This list includes the core php.ini directives you can set to configure your PHP setup. Directives handled by extensions are listed and detailed at the extension documentation pages respectively; Information on the session directives for example can be found at the sessions page.
Name | Default | Changeable | Changelog |
---|---|---|---|
async_send | "0" | PHP_INI_ALL |
Name | Default | Changeable | Changelog |
---|---|---|---|
short_open_tag | "1" | PHP_INI_ALL | PHP_INI_ALL in PHP 4.0.0. PHP_INI_PERDIR in PHP < 5.3.0 |
asp_tags | "0" | PHP_INI_PERDIR | PHP_INI_ALL in PHP 4.0.0. |
precision | "14" | PHP_INI_ALL | |
serialize_precision | "17" | PHP_INI_ALL | Available since PHP 4.3.2. Until PHP 5.3.5, the default value was 100. |
y2k_compliance | "1" | PHP_INI_ALL | Removed in PHP 5.4.0. |
allow_call_time_pass_reference | "1" | PHP_INI_PERDIR | PHP_INI_ALL in PHP 4.0.0. Removed in PHP 5.4.0. |
disable_functions | "" | php.ini only | Available since PHP 4.0.1. |
disable_classes | "" | php.ini only | Available since PHP 4.3.2. |
exit_on_timeout | "" | PHP_INI_ALL | Available since PHP 5.3.0. |
expose_php | "1" | php.ini only | |
zend.multibyte | "0" | PHP_INI_ALL | Available since PHP 5.4.0 |
zend.script_encoding | NULL | PHP_INI_ALL | Available since PHP 5.4.0 |
zend.signal_check | "0" | PHP_INI_SYSTEM | Available since PHP 5.4.0 |
zend.ze1_compatibility_mode | "0" | PHP_INI_ALL | Available since PHP 5.0.0. Removed in PHP 5.3.0 |
detect_unicode | "1" | PHP_INI_ALL | Available since PHP 5.1.0. This deprecated feature will certainly be removed in the future. |
Here's a short explanation of the configuration directives.
short_open_tag
boolean
Tells PHP whether the short form (<? ?>
)
of PHP's open tag should be allowed. If you want to use PHP in
combination with XML, you can disable this option in order to
use <?xml ?>
inline. Otherwise, you
can print it with PHP, for example: <?php echo '<?xml
version="1.0"?>'; ?>
. Also, if disabled, you must use the
long form of the PHP open tag (<?php ?>
).
Note:
This directive also affected the shorthand
<?=
before PHP 5.4.0, which is identical to<? echo
. Use of this shortcut requiredshort_open_tag
to be on. Since PHP 5.4.0,<?=
is always available.
precision
integer
serialize_precision
integer
y2k_compliance
boolean
allow_call_time_pass_reference
boolean
Whether to warn when arguments are passed by reference at function call time. 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).
Passing arguments by reference at function call time was deprecated for code-cleanliness reasons. A function can modify its arguments in an undocumented way if it didn't declare that the argument shall be passed by reference. To prevent side-effects it's better to specify which arguments are passed by reference in the function declaration only.
See also References Explained.
Version | Description |
---|---|
5.4.0 | Removed from PHP. |
5.3.0 |
Emits an E_DEPRECATED level error.
|
5.0.0 |
Deprecated, and generates an E_COMPILE_WARNING level error.
|
expose_php
boolean
Exposes to the world that PHP is installed on the server, which includes the PHP version within the HTTP header (e.g., X-Powered-By: PHP/5.3.7). The PHP logo guids are also exposed, thus appending them to the URL of a PHP enabled site will display the appropriate logo (e.g., » http://www.php.net/?=PHPE9568F34-D428-11d2-A769-00AA001ACF42). This also affects the output of phpinfo(), as when disabled, the PHP logo and credits information will not be displayed.
See also php_logo_guid() and phpcredits().
disable_functions
string
This directive allows you to disable certain functions for security reasons. It takes on a comma-delimited list of function names. disable_functions is not affected by Safe Mode.
Only internal functions can be disabled using this directive. User-defined functions are unaffected.
This directive must be set in php.ini For example, you cannot set this in httpd.conf.
disable_classes
string
Note: Availability note
This directive became available in PHP 4.3.2
zend.ze1_compatibility_mode
boolean
Enable compatibility mode with Zend Engine 1 (PHP 4). It affects
the cloning, casting (objects with no properties cast to FALSE
or 0), and comparing of objects.
In this mode, objects are passed by value instead of reference by
default.
See also the section titled Migrating from PHP 4 to PHP 5.
This feature has been DEPRECATED and REMOVED as of PHP 5.3.0.
zend.multibyte
boolean
Enables parsing of source files in multibyte encodings.
zend.script_encoding
string
This value will be used unless a declare(encoding=...) directive appears at the top of the script.
zend.signal_check
boolean
To check for replaced signal handlers on shutdown.
detect_unicode
boolean
Check for BOM (Byte Order Mark) and see if the file contains valid multibyte characters. This detection is performed before processing of __halt_compiler(). Available only in Zend Multibyte mode.
exit_on_timeout
boolean
This is an Apache1 mod_php-only directive that forces an Apache child to exit if a PHP execution timeout occurred. Such a timeout causes an internal longjmp() call in Apache1 which can leave some extensions in an inconsistent state. By terminating the process any outstanding locks or memory will be cleaned up.
Name | Default | Changeable | Changelog |
---|---|---|---|
memory_limit | "128M" | PHP_INI_ALL | "8M" before PHP 5.2.0, "16M" in PHP 5.2.0 |
Here's a short explanation of the configuration directives.
memory_limit
integer
This sets the maximum amount of memory in bytes that a script is allowed to allocate. This helps prevent poorly written scripts for eating up all available memory on a server. Note that to have no memory limit, set this directive to -1.
Prior to PHP 5.2.1, in order to use this directive it had to be enabled at compile time by using --enable-memory-limit in the configure line. This compile-time flag was also required to define the functions memory_get_usage() and memory_get_peak_usage() prior to 5.2.1.
When an integer is used, the value is measured in bytes. Shorthand notation, as described in this FAQ, may also be used.See also: max_execution_time.
Name | Default | Changeable | Changelog |
---|---|---|---|
realpath_cache_size | "16K" | PHP_INI_SYSTEM | Available since PHP 5.1.0. |
realpath_cache_ttl | "120" | PHP_INI_SYSTEM | Available since PHP 5.1.0. |
Here's a short explanation of the configuration directives.
realpath_cache_size
integer
Determines the size of the realpath cache to be used by PHP. This value should be increased on systems where PHP opens many files, to reflect the quantity of the file operations performed.
realpath_cache_ttl
integer
Duration of time (in seconds) for which to cache realpath information for a given file or directory. For systems with rarely changing files, consider increasing the value.
Name | Default | Changeable | Changelog |
---|---|---|---|
track_vars | "On" | PHP_INI_?? | |
arg_separator.output | "&" | PHP_INI_ALL | Available since PHP 4.0.5. |
arg_separator.input | "&" | PHP_INI_PERDIR | Available since PHP 4.0.5. |
variables_order | "EGPCS" | PHP_INI_PERDIR | PHP_INI_ALL in PHP <= 5.0.5. |
request_order | "" | PHP_INI_PERDIR | Available since PHP 5.3.0 |
auto_globals_jit | "1" | PHP_INI_PERDIR | Available since PHP 5.0.0. |
register_globals | "0" | PHP_INI_PERDIR | PHP_INI_ALL in PHP <= 4.2.3. Removed in PHP 5.4.0. |
register_argc_argv | "1" | PHP_INI_PERDIR | PHP_INI_ALL in PHP <= 4.2.3. |
register_long_arrays | "1" | PHP_INI_PERDIR | Available since PHP 5.0.0. Deprecated in PHP 5.3.0. Removed in PHP 5.4.0. |
post_max_size | "8M" | PHP_INI_PERDIR | PHP_INI_SYSTEM in PHP <= 4.2.3. Available since PHP 4.0.3. |
gpc_order | "GPC" | PHP_INI_ALL | |
auto_prepend_file | NULL | PHP_INI_PERDIR | PHP_INI_ALL in PHP <= 4.2.3. |
auto_append_file | NULL | PHP_INI_PERDIR | PHP_INI_ALL in PHP <= 4.2.3. |
default_mimetype | "text/html" | PHP_INI_ALL | |
default_charset | "" | PHP_INI_ALL | |
always_populate_raw_post_data | "0" | PHP_INI_PERDIR | PHP_INI_ALL in PHP <= 4.2.3. Available since PHP 4.1.0. |
allow_webdav_methods | "0" | PHP_INI_PERDIR |
Here's a short explanation of the configuration directives.
track_vars
boolean
If enabled, then Environment, GET, POST, Cookie, and Server variables can be found in the global associative arrays $_ENV, $_GET, $_POST, $_COOKIE, and $_SERVER.
Note that as of PHP 4.0.3, track_vars
is always turned on.
arg_separator.output
string
The separator used in PHP generated URLs to separate arguments.
arg_separator.input
string
List of separator(s) used by PHP to parse input URLs into variables.
Note:
Every character in this directive is considered as separator!
variables_order
string
Sets the order of the EGPCS (Environment, Get, Post, Cookie, and Server) variable parsing. For example, if variables_order is set to "SP" then PHP will create the superglobals $_SERVER and $_POST, but not create $_ENV, $_GET, and $_COOKIE. Setting to "" means no superglobals will be set.
If the deprecated register_globals directive is on, then variables_order also configures the order the ENV, GET, POST, COOKIE and SERVER variables are populated in global scope. So for example if variables_order is set to "EGPCS", register_globals is enabled, and both $_GET['action'] and $_POST['action'] are set, then $action will contain the value of $_POST['action'] as P comes after G in our example directive value.
In both the CGI and FastCGI SAPIs, $_SERVER is also populated by values from the environment; S is always equivalent to ES regardless of the placement of E elsewhere in this directive.
Note:
The content and order of $_REQUEST is also affected by this directive.
request_order
string
This directive describes the order in which PHP registers GET, POST and Cookie variables into the _REQUEST array. Registration is done from left to right, newer values override older values.
If this directive is not set, variables_order is used for $_REQUEST contents.
Note that the default distribution php.ini files does not contain the 'C' for cookies, due to security concerns.
auto_globals_jit
boolean
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. Since PHP 5.1.3 it is not necessary to have register_argc_argv disabled.
Usage of SERVER and ENV variables is checked during the compile time so using them through e.g. variable variables will not cause their initialization.
register_globals
boolean
Whether or not to register the EGPCS (Environment, GET, POST, Cookie, Server) variables as global variables.
As of » PHP 4.2.0, this directive defaults to off.
Please read the security chapter on Using register_globals for related information.
Please note that register_globals
cannot be set at runtime (ini_set()). Although, you can
use .htaccess if your host allows it as described
above. An example .htaccess entry:
php_flag register_globals off
.
Note:
register_globals
is affected by the variables_order directive.
This feature has been DEPRECATED as of PHP 5.3.0 and REMOVED as of PHP 5.4.0.
register_argc_argv
boolean
register_long_arrays
boolean
This feature has been DEPRECATED as of PHP 5.3.0 and REMOVED as of PHP 5.4.0.
enable_post_data_reading
boolean
post_max_size
integer
post_max_size
.
When an integer is used, the
value is measured in bytes. Shorthand notation, as described
in this FAQ, may also be used.
If the size of post data is greater than post_max_size, the
$_POST and $_FILES
superglobals
are empty. This can be tracked in various ways, e.g. by passing the
$_GET variable to the script processing the data,
i.e. <form action="edit.php?processed=1">,
and then checking if $_GET['processed'] is set.
Note:
PHP allows shortcuts for bit values, including K (kilo), M (mega) and G (giga). PHP will do the conversions automatically if you use any of these. Be careful not to exceed the 32 bit signed integer limit (if you're using 32bit versions) as it will cause your script to fail.
gpc_order
string
Set the order of GET/POST/COOKIE variable parsing. The default setting of this directive is "GPC". Setting this to "GP", for example, will cause PHP to completely ignore cookies and to overwrite any GET method variables with POST-method variables of the same name.
Note:
This option is not available in PHP 4. Use variables_order instead.
auto_prepend_file
string
Specifies the name of a file that is automatically parsed before the main file. The file is included as if it was called with the require function, so include_path is used.
The special value none disables auto-prepending.
auto_append_file
string
Specifies the name of a file that is automatically parsed after the main file. The file is included as if it was called with the require function, so include_path is used.
The special value none disables auto-appending.
Note: If the script is terminated with exit(), auto-append will not occur.
default_mimetype
string
default_charset
string
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.
always_populate_raw_post_data
boolean
Always populate the $HTTP_RAW_POST_DATA containing the raw POST data. Otherwise, the variable is populated only with unrecognized MIME type of the data. However, the preferred method for accessing the raw POST data is php://input. $HTTP_RAW_POST_DATA is not available with enctype="multipart/form-data".
allow_webdav_methods
boolean
Allow handling of WebDAV http requests within PHP scripts (eg. PROPFIND, PROPPATCH, MOVE, COPY, etc.). This directive does not exist as of PHP 4.3.2. If you want to get the post data of those requests, you have to set always_populate_raw_post_data as well.
See also: magic_quotes_gpc, magic_quotes_runtime, and magic_quotes_sybase.
Name | Default | Changeable | Changelog |
---|---|---|---|
include_path | ".;/path/to/php/pear" | PHP_INI_ALL | |
open_basedir | NULL | PHP_INI_ALL | PHP_INI_SYSTEM in PHP < 5.3.0 |
doc_root | NULL | PHP_INI_SYSTEM | |
user_dir | NULL | PHP_INI_SYSTEM | |
extension_dir | "/path/to/php" | PHP_INI_SYSTEM | |
extension | NULL | php.ini only | |
zend_extension | NULL | php.ini only | |
zend_extension_debug | NULL | php.ini only | Available before PHP 5.3.0. |
zend_extension_debug_ts | NULL | php.ini only | Available before PHP 5.3.0. |
zend_extension_ts | NULL | php.ini only | Available before PHP 5.3.0. |
cgi.check_shebang_line | "1" | PHP_INI_SYSTEM | Available since PHP 5.2.0. |
cgi.fix_pathinfo | "1" | PHP_INI_SYSTEM | Available since PHP 4.3.0. PHP_INI_ALL prior to PHP 5.2.1. |
cgi.force_redirect | "1" | PHP_INI_SYSTEM | Available since PHP 4.2.0. PHP_INI_ALL prior to PHP 5.2.1. |
cgi.redirect_status_env | NULL | PHP_INI_SYSTEM | Available since PHP 4.2.0. PHP_INI_ALL prior to PHP 5.2.1. |
cgi.rfc2616_headers | "0" | PHP_INI_ALL | Available since PHP 4.3.0. |
fastcgi.impersonate | "0" | PHP_INI_SYSTEM | Available since PHP 4.3.0. PHP_INI_ALL prior to PHP 5.2.1. |
fastcgi.logging | "1" | PHP_INI_SYSTEM | Available since PHP 4.3.0. PHP_INI_ALL prior to PHP 5.2.1. |
Here's a short explanation of the configuration directives.
include_path
string
Specifies a list of directories where the require, include, fopen(), file(), readfile() and file_get_contents() functions look for files. The format is like the system's PATH environment variable: a list of directories separated with a colon in Unix or semicolon in Windows.
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 a warning or an error. You may modify or set your include path at runtime using set_include_path().
Example #1 Unix include_path
include_path=".:/php/includes"
Example #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.
open_basedir
string
Limit the files that can be opened by PHP to the specified directory-tree, including the file itself. This directive is NOT affected by whether Safe Mode is turned On or Off.
When a script tries to open a file with, for example, fopen() or gzopen(), the location of the file is checked. When the file is outside the specified directory-tree, PHP will refuse to open 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 .
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 since PHP 5.2.16 and 5.3.4. Previous versions used it as a prefix. This means that "open_basedir = /dir/incl" also allowed access to "/dir/include" and "/dir/incls" if they exist. When you want to restrict access to only the specified directory, end with a slash. For example: open_basedir = /dir/incl/
The default is to allow all files to be opened.
Note:
As of PHP 5.3.0 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.
doc_root
string
PHP's "root directory" on the server. Only used if non-empty. If PHP is configured with safe mode, no files outside this directory are served. 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_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
In what directory PHP should look for dynamically loadable extensions. See also: enable_dl, and dl().
extension
string
Which dynamically loadable extensions to load when PHP starts up.
zend_extension
string
Absolute path to dynamically loadable Zend extension (for example APD) to load when PHP starts up.
zend_extension_debug
string
Variant of zend_extension for extensions compiled with debug info prior to PHP 5.3.0.
zend_extension_debug_ts
string
Variant of zend_extension for extensions compiled with debug info and thread safety prior to PHP 5.3.0.
zend_extension_ts
string
Variant of zend_extension for extensions compiled with thread safety prior to PHP 5.3.0.
cgi.check_shebang_line
boolean
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.fix_pathinfo
boolean
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
boolean
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.
Note:
Windows Users: When using IIS this option must be turned off. For OmniHTTPD or Xitami the same applies.
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.
Note:
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 0, PHP sends a 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. 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
boolean
Turns on SAPI logging when using FastCGI. Default is to enable logging.
Name | Default | Changeable | Changelog |
---|---|---|---|
file_uploads | "1" | PHP_INI_SYSTEM | PHP_INI_ALL in PHP <= 4.2.3. Available since PHP 4.0.3. |
upload_tmp_dir | NULL | PHP_INI_SYSTEM | |
max_input_nesting_level | 64 | PHP_INI_PERDIR | Available since PHP 5.3.9. |
max_input_vars | 1000 | PHP_INI_PERDIR | Available since PHP 5.3.9. |
upload_max_filesize | "2M" | PHP_INI_PERDIR | PHP_INI_ALL in PHP <= 4.2.3. |
max_file_uploads | 20 | PHP_INI_SYSTEM | Available since PHP 5.2.12. |
Here's a short explanation of the configuration directives.
file_uploads
boolean
or integer
Whether or not to allow HTTP file uploads. See also the upload_max_filesize, upload_tmp_dir, and post_max_size directives.
When an integer is used, the value is measured in bytes. Shorthand notation, as described in this FAQ, may also be used.upload_tmp_dir
string
The temporary directory used for storing files when doing file upload. Must be writable by whatever user PHP is running as. If not specified PHP will use the system's default.
If the directory specified here is not writable, PHP falls back to the system default temporary directory. If open_basedir is on, then the system default directory must be allowed for an upload to succeed.
upload_max_filesize
integer
The maximum size of an uploaded file.
When an integer is used, the value is measured in bytes. Shorthand notation, as described in this FAQ, may also be used.max_file_uploads
integer
The maximum number of files allowed to be uploaded simultaneously. Starting with PHP 5.3.4, upload fields left blank on submission do not count towards this limit.
Name | Default | Changeable | Changelog |
---|---|---|---|
sql.safe_mode | "0" | PHP_INI_SYSTEM |
Here's a short explanation of the configuration directives.
sql.safe_mode
boolean
If turned on, database connect functions that specify default values will use those values in place of supplied arguments. For default values see connect function documentation for the relevant database.
Name | Default | Changeable | Changelog |
---|---|---|---|
windows_show_crt_warning | "0" | PHP_INI_ALL | Available since PHP 5.4.0. |
Here's a short explanation of the configuration directives.
windows_show_crt_warning
boolean
This directive shows the Windows CRT warnings when enabled. These warnings were displayed by default until PHP 5.4.0.