| <?xml version='1.0'?> <!--*-nxml-*--> |
| <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" |
| "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> |
| <!-- SPDX-License-Identifier: LGPL-2.1-or-later --> |
| |
| <refentry id="sd_uid_get_state" conditional='HAVE_PAM' |
| xmlns:xi="http://www.w3.org/2001/XInclude"> |
| |
| <refentryinfo> |
| <title>sd_uid_get_state</title> |
| <productname>systemd</productname> |
| </refentryinfo> |
| |
| <refmeta> |
| <refentrytitle>sd_uid_get_state</refentrytitle> |
| <manvolnum>3</manvolnum> |
| </refmeta> |
| |
| <refnamediv> |
| <refname>sd_uid_get_state</refname> |
| <refname>sd_uid_is_on_seat</refname> |
| <refname>sd_uid_get_sessions</refname> |
| <refname>sd_uid_get_seats</refname> |
| <refname>sd_uid_get_display</refname> |
| <refpurpose>Determine login state of a specific Unix user ID</refpurpose> |
| </refnamediv> |
| |
| <refsynopsisdiv> |
| <funcsynopsis> |
| <funcsynopsisinfo>#include <systemd/sd-login.h></funcsynopsisinfo> |
| |
| <funcprototype> |
| <funcdef>int <function>sd_uid_get_state</function></funcdef> |
| <paramdef>uid_t <parameter>uid</parameter></paramdef> |
| <paramdef>char **<parameter>state</parameter></paramdef> |
| </funcprototype> |
| |
| <funcprototype> |
| <funcdef>int <function>sd_uid_is_on_seat</function></funcdef> |
| <paramdef>uid_t <parameter>uid</parameter></paramdef> |
| <paramdef>int <parameter>require_active</parameter></paramdef> |
| <paramdef>const char *<parameter>seat</parameter></paramdef> |
| </funcprototype> |
| |
| <funcprototype> |
| <funcdef>int <function>sd_uid_get_sessions</function></funcdef> |
| <paramdef>uid_t <parameter>uid</parameter></paramdef> |
| <paramdef>int <parameter>require_active</parameter></paramdef> |
| <paramdef>char ***<parameter>sessions</parameter></paramdef> |
| </funcprototype> |
| |
| <funcprototype> |
| <funcdef>int <function>sd_uid_get_seats</function></funcdef> |
| <paramdef>uid_t <parameter>uid</parameter></paramdef> |
| <paramdef>int <parameter>require_active</parameter></paramdef> |
| <paramdef>char ***<parameter>seats</parameter></paramdef> |
| </funcprototype> |
| |
| <funcprototype> |
| <funcdef>int <function>sd_uid_get_display</function></funcdef> |
| <paramdef>uid_t <parameter>uid</parameter></paramdef> |
| <paramdef>char **<parameter>session</parameter></paramdef> |
| </funcprototype> |
| </funcsynopsis> |
| </refsynopsisdiv> |
| |
| <refsect1> |
| <title>Description</title> |
| |
| <para><function>sd_uid_get_state()</function> may be used to |
| determine the login state of a specific Unix user identifier. The |
| following states are currently known: <literal>offline</literal> |
| (user not logged in at all), <literal>lingering</literal> (user |
| not logged in, but some user services running), |
| <literal>online</literal> (user logged in, but not active, i.e. |
| has no session in the foreground), <literal>active</literal> (user |
| logged in, and has at least one active session, i.e. one session |
| in the foreground), <literal>closing</literal> (user not logged |
| in, and not lingering, but some processes are still around). In |
| the future additional states might be defined, client code should |
| be written to be robust in regards to additional state strings |
| being returned. The returned string needs to be freed with the |
| libc |
| <citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry> |
| call after use.</para> |
| |
| <para><function>sd_uid_is_on_seat()</function> may be used to |
| determine whether a specific user is logged in or active on a |
| specific seat. Accepts a Unix user identifier and a seat |
| identifier string as parameters. The |
| <parameter>require_active</parameter> parameter is a boolean |
| value. If non-zero (true), this function will test if the user is |
| active (i.e. has a session that is in the foreground and accepting |
| user input) on the specified seat, otherwise (false) only if the |
| user is logged in (and possibly inactive) on the specified |
| seat.</para> |
| |
| <para><function>sd_uid_get_sessions()</function> may be used to |
| determine the current sessions of the specified user. Accepts a |
| Unix user identifier as parameter. The |
| <parameter>require_active</parameter> parameter controls whether |
| the returned list shall consist of only those sessions where the |
| user is currently active (> 0), where the user is currently |
| online but possibly inactive (= 0), or logged in but |
| possibly closing the session (< 0). The call returns a |
| <constant>NULL</constant> terminated string array of session |
| identifiers in <parameter>sessions</parameter> which needs to be |
| freed by the caller with the libc |
| <citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry> |
| call after use, including all the strings referenced. If the |
| string array parameter is passed as <constant>NULL</constant>, the |
| array will not be filled in, but the return code still indicates |
| the number of current sessions. Note that instead of an empty |
| array <constant>NULL</constant> may be returned and should be |
| considered equivalent to an empty array.</para> |
| |
| <para>Similarly, <function>sd_uid_get_seats()</function> may be |
| used to determine the list of seats on which the user currently |
| has sessions. Similar semantics apply, however note that the user |
| may have multiple sessions on the same seat as well as sessions |
| with no attached seat and hence the number of entries in the |
| returned array may differ from the one returned by |
| <function>sd_uid_get_sessions()</function>.</para> |
| |
| <para><function>sd_uid_get_display()</function> returns the name |
| of the "primary" session of a user. If the user has graphical |
| sessions, it will be the oldest graphical session. Otherwise, it |
| will be the oldest open session.</para> |
| </refsect1> |
| |
| <refsect1> |
| <title>Return Value</title> |
| |
| <para>On success, <function>sd_uid_get_state()</function> returns 0 or a positive integer. If the test |
| succeeds, <function>sd_uid_is_on_seat()</function> returns a positive integer; if it fails, 0. |
| <function>sd_uid_get_sessions()</function> and <function>sd_uid_get_seats()</function> return the number |
| of entries in the returned arrays. <function>sd_uid_get_display()</function> returns a non-negative code |
| on success. On failure, these calls return a negative errno-style error code.</para> |
| |
| <refsect2> |
| <title>Errors</title> |
| |
| <para>Returned errors may indicate the following problems:</para> |
| |
| <variablelist> |
| |
| <varlistentry> |
| <term><constant>-ENODATA</constant></term> |
| |
| <listitem><para>The given field is not specified for the described user.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><constant>-ENXIO</constant></term> |
| |
| <listitem><para>The specified seat is unknown.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><constant>-EINVAL</constant></term> |
| |
| <listitem><para>An input parameter was invalid (out of range, or <constant>NULL</constant>, |
| where that is not accepted). This is also returned if the passed user ID is |
| <constant>0xFFFF</constant> or <constant>0xFFFFFFFF</constant>, which are undefined on Linux. |
| </para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><constant>-ENOMEM</constant></term> |
| |
| <listitem><para>Memory allocation failed.</para></listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect2> |
| </refsect1> |
| |
| <xi:include href="libsystemd-pkgconfig.xml" /> |
| |
| <refsect1> |
| <title>See Also</title> |
| |
| <para> |
| <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>sd-login</refentrytitle><manvolnum>3</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>sd_pid_get_owner_uid</refentrytitle><manvolnum>3</manvolnum></citerefentry> |
| </para> |
| </refsect1> |
| |
| </refentry> |
