Provided by: libnet-nis-perl_0.44-3_amd64 
NAME
Net::NIS - Interface to Sun's Network Information Service
SYNOPSIS
use Net::NIS;
tie %hash, 'Net::NIS', $mapname [, $domainname];
$value = $hash{$key};
or
($status, $value) = Net::NIS::yp_match
(Net::NIS::yp_get_default_domain(),
$mapname, $key);
DESCRIPTION
The Net::NIS interface comes in three parts:
1. raw
The first part is the raw implementation of the NIS API.
2. OO
The second is the object interface, described in Net::NIS::Table.
3. Tie
The third is a new 'Tied' interface, allowing simple access to NIS maps using Perl hashes.
This document describes the NIS API implementation and the 'Tied' mechanism.
Tied Implementation
NIS maps are simple key/value pairs, perfectly suited for Perl hashes. Net::NIS allows any given NIS map
to be treated as a hash (read-only). Usage is:
tie %hash, 'Net::NIS', $mapname [, $domainname];
$mapname must be specified, and be a valid map in the given domain. If the file /var/yp/nicknames
exists, it is used to obtain a list of acceptable shortcut names, such as "aliases" for "mail.aliases".
Otherwise, a hardcoded set of the "usual suspects" is consulted.
If $domainname is not given, the "yp_get_default_domain" function is used to determine the current NIS
domain. This is usually the same as will be displayed by the "domainname" command.
If Net::NIS cannot tie to a given map, it returns "undef", with an appropriate error value in the
variable $yperr. See "ERRORS".
To look up an entry in a YP map, simply use the entry name as a key in the tied hash. Net::NIS returns a
string if the key exists in the map, or "undef" if it is not found. For any errors other than YPERR_KEY,
Net::NIS raises a fatal exception through "croak".
Example
tie %alias, 'Net::NIS', 'mail.aliases'
or die "Cannot tie to mail.aliases YP map: $yperr\n";
print "postmaster is ", $alias{postmaster} || "<unknown>", "\n";
As a special case, the magic map __YPMASTER can be used as an equivalent to 'ypwhich -m':
tie %ypmaster, 'Net::NIS', '__YPMASTER' or die ...;
printf "ypmaster(passwd) = %s\n", $ypmaster{'passwd.byname'};
print $_, "\n" for sort keys %ypmaster; # Only works on Linux!
Note that keys() only works on Linux, because Linux includes a helpful yp_maplist() function. On Linux,
you can get a list of existing YP maps. On other OSes, you can't -- but given the name of an existing
map, $ypmaster{$map} will work as expected.
NIS API Implementation
The NIS package implements all functions described in the ypclnt(3N) manual page.
The following commands have been implemented:
yp_bind($domain)
Bind the process to a NIS server for the domain $domain. This function is rarely needed. See
yp_bind(3N).
yp_unbind($domain)
Unbind the process from the specified $domain. This function is also rarely required. See
yp_unbind(3N).
$domain = yp_get_default_domain()
Return the host's local domain. (The same as the domainname program). See
yp_get_default_domain(3N).
($status, $value) = yp_match($domain, $map, $key)
Return the $value for the given $key in the $map for the domain $domain. The $key must be an exact
match for an item in the map (i.e. yp_match does no partial matching. The $value is only valid if
$status is equal to YPERR_SUCCESS.
If called in scalar context, yp_match returns only $value, and it is up to the user to check $yperr.
($status, $key, $value) = yp_first($domain, $map)
Return the first key-value pair from $map in $domain. As the NIS maps are stored in a DBM table,
the order of the returned values is not obvious.
($status, $key, $value) = yp_next($domain, $map, $key)
Return the next key-value pair from $map in $domain. The $key must be provided from the previous
yp_first or yp_next. The yp_first/yp_next method is not recommended, as under some circumstances,
entries can be skipped or returned twice. yp_all is a better interface to use.
($status, \%values) = yp_all($domain, $map)
The yp_all call returns an entire map in the %values associative array.
($status, $order) = yp_order($domain, $map)
This function returns the order number for $domain. Whatever that is. It mustn't be very
important, since it's not implemented on NIS+ servers running in "YP-compatibility mode". I put it
in for completeness.
($status, $name) = yp_master($domain, $map)
Returns the machine name of the master server for a map.
$error = yperr_string($status) [DEPRECATED, use $yperr]
Returns a string representation of the error code passed in $status.
$status = ypprot_err($code) [DEPRECATED]
Translates a NIS name service protocol error code to a ypclnt layer error code. Only used for the C
version of yp_all, and it is only implemented here for completeness.
EXPORT
The magic variable $yperr is exported by default (see "ERRORS").
Exportable constants
The following error status constants can be imported individually, or by using the ':all' symbol:
YPERR_SUCCESS There is no error
YPERR_BADARGS Args to function are bad
YPERR_RPC RPC failure
YPERR_DOMAIN Can't bind to a server with this domain
YPERR_MAP No such map in server's domain
YPERR_KEY No such key in map
YPERR_YPERR Internal yp server or client error
YPERR_RESRC Local resource allocation failure
YPERR_NOMORE No more records in map database
YPERR_PMAP Can't communicate with portmapper
YPERR_YPBIND Can't communicate with ypbind
YPERR_YPSERV Can't communicate with ypserv
YPERR_NODOM Local domain name not set
YPERR_BADDB yp data base is bad
YPERR_VERS YP version mismatch
YPERR_ACCESS Access violation
YPERR_BUSY Database is busy
ERRORS
Instead of having 'tie' succeed and the first access fail, TIEHASH() (the function executed when
performing a tie) performs some sanity checks: it ensures the validity of the domain and map names. On
failure, 'tie' returns "undef", with an appropriate error value in $yperr :
tie %myhash, 'Net::NIS', 'foo-bar'
or die "Unable to access foo-bar map: $yperr\n"
Note that the $yperr variable is magic, like Perl's $!. If accessed in a string context, it returns a
human-friendly string obtained from the "yperr_string" library function. In a numeric context, $yperr
returns the numeric status code returned from the last YP function. This can be compared against the
error constants above, if you so desire.
Other Errors
Your vendor has not defined Net::NIS macro YPERR_xxxx
This indicates that one of the standard YPERR_xxx constants is not defined in your host's
<rpcsct/ypclnt.h> file. You might see this during make test on an old system, perhaps.
Unable to find 'KEY' in 'MAP'. Reason: ...
If an attempt to access a tied variable fails for any reason other than 'no such key in map', FETCH()
raises this fatal exception. It probably indicates that YP has gone down, or there is some other fatal
error. This can be caught with eval{}, but I'm not sure what you can do about it...
AUTHOR
Copyright (c) 1995, 2002 Rik Harris (rik.harris@fulcrum.com.au), 2002-2014 Ed Santiago. All rights
reserved. This program is free software; you can redistribute it and/or modify it under the same terms
as Perl itself.
Net::NIS is currently maintained by Ed Santiago <esm@cpan.org>.
The Network Information Service (NIS) was formerly known as Sun Yellow Pages (YP). The functionality of
the two remains the same; only the name has changed. The name Yellow Pages is a registered trademark in
the United Kingdom of British Telecommunications plc, and may not be used without permission.
perl v5.38.2 2024-03-11 NIS(3pm)