP_INI_ALL  

这是配置指令的简短说明。

windows.show_crt_warning bool

该指令在启用时显示 Windows CRT 警告。

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User Contributed Notes 20 notes

up
2
andre dot wetter at myelco dot ch
1 year ago
If you use Microsoft IIS Windows and want to use open_basedir restrictions with multiple dirs you have to set them into single quotes in the main config xml file of IIS (C:\Windows\System32\inetsrv\config\applicationHost.config). Works fine in IIS 10.

Multiple files with single quotes and ; for windows:
"C:\php\php-cgi.exe|-d open_basedir='C:\Windows\Temp\;D:\mywebsite1\'"

Only one dir works fine without single quotes:
"C:\php\php-cgi.exe|-d open_basedir=D:\mywebsite1\"

In my main config xml file of IIS there are 2 nodes to set per website and the definitions have to be equal:
configuration\Location\system.webServer\handlers\add
configuration\system.webServer\fastCgi
up
21
csg at DEL_THISdiatom dot de
17 years ago
Starting with PHP 4.4.0 (at least PHP version 4.3.10 did have old, documented behaviour) interpretation of value of "session.save_path" did change in conjunction with "save_mode" and "open_basedir" enabled.

Documented ( http://de.php.net/manual/en/ref.session.php#ini.session.save-path ):
  Values of "session.save_path" should or may be  **without**  ending slash.
  For instance:
<?php
 
// Valid only  *before* PHP 4.4.0:
 
ini_set( "session.save_path", "/var/httpd/kunde/phptmp" );
?> will mean:
  The directory "/var/httpd/kunde/phptmp/" will be used to write data and therefore must be writable by the web server.

Starting with PHP 4.4.0 the server complains that "/var/httpd/kunde/" is not writable.
Solution: Add an ending slash in call of ini_set (or probably whereever you set "session.save_path"), e.g.:
<?php
 
// Note the slash on ".....phptmp/":
 
ini_set( "session.save_path", "/var/httpd/kunde/phptmp/" );
?>

Hope, that does help someone.
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3
Simone Pellegatta
2 years ago
Be careful while using auto_prepend_file.

When the custom exception handler, set by set_exception_handler(), handles an uncaught exception, it interrupts the execution of every script.

If the script with the unhandled exception has been automatically prepended or included by an automatically prepended script, however, the main script will continue running anyway.

This could cause several issues: when we think that throwing an exception would automatically interrupt the current application, a whole chunk of code is going to run anyway.
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5
luisdev
3 years ago
https://haydenjames.io/understanding-php-memory_limit/ explains the memory_limit setting nicely.
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2
Anton Bannikov
2 years ago
I had a problem with 'open_basedir =' string in php.ini. This string was writtren in VirtualHost Directory directive of Apache2 and successfully rewrote the same php.ini setting! It happened with VestaCP, but I think, it's a common way. Goog luck!
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3
rlammers at linuxmail dot org
12 years ago
This is a possible solution for a problem which seems to be a php-ini-problem but is not.

If a $_POST is used with large fields e.g. textarea's with more than 120kb characters php returns a blank screen, even if the max_post_size is 8M.

This problem may be caused by an apache-module SecFilter.

Adding the following lines to the .htaccess solves the problem.
SecFilterEngine Off
SecFilterScanPOST Off

I know this is not a php-issue, but i'm still posting it here since it looks like it is a php-problem and I did not find any sites or forums offering this solution.
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-1
amolitor at molitor-design dot com
13 years ago
Amusingly, the include_path logically includes the current directory of the running file as the last entry all the time anyways, so part of the business about shoving "." into the include_path is spurious -- it's "there" on the end all the time, at least in the 5.2.12 source (see main/fopen_wrappers.c around line 503).

This one had me goin' for a while.
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-2
dougal at gunters dot org
7 years ago
It appears that if you use both the 'include_path' directives and 'open_basedir', that file searches will hit the include path *first*, before local files. But if 'open_basedir' is not in use, then local files are found first. For example, suppose you have code in '/var/www/myfile.php' which does:

<?php
 
require_once('config.php');
?>

Further, assume that there is a local file '/var/www/config.php', and there is also a file '/var/local/php/config.php'.

Next, if your php.ini has:

  include_path = /var/local/php/

Normally, this would look for '/var/www/config.php' first, and if not found, then it would try '/var/local/php/config.php'.

But if you also have this in php.ini:

  open_basedir = /var/www/:/var/local/php/

Then the require would reverse the order of the search, and load '/var/local/php/config.php', even when the local 'config.php' file exists.

Furthermore, if include_path contains directories not in open_basedir, you can end up with a fatal error. For example, change the directive to:

  open_basedir = /var/www/:/var/local/includes/php/

Now the require will first find '/var/local/php/config.php' from the include_path, try to include it, but be unable to because of the open_basedir restrictions.
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-2
fernandobasso dot br at gmail dot com
6 years ago
This might help in case someone happens to maintain old applications with a charset other than utf-8.

According to the docs, you can override the default charset if you use `header()`.

Suppose php.ini sets the default_charset to "UTF-8", but you need a legacy charset, like ISO-8859-1.

Still,

<?php header('Content-Type: text/html; Charset=ISO-8859-1'); ?>

would not override the charset, just add it as well and the result
was a response header like (note the two charsets):

    Content-Type:"text/html; Charset=ISO-8859-1;charset=UTF-8"

I found it strange the default one as `charset` with a lowercase `c`
as opposed to my custom charset with an uppercase `C`.

What solved was to _override_ the charset using all lowercase letters
as well for the word “charset”:

<?php header('content-type: text/html; charset=ISO-8859-1'); ?>

Then, the double charset from the response headers disappeared, and only the single, custom charset remained.
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-2
leo at korfu dot cz
16 years ago
"If the size of post data is greater than post_max_size..."

It seems that a more elegant way is comparison between post_max_size and $_SERVER['CONTENT_LENGTH']. Please note that the latter includes not only size of uploaded file plus post data but also multipart sequences. Leo
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-3
mrok at mrok dot com
14 years ago
Note that on some Unix systems (i.e. PHP 5.1.6 on Centos 5.2) include_path in php.ini should NOT be quoted.

For example, instead of

include_path='.:/usr/share/php'

use

include_path=.:/usr/share/php

Using quotes does not cause any error message, but all of your require_once() directives will fail (indicating that file could not be opened) - unless full path to target file is provided.
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-5
txyoji at yahoo dot com
9 years ago
If you enable "open_basedir" option, it will disable the realpath_cache. This can be a significant performance hit.

https://bugs.php.net/bug.php?id=53263
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-5
AntonioK
12 years ago
Note that there is no way to disable eval() work by using disable_functions directive, because eval() is a language construct and not a function.

Many people advise to disable such potentially-insecure functions like system(), exec(), passthru(), eval() and so on in php.ini when not running in safe mode, but eval() would still work even it listed in disable_functions.
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-3
alaa morad
4 years ago
add enctype="multipart/form-data" to your <form> tag or it will not upload any file even if file_uploads=on
ex:
<form method="POST" action="upload. php" enctype="multipart/form-data">
// form contents
</form>
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-6
iko at vision dot sk
10 years ago
auto_globals_jit setting is also affecting $_REQUEST superglobal in 5.3 It is not explicitly stated in documentation.
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-4
diamondeagle at webmail dot co dot za
3 years ago
Note regarding the upload_tmp_dir setting and UNC Paths:

When using PHP on Windows OS and IIS FastCGI, if you need to use a UNC path to a folder on a network drive for the upload_tmp_dir setting then you must use three \ characters at the front of the UNC path.

Windows and PHP use the first slash as an escape character, so if you only use two slashes then it passes a UNC path with just one backslash. That is not valid for UNC paths and you many experience problems when uploading files, such as errors saying that "PHP is missing a temporary folder".

Correct:
upload_tmp_dir = "\\\path\to\your\folder"

Incorrect:
upload_tmp_dir = "\\path\to\your\folder"
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-9
kghbln
11 years ago
Adding multiple directories to open_basedir:

open_basedir = "/var/www/htdocs/:/var/www/tmp/" adds both paths /var/www/htdocs/ and /var/www/tmp/. Do not forget the trailing slash, otherwise the last directory will be considered as a prefix (< 5.3.4).

On Windows you use ; as the seperator.
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-11
Adam
6 years ago
Remember that `open_basedir` restriction does not affect exec functions. As long as you do not disable exec functions (see `disable_functions`, users will be able to use `exec("/bin/cat [...]")` to access sensitive world readable files.
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-19
michael dot buergi at gmx dot net
9 years ago
the ini-setting "detect_unicode" is indeed "zend.detect_unicode" (according to the phpinfo of my 5.4.4)
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-30
abc500x500 at gmail dot com
5 years ago
Please illuminate this:
memory_limit=128mb meaning which?

1-per script only then if in a moment 1000 user request php script maximum only 128mb of server ram use6 by script.
2-per script + per user if in a moment 1000 user request a php script about 1000*128mb=128gb ram use by script.
Thanks
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