- <filename>/sys/fs/cgroup/systemd</filename> virtual file
- system is mounted, by comparing the st_dev value of
- the <function>stat()</function> data of
- <filename>/sys/fs/cgroup</filename> and
- <filename>/sys/fs/cgroup/systemd</filename>.</para>
-
- <para>For details about the algorithm check the
- liberally licensed reference implementation sources:
- <ulink url="http://cgit.freedesktop.org/systemd/systemd/plain/src/sd-daemon.c"/>
- resp. <ulink
- url="http://cgit.freedesktop.org/systemd/systemd/plain/src/systemd/sd-daemon.h"/></para>
-
- <para><function>sd_booted()</function> is implemented
- in the reference implementation's
- <filename>sd-daemon.c</filename> and
- <filename>sd-daemon.h</filename> files. These
- interfaces are available as shared library, which can
- be compiled and linked to with the
- <literal>libsystemd-daemon</literal>
- <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
- file. Alternatively, applications consuming these APIs
- may copy the implementation into their source
- tree. For more details about the reference
- implementation see
- <citerefentry><refentrytitle>sd_daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
-
- <para>If the reference implementation is used as
- drop-in files and -DDISABLE_SYSTEMD is set during
- compilation this function will always return 0 and
- otherwise become a NOP.</para>