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.
Note: This extension is not available on Windows platforms.
None besides functions from standard Unix libraries which are always available (either libc or libnsl, configure will detect which one to use).
To get these functions to work, you have to configure PHP with --enable-yp.
This extension has no configuration directives defined in php.ini.
The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.