+ <para><function>sd_journal_perror()</function> is a
+ similar to
+ <citerefentry><refentrytitle>perror</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ and writes a message to the journal that consists of
+ the passed string, suffixed with ": " and a human
+ readable representation of the current error code
+ stored in
+ <citerefentry><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>. If
+ the message string is passed as <constant>NULL</constant> or empty string,
+ only the error string representation will be written,
+ prefixed with nothing. An additional journal field
+ ERRNO= is included in the entry containing the numeric
+ error code formatted as decimal string. The log
+ priority used is <constant>LOG_ERR</constant> (3).</para>
+