<funcprototype>
<funcdef>int <function>sd_journal_print</function></funcdef>
<paramdef>int <parameter>priority</parameter></paramdef>
- <paramdef>const char
* <parameter>format</parameter></paramdef>
+ <paramdef>const char
*<parameter>format</parameter></paramdef>
<paramdef>...</paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_journal_printv</function></funcdef>
<paramdef>int <parameter>priority</parameter></paramdef>
- <paramdef>const char
* <parameter>format</parameter></paramdef>
+ <paramdef>const char
*<parameter>format</parameter></paramdef>
<paramdef>va_list <parameter>ap</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_journal_send</function></funcdef>
- <paramdef>const char
* <parameter>format</parameter></paramdef>
+ <paramdef>const char
*<parameter>format</parameter></paramdef>
<paramdef>...</paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_journal_perror</function></funcdef>
- <paramdef>const char
* <parameter>message</parameter></paramdef>
+ <paramdef>const char
*<parameter>message</parameter></paramdef>
</funcprototype>
</funcsynopsis>
or
<citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>. The
priority value is one of
- <literal>LOG_EMERG</literal>,
- <literal>LOG_ALERT</literal>,
- <literal>LOG_CRIT</literal>,
- <literal>LOG_ERR</literal>,
- <literal>LOG_WARNING</literal>,
- <literal>LOG_NOTICE</literal>,
- <literal>LOG_INFO</literal>,
- <literal>LOG_DEBUG</literal>, as defined in
+ <constant>LOG_EMERG</constant>,
+ <constant>LOG_ALERT</constant>,
+ <constant>LOG_CRIT</constant>,
+ <constant>LOG_ERR</constant>,
+ <constant>LOG_WARNING</constant>,
+ <constant>LOG_NOTICE</constant>,
+ <constant>LOG_INFO</constant>,
+ <constant>LOG_DEBUG</constant>, as defined in
<filename>syslog.h</filename>, see
<citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
for details. It is recommended to use this call to
<para><function>sd_journal_printv()</function> is
similar to <function>sd_journal_print()</function> but
takes a variable argument list encapsulated in an
- object of type <literal>va_list</literal> (see
+ object of type <varname>va_list</varname> (see
<citerefentry><refentrytitle>stdarg</refentrytitle><manvolnum>3</manvolnum></citerefentry>
for more information) instead of the format string. It
is otherwise equivalent in behavior.</para>
used to submit structured log entries to the system
journal. It takes a series of format strings, each
immediately followed by their associated parameters,
- terminated by NULL. The strings passed should be of
+ terminated by <constant>NULL</constant>. The strings passed should be of
the format <literal>VARIABLE=value</literal>. The
variable name must be in uppercase and consist only of
characters, numbers and underscores, and may not begin
<para><function>sd_journal_sendv()</function> is
similar to <function>sd_journal_send()</function> but
- takes an array of <literal>struct iovec</literal> (as
+ takes an array of <varname>struct iovec</varname> (as
defined in <filename>uio.h</filename>, see
<citerefentry><refentrytitle>readv</refentrytitle><manvolnum>3</manvolnum></citerefentry>
for details) instead of the format string. Each
structure should reference one field of the entry to
submit. The second argument specifies the number of
- structures in the
- array. <function>sd_journal_sendv()</function> is
+ structures in the array.
+ <function>sd_journal_sendv()</function> is
particularly useful to submit binary objects to the
journal where that is necessary.</para>
readable representation of the current error code
stored in
<citerefentry><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>. If
- the message string is passed as NULL or empty string
+ 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 <literal>LOG_ERR</literal> (3).</para>
+ priority used is <constant>LOG_ERR</constant> (3).</para>
<para>Note that <function>sd_journal_send()</function>
is a wrapper around
<para>Note that these calls implicitly add fields for
the source file, function name and code line where
invoked. This is implemented with macros. If this is
- not desired it can be turned off by defining
+ not desired, it can be turned off by defining
SD_JOURNAL_SUPPRESS_LOCATION before including
<filename>sd-journal.h</filename>.</para>
chronological ordering between the two streams cannot
be guaranteed. Using
<function>sd_journal_print()</function> has the
- benefit of logging source code line, file names, and
- functions as meta data along all entries, and
+ benefit of logging source code line, filenames, and
+ functions as metadata along all entries, and
guaranteeing chronological ordering with structured
log entries that are generated via
<function>sd_journal_send()</function>. Using
errno-style error code. The
<citerefentry><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>
variable itself is not altered.</para>
+
+ <para>If
+ <citerefentry><refentrytitle>systemd-journald</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ is not running (the socket is not present), those
+ functions do nothing, and also return 0.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Async signal safety</title>
+ <para><function>sd_journal_sendv()</function> is "async signal
+ safe" in the meaning of <citerefentry><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
+ </para>
+
+ <para><function>sd_journal_print</function>,
+ <function>sd_journal_printv</function>,
+ <function>sd_journal_send</function>, and
+ <function>sd_journal_perror</function> are
+ not async signal safe.</para>
</refsect1>
<refsect1>
<function>sd_journal_printv()</function>,
<function>sd_journal_send()</function> and
<function>sd_journal_sendv()</function> interfaces
- are available as shared library, which can be compiled
+ are available as a shared library, which can be compiled
and linked to with the
- <literal>libsystemd-journal</literal>
- <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ <constant>libsystemd</constant> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
file.</para>
</refsect1>
<citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>perror</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+ <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>socket</refentrytitle><manvolnum>7</manvolnum></citerefentry>
</para>
</refsect1>
~ianmdlvl / elogind.git / blobdiff