Predefined Constants

The constants below are always available as part of the PHP core.

**Pre-defined phpcredits constants**
Constant	Value	Description
`CREDITS_GROUP`	1	A list of the core developers
`CREDITS_GENERAL`	2	General credits: Language design and concept, PHP authors and SAPI module.
`CREDITS_SAPI`	4	A list of the server API modules for PHP, and their authors.
`CREDITS_MODULES`	8	A list of the extension modules for PHP, and their authors.
`CREDITS_DOCS`	16	The credits for the documentation team.
`CREDITS_FULLPAGE`	32	Usually used in combination with the other flags. Indicates that a complete stand-alone HTML page needs to be printed including the information indicated by the other flags.
`CREDITS_QA`	64	The credits for the quality assurance team.
`CREDITS_ALL`	-1	All the credits, equivalent to using: CREDITS_DOCS + CREDITS_GENERAL + CREDITS_GROUP + CREDITS_MODULES + CREDITS_QA CREDITS_FULLPAGE. It generates a complete stand-alone HTML page with the appropriate tags. This is the default value.

**phpinfo constants**
Constant	Value	Description
`INFO_GENERAL`	1	The configuration line, `php.ini` location, build date, Web Server, System and more.
`INFO_CREDITS`	2	PHP Credits. See also phpcredits.
`INFO_CONFIGURATION`	4	Current Local and Master values for PHP directives. See also ini_get.
`INFO_MODULES`	8	Loaded modules and their respective settings.
`INFO_ENVIRONMENT`	16	Environment Variable information that's also available in `$_ENV`.
`INFO_VARIABLES`	32	Shows all predefined variables from EGPCS (Environment, GET, POST, Cookie, Server).
`INFO_LICENSE`	64	PHP License information. See also the » license faq.
`INFO_ALL`	-1	Shows all of the above. This is the default value.

**INI constants**
Constant	Value	Description
INI_USER	1	Unused
INI_PERDIR	2	Unused
INI_SYSTEM	4	Unused
INI_ALL	7	Unused

Assert constants, these values are used to set the assertion options in assert_options.

**assert constants**
Constant	INI Setting	Description
`ASSERT_ACTIVE`	assert.active	Enable assert evaluation.
`ASSERT_CALLBACK`	assert.callback	Callback to call on failed assertions.
`ASSERT_BAIL`	assert.bail	Terminate execution on failed assertions.
`ASSERT_WARNING`	assert.warning	Issues a PHP warning for each failed assertion
`ASSERT_QUIET_EVAL`	assert.quiet_eval	Disable error_reporting during assertion expression evaluation.

The following constants are only available if the host operating system is Windows, and can tell different versioning information so its possible to detect various features and make use of them. They are all available as of PHP 5.3.0.

**Windows specific constants**
Constant	Description
`PHP_WINDOWS_VERSION_MAJOR`	The major version of Windows, this can be either 4 (NT4/Me/98/95), 5 (XP/2003 R2/2003/2000) or 6 (Vista/2008/7/8/8.1).
`PHP_WINDOWS_VERSION_MINOR`	The minor version of Windows, this can be either 0 (Vista/2008/2000/NT4/95), 1 (XP), 2 (2003 R2/2003/XP x64), 10 (98) or 90 (ME).
`PHP_WINDOWS_VERSION_BUILD`	The Windows build number (for example, Windows Vista with SP1 applied is build 6001)
`PHP_WINDOWS_VERSION_PLATFORM`	The platform that PHP currently is running on, this value is 2 on Windows Vista/XP/2000/NT4, Server 2008/2003 and on Windows ME/98/95 this value is 1.
`PHP_WINDOWS_VERSION_SP_MAJOR`	The major version of the service pack installed, this value is 0 if no service pack is installed. For example, Windows XP with service pack 3 installed will make this value 3.
`PHP_WINDOWS_VERSION_SP_MINOR`	The minor version of the service pack installed, this value is 0 if no service pack is installed.
`PHP_WINDOWS_VERSION_SUITEMASK`	The suitemask is a bitmask that can tell if various features of Windows is installed, see the table below for possible bitfield values.
`PHP_WINDOWS_VERSION_PRODUCTTYPE`	This contains the value used to determine the PHP_WINDOWS_NT_* constants. This value may be one of the PHP_WINDOWS_NT_* constants indicating the platform type.
`PHP_WINDOWS_NT_DOMAIN_CONTROLLER`	This is a domain controller
`PHP_WINDOWS_NT_SERVER`	This is a server system (eg. Server 2008/2003/2000), note that if this is a domain controller its reported as `PHP_WINDOWS_NT_DOMAIN_CONTROLLER`.
`PHP_WINDOWS_NT_WORKSTATION`	This is a workstation system (eg. Vista/XP/2000/NT4)

This table shows a list of features that can be checked for using the PHP_WINDOWS_VERSION_SUITEMASK bitmask.

**Windows suitemask bitfields**
Bits	Description
0x00000004	Microsoft BackOffice components are installed.
0x00000400	Windows Server 2003, Web Edition is installed.
0x00004000	Windows Server 2003, Compute Cluster Edition is installed.
0x00000080	Windows Server 2008 Datacenter, Windows Server 2003, Datacenter Edition or Windows 2000 Datacenter Server is installed.
0x00000002	Windows Server 2008 Enterprise, Windows Server 2003, Enterprise Edition, Windows 2000 Advanced Server, or Windows NT Server 4.0 Enterprise Edition is installed.
0x00000040	Windows XP Embedded is installed.
0x00000200	Windows Vista Home Premium, Windows Vista Home Basic, or Windows XP Home Edition is installed.
0x00000100	Remote Desktop is supported, but only one interactive session is supported. This value is set unless the system is running in application server mode.
0x00000001	Microsoft Small Business Server was once installed on the system, but may have been upgraded to another version of Windows.
0x00000020	Microsoft Small Business Server is installed with the restrictive client license in force.
0x00002000	Windows Storage Server 2003 R2 or Windows Storage Server 2003 is installed.
0x00000010	Terminal Services is installed. This value is always set. If this value is set but 0x00000100 is not set, then the system is running in application server mode.
0x00008000	Windows Home Server is installed.