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(integer)
- 
      
       The current PHP "major" version as an integer (e.g., int(5) 
       from version "5.2.7-extra"). Available since PHP 5.2.7.
      
     
- 
      PHP_MINOR_VERSION(integer)
- 
      
       The current PHP "minor" version as an integer (e.g., int(2) 
       from version "5.2.7-extra"). Available since PHP 5.2.7.
      
     
- 
      PHP_RELEASE_VERSION(integer)
- 
      
       The current PHP "release" version as an integer (e.g., int(7) 
       from version "5.2.7-extra"). Available since PHP 5.2.7.
      
     
- 
      PHP_VERSION_ID(integer)
- 
      
       The current PHP version as an integer, useful for 
       version comparisons (e.g., int(50207) from version "5.2.7-extra").
       Available since PHP 5.2.7.
      
     
- 
      
       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. Available since
       PHP 5.2.7.
      
     
- 
      PHP_ZTS(integer)
- 
      
       Available since PHP 5.2.7.
      
     
- 
      PHP_DEBUG(integer)
- 
      
       Available since PHP 5.2.7.
      
     
- 
      PHP_MAXPATHLEN(integer)
- 
      
       The maximum length of filenames (including path) supported
       by this build of PHP. Available since PHP 5.3.0.
      
     
- 
      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.
       Available since PHP 5.0.2
      
     
- 
      PHP_INT_MAX(integer)
- 
      
       The largest integer supported in this build of PHP. Usually int(2147483647)
       in 32 bit systems and int(9223372036854775807) in 64 bit systems.
       Available since PHP 5.0.5
      
     
- 
      PHP_INT_MIN(integer)
- 
      
       The smallest integer supported in this build of PHP. Usually int(-2147483648) in 32 bit systems and
       int(-9223372036854775808) in 64 bit systems. Available since PHP 7.0.0.
       Usually, PHP_INT_MIN === ~PHP_INT_MAX.
      
     
- 
      PHP_INT_SIZE(integer)
- 
      
       The size of an integer in bytes in this build of PHP. Available since PHP 5.0.5
      
     
- 
      PHP_FLOAT_DIG(integer)
- 
      
       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)
- 
      
       
      
     
- 
      PHP_PREFIX(string)
- 
      
       The value "--prefix" was set to at configure.
      
     
- 
      PHP_BINDIR(string)
- 
      
       Specifies where the binaries were installed into.
      
     
- 
      PHP_BINARY(string)
- 
      
       Specifies the PHP binary path during script execution.
       Available since PHP 5.4.
      
     
- 
      PHP_MANDIR(string)
- 
      
       Specifies where the manpages were installed into.
       Available since PHP 5.3.7.
      
     
- 
      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(string)
- 
      
       The maximum number of file descriptors for select system calls. Available
       as of PHP 7.1.0.
      
     
- 
      E_ERROR(integer)
- 
      
       Error reporting constant
      
     
- 
      E_WARNING(integer)
- 
      
       Error reporting constant
      
     
- 
      E_PARSE(integer)
- 
      
       Error reporting constant
      
     
- 
      E_NOTICE(integer)
- 
      
       Error reporting constant
      
     
- 
      E_CORE_ERROR(integer)
- 
      
       Error reporting constant
      
     
- 
      E_CORE_WARNING(integer)
- 
      
       Error reporting constant
      
     
- 
      E_COMPILE_ERROR(integer)
- 
      
       Error reporting constant
      
     
- 
      E_COMPILE_WARNING(integer)
- 
      
       Error reporting constant
      
     
- 
      E_USER_ERROR(integer)
- 
      
       Error reporting constant
      
     
- 
      E_USER_WARNING(integer)
- 
      
       Error reporting constant
      
     
- 
      E_USER_NOTICE(integer)
- 
      
       Error reporting constant
      
     
- 
      E_RECOVERABLE_ERROR(integer)
- 
      
       Error reporting constant.
       Available since PHP 5.2.0
      
     
- 
      E_DEPRECATED(integer)
- 
      
       Error reporting constant.
       Available since PHP 5.3.0
      
     
- 
      E_USER_DEPRECATED(integer)
- 
      
       Error reporting constant.
       Available since PHP 5.3.0
      
     
- 
      E_ALL(integer)
- 
      
       Error reporting constant
      
     
- 
      E_STRICT(integer)
- 
      
       Error reporting constant
      
     
- 
      __COMPILER_HALT_OFFSET__(integer)
- 
      
       Available since PHP 5.1.0
      
     
- 
      TRUE(boolean)
- 
      
       See Booleans.
      
     
- 
      FALSE(boolean)
- 
      
       See Booleans.
      
     
- 
      NULL(null)
- 
      
       See Null.
      
     
- 
      PHP_WINDOWS_EVENT_CTRL_C(integer)
- 
      
       A Windows CTRL+C event.
       Available as of PHP 7.4.0 (Windows only).
      
     
- 
      PHP_WINDOWS_EVENT_CTRL_BREAK(integer)
- 
      
       A Windows CTRL+BREAK event.
       Available as of PHP 7.4.0 (Windows only).
      
     
    See also: Magic
    constants.