<refname>sd_login_monitor_get_events</refname>
<refname>sd_login_monitor_get_timeout</refname>
<refname>sd_login_monitor</refname>
- <refpurpose>Monitor login sessions, seats and users</refpurpose>
+ <refpurpose>Monitor login sessions, seats, users and virtual machines/containers</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Description</title>
<para><function>sd_login_monitor_new()</function> may
- be used to monitor login sessions, users and seats. Via
- a monitor object a file descriptor can be integrated
- into an application defined event loop which is woken
- up each time a user logs in, logs out or a seat is
- added or removed, or a session, user, or seat changes
- state otherwise. The first parameter takes a string
- which can be <literal>seat</literal> (to get
+ be used to monitor login sessions, users, seats, and
+ virtual machines/containers. Via a monitor object a
+ file descriptor can be integrated into an application
+ defined event loop which is woken up each time a user
+ logs in, logs out or a seat is added or removed, or a
+ session, user, seat or virtual machine/container
+ changes state otherwise. The first parameter takes a
+ string which can be <literal>seat</literal> (to get
only notifications about seats being added, removed or
changed), <literal>session</literal> (to get only
notifications about sessions being created or removed
- or changed) or <literal>uid</literal> (to get only
+ or changed), <literal>uid</literal> (to get only
notifications when a user changes state in respect to
- logins). If notifications shall be generated in all
- these conditions, NULL may be passed. Note that in the
- future additional categories may be defined. The
- second parameter returns a monitor object and needs to
- be freed with the
+ logins) or <literal>machine</literal> (to get only
+ notifications when a virtual machine or container is
+ started or stopped). If notifications shall be
+ generated in all these conditions, <constant>NULL</constant> may be
+ passed. Note that in the future additional categories
+ may be defined. The second parameter returns a monitor
+ object and needs to be freed with the
<function>sd_login_monitor_unref()</function> call
after use.</para>
object. Whenever an event causes the monitor to wake
up the event loop via the file descriptor this
function needs to be called to reset the wake-up
- state. If this call is not invoked the file descriptor
+ state. If this call is not invoked, the file descriptor
will immediately wake up the event loop again.</para>
<para><function>sd_login_monitor_get_fd()</function>
<para><function>sd_login_monitor_get_events()</function>
will return the <function>poll()</function> mask to
wait for. This function will return a combination of
- <literal>POLLIN</literal>, <literal>POLLOUT</literal>
+ <constant>POLLIN</constant>, <constant>POLLOUT</constant>
and similar to fill into the
- <literal>.events</literal> field of <literal>struct
- pollfd</literal>.</para>
+ <literal>.events</literal> field of <varname>struct
+ pollfd</varname>.</para>
<para><function>sd_login_monitor_get_timeout()</function>
will return a timeout value for usage in
<function>poll()</function>. This returns a value in
- microseconds since the epoch of CLOCK_MONOTONIC for
- timing out <function>poll()</function> in
- <literal>timeout_usec</literal>. See
+ microseconds since the epoch of <constant>CLOCK_MONOTONIC</constant>
+ for timing out <function>poll()</function> in
+ <varname>timeout_usec</varname>. See
<citerefentry><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>
for details about
- <literal>CLOCK_MONOTONIC</literal>. If there's no
+ <constant>CLOCK_MONOTONIC</constant>. If there is no
timeout to wait for this will fill in
- <literal>(uint64_t) -1</literal> instead. Note that
+ <constant>(uint64_t) -1</constant> instead. Note that
<function>poll()</function> takes a relative timeout
in milliseconds rather than an absolute timeout in
microseconds. To convert the absolute 'us' timeout into
}</programlisting>
<para>The code above does not do any error checking
- for brevity's sake. The calculated <literal>msec</literal>
+ for brevity's sake. The calculated <varname>msec</varname>
integer can be passed directly as
<function>poll()</function>'s timeout
parameter.</para>
<refsect1>
<title>Return Value</title>
- <para>On success
+ <para>On success,
<function>sd_login_monitor_new()</function>,
<function>sd_login_monitor_flush()</function> and
<function>sd_login_monitor_get_timeout()</function>
- return 0 or a positive integer. On success
+ return 0 or a positive integer. On success,
<function>sd_login_monitor_get_fd()</function> returns
- a Unix file descriptor. On success
+ a Unix file descriptor. On success,
<function>sd_login_monitor_get_events()</function>
- returns a combination of <literal>POLLIN</literal>,
- <literal>POLLOUT</literal> and suchlike. On failure,
+ returns a combination of <constant>POLLIN</constant>,
+ <constant>POLLOUT</constant> and suchlike. On failure,
these calls return a negative errno-style error
code.</para>
<para><function>sd_login_monitor_unref()</function>
- always returns NULL.</para>
+ always returns <constant>NULL</constant>.</para>
</refsect1>
<refsect1>
<function>sd_login_monitor_get_fd()</function>,
<function>sd_login_monitor_get_events()</function> and
<function>sd_login_monitor_get_timeout()</function>
- interfaces are available as shared library, which can
+ interfaces are available as a shared library, which can
be compiled and linked to with the
- <literal>libsystemd-login</literal>
- <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ <constant>libsystemd-login</constant> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
file.</para>
</refsect1>
~ianmdlvl / elogind.git / blobdiff