PHP: Predefined Constants - Manual (original) (raw)
Core Predefined Constants
These constants are defined by the PHP core. This includes PHP, the Zend engine, and SAPI modules.
[PHP_VERSION](reserved.constants.php#constant.php-version) (string)
The current PHP version as a string in "major.minor.release[extra]" notation.
[PHP_MAJOR_VERSION](reserved.constants.php#constant.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](reserved.constants.php#constant.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](reserved.constants.php#constant.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](reserved.constants.php#constant.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](reserved.constants.php#constant.zend-thread-safe) (bool)
Indicates whether the current build of PHP is thread safe.
[ZEND_DEBUG_BUILD](reserved.constants.php#constant.zend-debug-build) (bool)
Indicates whether the current build of PHP is a debug build.
[PHP_ZTS](reserved.constants.php#constant.php-zts) (bool) Alias of [ZEND_THREAD_SAFE](reserved.constants.php#constant.zend-thread-safe)
Indicates whether the current build of PHP is thread safe.
[PHP_DEBUG](reserved.constants.php#constant.php-debug) (bool) Alias of [ZEND_DEBUG_BUILD](reserved.constants.php#constant.zend-debug-build)
Indicates whether the current build of PHP is a debug build.
[DEBUG_BACKTRACE_PROVIDE_OBJECT](reserved.constants.php#constant.debug-backtrace-provide-object) (int)
Populate the "object" index.
[DEBUG_BACKTRACE_IGNORE_ARGS](reserved.constants.php#constant.debug-backtrace-ignore-args) (int)
Don't include the argument information for functions in the stack trace.
[PHP_MAXPATHLEN](reserved.constants.php#constant.php-maxpathlen) (int)
The maximum length of filenames (including path) supported by this build of PHP.
[PHP_OS](reserved.constants.php#constant.php-os) (string)
The operating system PHP was built for.
[PHP_OS_FAMILY](reserved.constants.php#constant.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](reserved.constants.php#constant.php-sapi) (string)
The Server API for this build of PHP. See also php_sapi_name().
[PHP_EOL](reserved.constants.php#constant.php-eol) (string)
The correct 'End Of Line' symbol for this platform.
[PHP_INT_MAX](reserved.constants.php#constant.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](reserved.constants.php#constant.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](reserved.constants.php#constant.php-int-size) (int)
The size of an integer in bytes in this build of PHP.
[PHP_FLOAT_DIG](reserved.constants.php#constant.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](reserved.constants.php#constant.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](reserved.constants.php#constant.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](reserved.constants.php#constant.php-float-max) (float)
Largest representable floating point number. Available as of PHP 7.2.0.
[DEFAULT_INCLUDE_PATH](reserved.constants.php#constant.default-include-path) (string)
[PEAR_INSTALL_DIR](reserved.constants.php#constant.pear-install-dir) (string)
[PEAR_EXTENSION_DIR](reserved.constants.php#constant.pear-extension-dir) (string)
[PHP_EXTENSION_DIR](reserved.constants.php#constant.php-extension-dir) (string)
The default directory where to look for dynamically loadable extensions (unless overridden by extension_dir). Defaults to [PHP_PREFIX](reserved.constants.php#constant.php-prefix) (or PHP_PREFIX . "\\ext" on Windows).
[PHP_PREFIX](reserved.constants.php#constant.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](reserved.constants.php#constant.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_SBINDIR](reserved.constants.php#constant.php-sbindir) (string)
The value --sbindir was set to at configure. On Windows, it is the value --with-prefix was set to at configure. Available as of PHP 8.4.0.
[PHP_BINARY](reserved.constants.php#constant.php-binary) (string)
Specifies the PHP binary path during script execution.
[PHP_MANDIR](reserved.constants.php#constant.php-mandir) (string)
Specifies where the manpages were installed into.
[PHP_LIBDIR](reserved.constants.php#constant.php-libdir) (string)
[PHP_DATADIR](reserved.constants.php#constant.php-datadir) (string)
[PHP_SYSCONFDIR](reserved.constants.php#constant.php-sysconfdir) (string)
[PHP_LOCALSTATEDIR](reserved.constants.php#constant.php-localstatedir) (string)
[PHP_CONFIG_FILE_PATH](reserved.constants.php#constant.php-config-file-path) (string)
[PHP_CONFIG_FILE_SCAN_DIR](reserved.constants.php#constant.php-config-file-scan-dir) (string)
[PHP_SHLIB_SUFFIX](reserved.constants.php#constant.php-shlib-suffix) (string)
The build-platform's shared library suffix, such as "so" (most Unixes) or "dll" (Windows).
[PHP_FD_SETSIZE](reserved.constants.php#constant.php-fd-setsize) (int)
The maximum number of file descriptors for select system calls. Available as of PHP 7.1.0.
[E_ERROR](errorfunc.constants.php#constant.e-error) (int)
[E_WARNING](errorfunc.constants.php#constant.e-warning) (int)
[E_PARSE](errorfunc.constants.php#constant.e-parse) (int)
[E_NOTICE](errorfunc.constants.php#constant.e-notice) (int)
[E_CORE_ERROR](errorfunc.constants.php#constant.e-core-error) (int)
[E_CORE_WARNING](errorfunc.constants.php#constant.e-core-warning) (int)
[E_COMPILE_ERROR](errorfunc.constants.php#constant.e-compile-error) (int)
[E_COMPILE_WARNING](errorfunc.constants.php#constant.e-compile-warning) (int)
[E_USER_ERROR](errorfunc.constants.php#constant.e-user-error) (int)
[E_USER_WARNING](errorfunc.constants.php#constant.e-user-warning) (int)
[E_USER_NOTICE](errorfunc.constants.php#constant.e-user-notice) (int)
[E_RECOVERABLE_ERROR](errorfunc.constants.php#constant.e-recoverable-error) (int)
[E_DEPRECATED](errorfunc.constants.php#constant.e-deprecated) (int)
[E_USER_DEPRECATED](errorfunc.constants.php#constant.e-user-deprecated) (int)
[E_ALL](errorfunc.constants.php#constant.e-all) (int)
[E_STRICT](errorfunc.constants.php#constant.e-strict) (int)
[__COMPILER_HALT_OFFSET__](misc.constants.php#constant.compiler-halt-offset) (int)
[true](reserved.constants.php#constant.true) (bool)
See Booleans.
[false](reserved.constants.php#constant.false) (bool)
See Booleans.
[null](reserved.constants.php#constant.null) (null)
See Null.
[PHP_WINDOWS_EVENT_CTRL_C](reserved.constants.php#constant.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](reserved.constants.php#constant.php-windows-event-ctrl-break) (int)
A Windows CTRL +BREAK event. Available as of PHP 7.4.0 (Windows only).
[PHP_CLI_PROCESS_TITLE](reserved.constants.php#constant.php-cli-process-title) (bool)
Indicates whether the setting and getting of the process title is available. Available only under the CLI SAPI.
[STDERR](reserved.constants.php#constant.stderr) (resource)
An already opened stream to stderr. Available only under the CLI SAPI.
[STDIN](reserved.constants.php#constant.stdin) (resource)
An already opened stream to stdin. Available only under the CLI SAPI.
[STDOUT](reserved.constants.php#constant.stdout) (resource)
An already opened stream to stdout. Available only under the CLI SAPI.
See also: Magic constants.
Standard Predefined Constants
All constants from core extensions are defined in PHP by default.
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