预定义常量

内核预定义常量

这些常量在 PHP 的内核中定义。它包含 PHP、Zend 引擎和 SAPI 模块。

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.
PHP_EXTRA_VERSION (string)
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. Either 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.参见 php_sapi_name()
PHP_EOL (string)
The correct 'End Of Line' symbol for this platform.自 PHP 5.0.2 起可用
PHP_INT_MAX (integer)
The largest integer supported in this build of PHP. Usually int(2147483647).自 PHP 5.0.5 起可用
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. 自 PHP 5.0.5 起可用
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 floating point number. 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)
自 PHP 5.1.0 起有效
TRUE (boolean)
See Booleans.
FALSE (boolean)
See Booleans.
NULL (null)
See Null.

参见魔术常量

标准预定义常量

所有在核心扩展 的常量是 PHP 默认定义的。

User Contributed Notes

nabikaz at gmail dot com 10-Nov-2016 10:18
Don't use `PHP_EOL` for textarea of form to array, use it:

array_values(array_filter(explode("\n", str_replace("\r", '', $_POST['data']))))
Anonymous 27-Jan-2015 03:25
PHP_EOL can be used like that:

<?php

$data
= 'some data'.PHP_EOL;
$fp = fopen('somefile', 'a');
fwrite($fp, $data);

?>

Which is the same of \r\n or \n depending on the OS.
You can put those lines in a while for example, and create a log file.
rdcapasso 08-Sep-2013 09:16
Volker's getOS() function needs to have the order of cases changed in the switch statement since "darwin" contains "win", which means that both "windows" and "darwin" will return self::OS_WIN. I've moved the 'dar' case above the 'win' case:

<?php
class System {

    const
OS_UNKNOWN = 1;
    const
OS_WIN = 2;
    const
OS_LINUX = 3;
    const
OS_OSX = 4;

   
/**
     * @return int
     */
   
static public function getOS() {
        switch (
true) {
            case
stristr(PHP_OS, 'DAR'): return self::OS_OSX;
            case
stristr(PHP_OS, 'WIN'): return self::OS_WIN;
            case
stristr(PHP_OS, 'LINUX'): return self::OS_LINUX;
            default : return
self::OS_UNKNOWN;
        }
    }

}
?>