- <para>These prefixes are intended to be used in
- conjunction with STDERR-based logging as implemented
- by systemd. If a systemd service definition file is
- configured with <varname>StandardError=syslog</varname>
- or <varname>StandardError=kmsg</varname> these
- prefixes can be used to encode a log level in lines
- printed. This is similar to the kernel
- <function>printk()</function>-style logging. See
- <citerefentry><refentrytitle>klogctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- for more information.</para>
-
- <para>The log levels are identical to
- <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>'s
- log level system. To use these prefixes simply prefix
- every line with one of these strings. A line that is
- not prefixed will be logged at the default log level
- SD_INFO.</para>
-
- <example>
- <title>Hello World</title>
-
- <para>A daemon may log with the log level
- NOTICE by issuing this call:</para>
-
- <programlisting>fprintf(stderr, SD_NOTICE "Hello World!\n");</programlisting>
- </example>
- </refsect1>
-
- <refsect1>
- <title>Notes</title>
-
- <para>These interfaces are provided by the reference
- implementation of APIs for new-style daemons and
- distributed with the systemd package. The algorithms
- they implement are simple, and can easily be
- reimplemented in daemons if it is important to support
- this interface without using the reference
- implementation. See the respective function man pages
- for details.</para>
-
- <para>In addition, for details about the algorithms
- check the liberally licensed reference implementation
- sources:
- <ulink url="http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.c"/>
- resp. <ulink url="http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.h"/></para>
-
- <para>These APIs are 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,
- either verbatim or in excerpts.</para>
-
- <para>The functions directly related to new-style
- daemons become NOPs when -DDISABLE_SYSTEMD is set
- during compilation and the reference implementation is
- used as drop-in files. In addition, if
- <filename>sd-daemon.c</filename> is compiled on
- non-Linux systems they become NOPs.</para>
- </refsect1>
-
- <refsect1>
- <title>See Also</title>
- <para>
- <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>sd_booted</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>sd_is_fifo</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>fprintf</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>sd-readahead</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
- </para>
- </refsect1>
+ <para>These prefixes are intended to be used in conjunction with
+ stderr-based logging as implemented by systemd. If a systemd
+ service definition file is configured with
+ <varname>StandardError=journal</varname>,
+ <varname>StandardError=syslog</varname> or
+ <varname>StandardError=kmsg</varname>, these prefixes can be used
+ to encode a log level in lines printed. This is similar to the
+ kernel <function>printk()</function>-style logging. See
+ <citerefentry><refentrytitle>klogctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for more information.</para>
+
+ <para>The log levels are identical to
+ <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>'s
+ log level system. To use these prefixes simply prefix every line
+ with one of these strings. A line that is not prefixed will be
+ logged at the default log level SD_INFO.</para>
+
+ <example>
+ <title>Hello World</title>
+
+ <para>A daemon may log with the log level NOTICE by issuing this
+ call:</para>
+
+ <programlisting>fprintf(stderr, SD_NOTICE "Hello World!\n");</programlisting>
+ </example>
+ </refsect1>
+
+ <xi:include href="libsystemd-pkgconfig.xml" />
+
+ <refsect1>
+ <title>See Also</title>
+ <para>
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_booted</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_is_fifo</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_watchdog_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry project='man-pages'><refentrytitle>fprintf</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ </para>
+ </refsect1>