<html lang="en">
<head>
<title>Netgroup Data - The GNU C Library</title>
<meta http-equiv="Content-Type" content="text/html">
<meta name="description" content="The GNU C Library">
<meta name="generator" content="makeinfo 4.13">
<link title="Top" rel="start" href="index.html#Top">
<link rel="up" href="Netgroup-Database.html#Netgroup-Database" title="Netgroup Database">
<link rel="next" href="Lookup-Netgroup.html#Lookup-Netgroup" title="Lookup Netgroup">
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
<!--
This file documents the GNU C library.

This is Edition 0.12, last updated 2007-10-27,
of `The GNU C Library Reference Manual', for version
2.8 (Sourcery G++ Lite 2011.03-41).

Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2001, 2002,
2003, 2007, 2008, 2010 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with the
Invariant Sections being ``Free Software Needs Free Documentation''
and ``GNU Lesser General Public License'', the Front-Cover texts being
``A GNU Manual'', and with the Back-Cover Texts as in (a) below.  A
copy of the license is included in the section entitled "GNU Free
Documentation License".

(a) The FSF's Back-Cover Text is: ``You have the freedom to
copy and modify this GNU manual.  Buying copies from the FSF
supports it in developing GNU and promoting software freedom.''-->
<meta http-equiv="Content-Style-Type" content="text/css">
<style type="text/css"><!--
  pre.display { font-family:inherit }
  pre.format  { font-family:inherit }
  pre.smalldisplay { font-family:inherit; font-size:smaller }
  pre.smallformat  { font-family:inherit; font-size:smaller }
  pre.smallexample { font-size:smaller }
  pre.smalllisp    { font-size:smaller }
  span.sc    { font-variant:small-caps }
  span.roman { font-family:serif; font-weight:normal; } 
  span.sansserif { font-family:sans-serif; font-weight:normal; } 
--></style>
<link rel="stylesheet" type="text/css" href="../cs.css">
</head>
<body>
<div class="node">
<a name="Netgroup-Data"></a>
<p>
Next:&nbsp;<a rel="next" accesskey="n" href="Lookup-Netgroup.html#Lookup-Netgroup">Lookup Netgroup</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="Netgroup-Database.html#Netgroup-Database">Netgroup Database</a>
<hr>
</div>

<h4 class="subsection">29.16.1 Netgroup Data</h4>

<p><a name="index-Netgroup-3424"></a>Sometimes it is useful to group users according to other criteria
(see <a href="Group-Database.html#Group-Database">Group Database</a>).  E.g., it is useful to associate a certain
group of users with a certain machine.  On the other hand grouping of
host names is not supported so far.

   <p>In Sun Microsystems SunOS appeared a new kind of database, the netgroup
database.  It allows grouping hosts, users, and domains freely, giving
them individual names.  To be more concrete, a netgroup is a list of triples
consisting of a host name, a user name, and a domain name where any of
the entries can be a wildcard entry matching all inputs.  A last
possibility is that names of other netgroups can also be given in the
list specifying a netgroup.  So one can construct arbitrary hierarchies
without loops.

   <p>Sun's implementation allows netgroups only for the <code>nis</code> or
<code>nisplus</code> service, see <a href="Services-in-the-NSS-configuration.html#Services-in-the-NSS-configuration">Services in the NSS configuration</a>.  The
implementation in the GNU C library has no such restriction.  An entry
in either of the input services must have the following form:

<pre class="smallexample">     <var>groupname</var> ( <var>groupname</var> | <code>(</code><var>hostname</var><code>,</code><var>username</var><code>,</code><code>domainname</code><code>)</code> )+
</pre>
   <p>Any of the fields in the triple can be empty which means anything
matches.  While describing the functions we will see that the opposite
case is useful as well.  I.e., there may be entries which will not
match any input.  For entries like this, a name consisting of the single
character <code>-</code> shall be used.

   </body></html>