NIS (formerly called Yellow Pages) allows network management of important administrative files (e.g. the password file). For more information refer to the NIS manpage and The Linux NIS(YP)/NYS/NIS+ HOWTO. There is also a book called Managing NFS and NIS by Hal Stern.
注: 该扩展模块不适用于 Windows 平台!
None besides functions from standard Unix libraries which are always available (either libc or libnsl, configure will detect which one to use).
由于这些常量是由该扩展模块定义的,因此只有在该扩展模块被编译到 PHP 中,或者在运行时被动态加载后,这些常量才有效。