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<?xml version="1.0" encoding="UTF-8"?>
<!--
SPDX-FileCopyrightText: 1989 - 1993, Julianne Frances Haugh
SPDX-FileCopyrightText: 2007 - 2008, Nicolas François
SPDX-License-Identifier: BSD-3-Clause
-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
<!-- SHADOW-CONFIG-HERE -->
]>
<refentry id='shadow.3'>
<!-- $Id$ -->
<refentryinfo>
<author>
<firstname>Julianne Frances</firstname>
<surname>Haugh</surname>
<contrib>Creation, 1989</contrib>
</author>
<author>
<firstname>Thomas</firstname>
<surname>Kłoczko</surname>
<email>kloczek@pld.org.pl</email>
<contrib>shadow-utils maintainer, 2000 - 2007</contrib>
</author>
<author>
<firstname>Nicolas</firstname>
<surname>François</surname>
<email>nicolas.francois@centraliens.net</email>
<contrib>shadow-utils maintainer, 2007 - now</contrib>
</author>
</refentryinfo>
<refmeta>
<refentrytitle>shadow</refentrytitle>
<manvolnum>3</manvolnum>
<refmiscinfo class="sectdesc">Library Calls</refmiscinfo>
<refmiscinfo class="source">shadow-utils</refmiscinfo>
<refmiscinfo class="version">&SHADOW_UTILS_VERSION;</refmiscinfo>
</refmeta>
<refnamediv id='name'>
<refname>shadow</refname>
<refname>getspnam</refname>
<refpurpose>encrypted password file routines</refpurpose>
</refnamediv>
<refsect1 id='syntax'>
<title>SYNTAX</title>
<para>
<emphasis>#include <shadow.h></emphasis>
</para>
<para>
<emphasis>struct spwd *getspent();</emphasis>
</para>
<para>
<emphasis>struct spwd *getspnam(char</emphasis> <emphasis
remap='I'>*name</emphasis><emphasis>);</emphasis>
</para>
<para>
<emphasis>void setspent();</emphasis>
</para>
<para>
<emphasis>void endspent();</emphasis>
</para>
<para>
<emphasis>struct spwd *fgetspent(FILE</emphasis> <emphasis
remap='I'>*fp</emphasis><emphasis>);</emphasis>
</para>
<para>
<emphasis>struct spwd *sgetspent(char</emphasis> <emphasis
remap='I'>*cp</emphasis><emphasis>);</emphasis>
</para>
<para>
<emphasis>int putspent(struct spwd</emphasis> <emphasis
remap='I'>*p,</emphasis> <emphasis>FILE</emphasis> <emphasis
remap='I'>*fp</emphasis><emphasis>);</emphasis>
</para>
<para>
<emphasis>int lckpwdf();</emphasis>
</para>
<para>
<emphasis>int ulckpwdf();</emphasis>
</para>
</refsect1>
<refsect1 id='description'>
<title>DESCRIPTION</title>
<para>
<emphasis remap='I'>shadow</emphasis> manipulates the contents of the
shadow password file, <filename>/etc/shadow</filename>. The structure
in the <emphasis remap='I'>#include</emphasis> file is:
</para>
<programlisting>struct spwd {
char *sp_namp; /* user login name */
char *sp_pwdp; /* encrypted password */
long int sp_lstchg; /* last password change */
long int sp_min; /* days until change allowed. */
long int sp_max; /* days before change required */
long int sp_warn; /* days warning for expiration */
long int sp_inact; /* days before account inactive */
long int sp_expire; /* date when account expires */
unsigned long int sp_flag; /* reserved for future use */
}
</programlisting>
<para>The meanings of each field are:</para>
<itemizedlist mark='bullet'>
<listitem>
<para>sp_namp - pointer to null-terminated user name</para>
</listitem>
<listitem>
<para>sp_pwdp - pointer to null-terminated password</para>
</listitem>
<listitem>
<para>sp_lstchg - days since Jan 1, 1970 password was last changed</para>
</listitem>
<listitem>
<para>sp_min - days before which password may not be changed</para>
</listitem>
<listitem>
<para>sp_max - days after which password must be changed</para>
</listitem>
<listitem>
<para>sp_warn - days before password is to expire that user is warned of
pending password expiration
</para>
</listitem>
<listitem>
<para>sp_inact - days after password expires that account is considered
inactive and disabled
</para>
</listitem>
<listitem>
<para>sp_expire - days since Jan 1, 1970 when account will be disabled</para>
</listitem>
<listitem>
<para>sp_flag - reserved for future use</para>
</listitem>
</itemizedlist>
</refsect1>
<refsect1 id='description2'>
<title>DESCRIPTION</title>
<para>
<emphasis>getspent</emphasis>, <emphasis>getspname</emphasis>,
<emphasis>fgetspent</emphasis>, and <emphasis>sgetspent</emphasis>
each return a pointer to a <emphasis>struct spwd</emphasis>.
<emphasis>getspent</emphasis> returns the next entry from the file,
and <emphasis>fgetspent</emphasis> returns the next entry from the
given stream, which is assumed to be a file of the proper format.
<emphasis>sgetspent</emphasis> returns a pointer to a <emphasis>struct
spwd</emphasis> using the provided string as input.
<emphasis>getspnam</emphasis> searches from the current position in
the file for an entry matching <emphasis>name</emphasis>.
</para>
<para>
<emphasis>setspent</emphasis> and <emphasis>endspent</emphasis> may be
used to begin and end, respectively, access to the shadow password
file.
</para>
<para>
The <emphasis>lckpwdf</emphasis> and <emphasis>ulckpwdf</emphasis>
routines should be used to insure exclusive access to the
<filename>/etc/shadow</filename> file. <emphasis>lckpwdf</emphasis>
attempts to acquire a lock using <emphasis>pw_lock</emphasis> for up
to 15 seconds. It continues by attempting to acquire a second lock
using <emphasis>spw_lock</emphasis> for the remainder of the initial
15 seconds. Should either attempt fail after a total of 15 seconds,
<emphasis>lckpwdf</emphasis> returns -1. When both locks are acquired
0 is returned.
</para>
</refsect1>
<refsect1 id='diagnostics'>
<title>DIAGNOSTICS</title>
<para>
Routines return NULL if no more entries are available or if an error
occurs during processing. Routines which have <emphasis>int</emphasis>
as the return value return 0 for success and
-1 for failure.
</para>
</refsect1>
<refsect1 id='caveats'>
<title>CAVEATS</title>
<para>
These routines may only be used by the superuser as access to the
shadow password file is restricted.
</para>
</refsect1>
<refsect1 id='files'>
<title>FILES</title>
<variablelist>
<varlistentry>
<term><filename>/etc/shadow</filename></term>
<listitem>
<para>Secure user account information.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 id='see_also'>
<title>SEE ALSO</title>
<para>
<citerefentry>
<refentrytitle>getpwent</refentrytitle><manvolnum>3</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>shadow</refentrytitle><manvolnum>5</manvolnum>
</citerefentry>.
</para>
</refsect1>
</refentry>
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