YP/NIS
PHP Manual

Predefined Constants

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.

YPERR_ACCESS (integer)
access violation (this has only been added recently and is only available from PECL SVN for now)
YPERR_BADARGS (integer)
The function arguments are bad
YPERR_BADDB (integer)
YP database is bad
YPERR_BUSY (integer)
Database busy
YPERR_DOMAIN (integer)
cannot bind to server in this domain
YPERR_KEY (integer)
no such key in map
YPERR_MAP (integer)
no such map in server's domain
YPERR_NODOM (integer)
Local domain name not set
YPERR_NOMORE (integer)
No more records in map database
YPERR_PMAP (integer)
Can't communicate with portmapper
YPERR_RESRC (integer)
resource allocation failure
YPERR_RPC (integer)
RPC failure - domain has been unbound
YPERR_YPBIND (integer)
Can't communicate with ypbind
YPERR_YPERR (integer)
internal yp server or client error
YPERR_YPSERV (integer)
Can't communicate with ypserv
YPERR_VERS (integer)
YP version mismatch

YP/NIS
PHP Manual