<html lang="en">
<head>
<title>Services in the NSS configuration - 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="NSS-Configuration-File.html#NSS-Configuration-File" title="NSS Configuration File">
<link rel="prev" href="NSS-Configuration-File.html#NSS-Configuration-File" title="NSS Configuration File">
<link rel="next" href="Actions-in-the-NSS-configuration.html#Actions-in-the-NSS-configuration" title="Actions in the NSS configuration">
<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="Services-in-the-NSS-configuration"></a>
<p>
Next:&nbsp;<a rel="next" accesskey="n" href="Actions-in-the-NSS-configuration.html#Actions-in-the-NSS-configuration">Actions in the NSS configuration</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="NSS-Configuration-File.html#NSS-Configuration-File">NSS Configuration File</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="NSS-Configuration-File.html#NSS-Configuration-File">NSS Configuration File</a>
<hr>
</div>

<h4 class="subsection">28.2.1 Services in the NSS configuration File</h4>

<p>The above example file mentions four different services: <code>files</code>,
<code>db</code>, <code>nis</code>, and <code>nisplus</code>.  This does not mean these
services are available on all sites and it does also not mean these are
all the services which will ever be available.

   <p>In fact, these names are simply strings which the NSS code uses to find
the implicitly addressed functions.  The internal interface will be
described later.  Visible to the user are the modules which implement an
individual service.

   <p>Assume the service <var>name</var> shall be used for a lookup.  The code for
this service is implemented in a module called <samp><span class="file">libnss_</span><var>name</var></samp>. 
On a system supporting shared libraries this is in fact a shared library
with the name (for example) <samp><span class="file">libnss_</span><var>name</var><span class="file">.so.2</span></samp>.  The number
at the end is the currently used version of the interface which will not
change frequently.  Normally the user should not have to be cognizant of
these files since they should be placed in a directory where they are
found automatically.  Only the names of all available services are
important.

   </body></html>