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)
   PHP_OS
    (string)
   PHP_SAPI
     (string)
   PHP_EOL
    (string)
   PHP_INT_MAX
    (integer)
   PHP_INT_SIZE
    (integer)
   DEFAULT_INCLUDE_PATH
    (string)
   PEAR_INSTALL_DIR
    (string)
   PEAR_EXTENSION_DIR
    (string)
   PHP_EXTENSION_DIR
    (string)
   PHP_PREFIX
    (string)
   PHP_BINDIR
    (string)
   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)
   PHP_OUTPUT_HANDLER_START
    (integer)
   PHP_OUTPUT_HANDLER_CONT
    (integer)
   PHP_OUTPUT_HANDLER_END
    (integer)
   E_ERROR
    (integer)
   E_WARNING
    (integer)
   E_PARSE
    (integer)
   E_NOTICE
    (integer)
   E_CORE_ERROR
    (integer)
   E_CORE_WARNING
    (integer)
   E_COMPILE_ERROR
    (integer)
   E_COMPILE_WARNING
    (integer)
   E_USER_ERROR
    (integer)
   E_USER_WARNING
    (integer)
   E_USER_NOTICE
    (integer)
   E_ALL
    (integer)
   E_STRICT
    (integer)
   __COMPILER_HALT_OFFSET__
    (integer)
   参见魔术常量。
这些常量是 PHP 默认定义的。
EXTR_OVERWRITE
      (integer)
     EXTR_SKIP
      (integer)
     EXTR_PREFIX_SAME
      (integer)
     EXTR_PREFIX_ALL
      (integer)
     EXTR_PREFIX_INVALID
      (integer)
     EXTR_PREFIX_IF_EXISTS
      (integer)
     EXTR_IF_EXISTS
      (integer)
     SORT_ASC
      (integer)
     SORT_DESC
      (integer)
     SORT_REGULAR
      (integer)
     SORT_NUMERIC
      (integer)
     SORT_STRING
      (integer)
     CASE_LOWER
      (integer)
     CASE_UPPER
      (integer)
     COUNT_NORMAL
      (integer)
     COUNT_RECURSIVE
      (integer)
     ASSERT_ACTIVE
      (integer)
     ASSERT_CALLBACK
      (integer)
     ASSERT_BAIL
      (integer)
     ASSERT_WARNING
      (integer)
     ASSERT_QUIET_EVAL
      (integer)
     CONNECTION_ABORTED
      (integer)
     CONNECTION_NORMAL
      (integer)
     CONNECTION_TIMEOUT
      (integer)
     INI_USER
      (integer)
     INI_PERDIR
      (integer)
     INI_SYSTEM
      (integer)
     INI_ALL
      (integer)
     M_E
      (float)
     M_LOG2E
      (float)
     M_LOG10E
      (float)
     M_LN2
      (float)
     M_LN10
      (float)
     M_PI
      (float)
     M_PI_2
      (float)
     M_PI_4
      (float)
     M_1_PI
      (float)
     M_2_PI
      (float)
     M_2_SQRTPI
      (float)
     M_SQRT2
      (float)
     M_SQRT1_2
      (float)
     CRYPT_SALT_LENGTH
      (integer)
     CRYPT_STD_DES
      (integer)
     CRYPT_EXT_DES
      (integer)
     CRYPT_MD5
      (integer)
     CRYPT_BLOWFISH
      (integer)
     DIRECTORY_SEPARATOR
      (string)
     SEEK_SET
      (integer)
     SEEK_CUR
      (integer)
     SEEK_END
      (integer)
     LOCK_SH
      (integer)
     LOCK_EX
      (integer)
     LOCK_UN
      (integer)
     LOCK_NB
      (integer)
     HTML_SPECIALCHARS
      (integer)
     HTML_ENTITIES
      (integer)
     ENT_COMPAT
      (integer)
     ENT_QUOTES
      (integer)
     ENT_NOQUOTES
      (integer)
     INFO_GENERAL
      (integer)
     INFO_CREDITS
      (integer)
     INFO_CONFIGURATION
      (integer)
     INFO_MODULES
      (integer)
     INFO_ENVIRONMENT
      (integer)
     INFO_VARIABLES
      (integer)
     INFO_LICENSE
      (integer)
     INFO_ALL
      (integer)
     CREDITS_GROUP
      (integer)
     CREDITS_GENERAL
      (integer)
     CREDITS_SAPI
      (integer)
     CREDITS_MODULES
      (integer)
     CREDITS_DOCS
      (integer)
     CREDITS_FULLPAGE
      (integer)
     CREDITS_QA
      (integer)
     CREDITS_ALL
      (integer)
     STR_PAD_LEFT
      (integer)
     STR_PAD_RIGHT
      (integer)
     STR_PAD_BOTH
      (integer)
     PATHINFO_DIRNAME
      (integer)
     PATHINFO_BASENAME
      (integer)
     PATHINFO_EXTENSION
      (integer)
     PATH_SEPARATOR 
      (string)
     CHAR_MAX
      (integer)
     LC_CTYPE
      (integer)
     LC_NUMERIC
      (integer)
     LC_TIME
      (integer)
     LC_COLLATE
      (integer)
     LC_MONETARY
      (integer)
     LC_ALL
      (integer)
     LC_MESSAGES
      (integer)
     ABDAY_1
      (integer)
     ABDAY_2
      (integer)
     ABDAY_3
      (integer)
     ABDAY_4
      (integer)
     ABDAY_5
      (integer)
     ABDAY_6
      (integer)
     ABDAY_7
      (integer)
     DAY_1
      (integer)
     DAY_2
      (integer)
     DAY_3
      (integer)
     DAY_4
      (integer)
     DAY_5
      (integer)
     DAY_6
      (integer)
     DAY_7
      (integer)
     ABMON_1
      (integer)
     ABMON_2
      (integer)
     ABMON_3
      (integer)
     ABMON_4
      (integer)
     ABMON_5
      (integer)
     ABMON_6
      (integer)
     ABMON_7
      (integer)
     ABMON_8
      (integer)
     ABMON_9
      (integer)
     ABMON_10
      (integer)
     ABMON_11
      (integer)
     ABMON_12
      (integer)
     MON_1
      (integer)
     MON_2
      (integer)
     MON_3
      (integer)
     MON_4
      (integer)
     MON_5
      (integer)
     MON_6
      (integer)
     MON_7
      (integer)
     MON_8
      (integer)
     MON_9
      (integer)
     MON_10
      (integer)
     MON_11
      (integer)
     MON_12
      (integer)
     AM_STR
      (integer)
     PM_STR
      (integer)
     D_T_FMT
      (integer)
     D_FMT
      (integer)
     T_FMT
      (integer)
     T_FMT_AMPM
      (integer)
     ERA
      (integer)
     ERA_YEAR
      (integer)
     ERA_D_T_FMT
      (integer)
     ERA_D_FMT
      (integer)
     ERA_T_FMT
      (integer)
     ALT_DIGITS
      (integer)
     INT_CURR_SYMBOL
      (integer)
     CURRENCY_SYMBOL
      (integer)
     CRNCYSTR
      (integer)
     MON_DECIMAL_POINT
      (integer)
     MON_THOUSANDS_SEP
      (integer)
     MON_GROUPING
      (integer)
     POSITIVE_SIGN
      (integer)
     NEGATIVE_SIGN
      (integer)
     INT_FRAC_DIGITS
      (integer)
     FRAC_DIGITS
      (integer)
     P_CS_PRECEDES
      (integer)
     P_SEP_BY_SPACE
      (integer)
     N_CS_PRECEDES
      (integer)
     N_SEP_BY_SPACE
      (integer)
     P_SIGN_POSN
      (integer)
     N_SIGN_POSN
      (integer)
     DECIMAL_POINT
      (integer)
     RADIXCHAR
      (integer)
     THOUSANDS_SEP
      (integer)
     THOUSEP
      (integer)
     GROUPING
      (integer)
     YESEXPR
      (integer)
     NOEXPR
      (integer)
     YESSTR
      (integer)
     NOSTR
      (integer)
     CODESET
      (integer)
     LOG_EMERG
      (integer)
     LOG_ALERT
      (integer)
     LOG_CRIT
      (integer)
     LOG_ERR
      (integer)
     LOG_WARNING
      (integer)
     LOG_NOTICE
      (integer)
     LOG_INFO
      (integer)
     LOG_DEBUG
      (integer)
     LOG_KERN
      (integer)
     LOG_USER
      (integer)
     LOG_MAIL
      (integer)
     LOG_DAEMON
      (integer)
     LOG_AUTH
      (integer)
     LOG_SYSLOG
      (integer)
     LOG_LPR
      (integer)
     LOG_NEWS
      (integer)
     LOG_UUCP
      (integer)
     LOG_CRON
      (integer)
     LOG_AUTHPRIV
      (integer)
     LOG_LOCAL0
      (integer)
     LOG_LOCAL1
      (integer)
     LOG_LOCAL2
      (integer)
     LOG_LOCAL3
      (integer)
     LOG_LOCAL4
      (integer)
     LOG_LOCAL5
      (integer)
     LOG_LOCAL6
      (integer)
     LOG_LOCAL7
      (integer)
     LOG_PID
      (integer)
     LOG_CONS
      (integer)
     LOG_ODELAY
      (integer)
     LOG_NDELAY
      (integer)
     LOG_NOWAIT
      (integer)
     LOG_PERROR
      (integer)