下列常量由此扩展定义，且仅在此扩展编译入 PHP 或在运行时动态载入时可用。
IIS_READ
(int)
IIS_WRITE
(int)
IIS_EXECUTE
(int)
IIS_SCRIPT
(int)
IIS_ANONYMOUS
(int)
IIS_BASIC
(int)
IIS_NTLM
(int)
IIS_STARTING
(int)
IIS_STOPPED
(int)
IIS_PAUSED
(int)
IIS_RUNNING
(int)