Core Predefined Constants
These constants are defined by the PHP core. This includes PHP, the Zend engine, and SAPI modules.
PHP_VERSION
(string) - The current PHP version as a string in "major.minor.release[extra]" notation.
PHP_MAJOR_VERSION
(int) - The current PHP "major" version as an integer (e.g., int(5) from version "5.2.7-extra").
PHP_MINOR_VERSION
(int) - The current PHP "minor" version as an integer (e.g., int(2) from version "5.2.7-extra").
PHP_RELEASE_VERSION
(int) - The current PHP "release" version as an integer (e.g., int(7) from version "5.2.7-extra").
PHP_VERSION_ID
(int) - The current PHP version as an integer, useful for version comparisons (e.g., int(50207) from version "5.2.7-extra").
- The current PHP "extra" version as a string (e.g., '-extra' from version "5.2.7-extra"). Often used by distribution vendors to indicate a package version.
ZEND_THREAD_SAFE
(bool) - Indicates whether the current build of PHP is thread safe.
ZEND_DEBUG_BUILD
(bool) - Indicates whether the current build of PHP is a debug build.
PHP_ZTS
(int) - Indicates whether the current build of PHP is thread safe.
PHP_DEBUG
(int) - Indicates whether the current build of PHP is a debug build.
PHP_MAXPATHLEN
(int) - The maximum length of filenames (including path) supported by this build of PHP.
PHP_OS
(string) - The operating system PHP was built for.
PHP_OS_FAMILY
(string) - The operating system family PHP was built for. One of
'Windows'
, 'BSD'
, 'Darwin'
, 'Solaris'
, 'Linux'
or 'Unknown'
. Available as of PHP 7.2.0. PHP_SAPI
(string) - The Server API for this build of PHP. See also php_sapi_name().
PHP_EOL
(string) - The correct 'End Of Line' symbol for this platform.
PHP_INT_MAX
(int) - The largest integer supported in this build of PHP. Usually int(2147483647) in 32 bit systems and int(9223372036854775807) in 64 bit systems.
PHP_INT_MIN
(int) - The smallest integer supported in this build of PHP. Usually int(-2147483648) in 32 bit systems and int(-9223372036854775808) in 64 bit systems. Usually, PHP_INT_MIN === ~PHP_INT_MAX.
PHP_INT_SIZE
(int) - The size of an integer in bytes in this build of PHP.
PHP_FLOAT_DIG
(int) - Number of decimal digits that can be rounded into a float and back without precision loss. Available as of PHP 7.2.0.
PHP_FLOAT_EPSILON
(float) - Smallest representable positive number x, so that
x + 1.0 != 1.0
. Available as of PHP 7.2.0. PHP_FLOAT_MIN
(float) - Smallest representable positive floating point number. If you need the smallest representable negative floating point number, use
- PHP_FLOAT_MAX
. Available as of PHP 7.2.0. PHP_FLOAT_MAX
(float) - Largest representable floating point number. Available as of PHP 7.2.0.
DEFAULT_INCLUDE_PATH
(string) PEAR_INSTALL_DIR
(string) PEAR_EXTENSION_DIR
(string) PHP_EXTENSION_DIR
(string) - The default directory where to look for dynamically loadable extensions (unless overridden by extension_dir). Defaults to
PHP_PREFIX
(or PHP_PREFIX . "\\ext"
on Windows). PHP_PREFIX
(string) - The value --prefix was set to at configure. On Windows, it is the value --with-prefix was set to at configure.
PHP_BINDIR
(string) - The value --bindir was set to at configure. On Windows, it is the value --with-prefix was set to at configure.
PHP_BINARY
(string) - Specifies the PHP binary path during script execution.
PHP_MANDIR
(string) - Specifies where the manpages were installed into.
PHP_LIBDIR
(string) PHP_DATADIR
(string) PHP_SYSCONFDIR
(string) PHP_LOCALSTATEDIR
(string) PHP_CONFIG_FILE_PATH
(string) PHP_CONFIG_FILE_SCAN_DIR
(string) PHP_SHLIB_SUFFIX
(string) - The build-platform's shared library suffix, such as "so" (most Unixes) or "dll" (Windows).
PHP_FD_SETSIZE
(int) - The maximum number of file descriptors for select system calls. Available as of PHP 7.1.0.
E_ERROR
(int) - Error reporting constant
E_WARNING
(int) - Error reporting constant
E_PARSE
(int) - Error reporting constant
E_NOTICE
(int) - Error reporting constant
E_CORE_ERROR
(int) - Error reporting constant
E_CORE_WARNING
(int) - Error reporting constant
E_COMPILE_ERROR
(int) - Error reporting constant
E_COMPILE_WARNING
(int) - Error reporting constant
E_USER_ERROR
(int) - Error reporting constant
E_USER_WARNING
(int) - Error reporting constant
E_USER_NOTICE
(int) - Error reporting constant
E_RECOVERABLE_ERROR
(int) - Error reporting constant.
E_DEPRECATED
(int) - Error reporting constant.
E_USER_DEPRECATED
(int) - Error reporting constant.
E_ALL
(int) - Error reporting constant
E_STRICT
(int) - Error reporting constant
__COMPILER_HALT_OFFSET__
(int) true
(bool) - See Booleans.
false
(bool) - See Booleans.
null
(null) - See Null.
PHP_WINDOWS_EVENT_CTRL_C
(int) - A Windows
CTRL+C
event. Available as of PHP 7.4.0 (Windows only). PHP_WINDOWS_EVENT_CTRL_BREAK
(int) - A Windows
CTRL+BREAK
event. Available as of PHP 7.4.0 (Windows only). PHP_CLI_PROCESS_TITLE
(bool) - Indicates whether the setting and getting of the process title is available. Available only under the CLI SAPI.
STDERR
(resource) - An already opened stream to
stderr
. Available only under the CLI SAPI. STDIN
(resource) - An already opened stream to
stdin
. Available only under the CLI SAPI. STDOUT
(resource) - An already opened stream to
stdout
. Available only under the CLI SAPI.
See also: Magic constants.