<refnamediv>
<refname>sd_journal_open</refname>
<refname>sd_journal_open_directory</refname>
+ <refname>sd_journal_open_files</refname>
<refname>sd_journal_close</refname>
+ <refname>sd_journal</refname>
+ <refname>SD_JOURNAL_LOCAL_ONLY</refname>
+ <refname>SD_JOURNAL_RUNTIME_ONLY</refname>
+ <refname>SD_JOURNAL_SYSTEM</refname>
+ <refname>SD_JOURNAL_CURRENT_USER</refname>
<refpurpose>Open the system journal for reading</refpurpose>
</refnamediv>
</funcprototype>
<funcprototype>
- <funcdef>int <function>sd_journal_close</function></funcdef>
+ <funcdef>int <function>sd_journal_open_files</function></funcdef>
+ <paramdef>sd_journal** <parameter>ret</parameter></paramdef>
+ <paramdef>const char** <parameter>paths</parameter></paramdef>
+ <paramdef>int <parameter>flags</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>void <function>sd_journal_close</function></funcdef>
<paramdef>sd_journal* <parameter>j</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<refsect1>
<title>Description</title>
- <para><function>sd_journal_open()</function> opens the
+ <para><function>sd_journal_open()</function> opens
the log journal for reading. It will find all journal
files automatically and interleave them automatically
when reading. As first argument it takes a pointer to
- a <literal>sd_journal</literal> pointer, which on
- success will contain journal context afterwards. The
+ a <varname>sd_journal</varname> pointer, which on
+ success will contain a journal context object. The
second argument is a flags field, which may consist of
the following flags ORed together:
- <literal>SD_JOURNAL_LOCAL_ONLY</literal> makes sure
+ <constant>SD_JOURNAL_LOCAL_ONLY</constant> makes sure
only journal files generated on the local machine will
- be opened. <literal>SD_JOURNAL_RUNTIME_ONLY</literal>
+ be opened. <constant>SD_JOURNAL_RUNTIME_ONLY</constant>
makes sure only volatile journal files will be opened,
- excluding those which are stored on persistant
- storage. <literal>SD_JOURNAL_SYSTEM_ONLY</literal>
- will ensure that only journal files of system services
- and the kernel (in opposition to user session processes) will
- be opened.</para>
+ excluding those which are stored on persistent
+ storage. <constant>SD_JOURNAL_SYSTEM</constant>
+ will cause journal files of system services and the
+ kernel (in opposition to user session processes) to
+ be opened. <constant>SD_JOURNAL_CURRENT_USER</constant>
+ will cause journal files of the current user to be
+ opened. If neither <constant>SD_JOURNAL_SYSTEM</constant>
+ nor <constant>SD_JOURNAL_CURRENT_USER</constant> are
+ specified, all journal file types will be opened.</para>
<para><function>sd_journal_open_directory()</function>
is similar to <function>sd_journal_open()</function>
flags argument, but it must be passed as 0 as no flags
are currently understood for this call.</para>
+ <para><function>sd_journal_open_files()</function>
+ is similar to <function>sd_journal_open()</function>
+ but takes a <constant>NULL</constant>-terminated list
+ of file paths to open. All files will be opened and
+ interleaved automatically. This call also takes a
+ flags argument, but it must be passed as 0 as no flags
+ are currently understood for this call. Please note
+ that in the case of a live journal, this function is only
+ useful for debugging, because individual journal files
+ can be rotated at any moment, and the opening of
+ specific files is inherently racy.</para>
+
+ <para><varname>sd_journal</varname> objects cannot be
+ used in the child after a fork. Functions which take a
+ journal object as an argument
+ (<function>sd_journal_next()</function> and others)
+ will return <constant>-ECHILD</constant> after a fork.
+ </para>
+
<para><function>sd_journal_close()</function> will
close the journal context allocated with
<function>sd_journal_open()</function> or
<para>See
<citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- for an example how to iterate through the journal
- after opening it it with
+ for an example of how to iterate through the journal
+ after opening it with
<function>sd_journal_open()</function>.</para>
+
+ <para>A journal context object returned by
+ <function>sd_journal_open()</function> references a
+ specific journal entry as <emphasis>current</emphasis> entry,
+ similar to a file seek index in a classic file system
+ file, but without absolute positions. It may be
+ altered with
+ <citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ and
+ <citerefentry><refentrytitle>sd_journal_seek_head</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ and related calls. The current entry position may be
+ exported in <emphasis>cursor</emphasis> strings, as accessible
+ via
+ <citerefentry><refentrytitle>sd_journal_get_cursor</refentrytitle><manvolnum>3</manvolnum></citerefentry>. Cursor
+ strings may be used to globally identify a specific
+ journal entry in a stable way and then later to seek
+ to it (or if the specific entry is not available
+ locally, to its closest entry in time)
+ <citerefentry><refentrytitle>sd_journal_seek_cursor</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
+
+ <para>Notification of journal changes is available via
+ <function>sd_journal_get_fd()</function> and related
+ calls.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
- <para>The <function>sd_journal_open()</function> and
- <function>sd_journal_open_directory()</function> calls
+ <para>The <function>sd_journal_open()</function>,
+ <function>sd_journal_open_directory()</function>, and
+ <function>sd_journal_open_files()</function> calls
return 0 on success or a negative errno-style error
code. <function>sd_journal_close()</function> returns
nothing.</para>
<para>The <function>sd_journal_open()</function>,
<function>sd_journal_open_directory()</function> and
<function>sd_journal_close()</function> interfaces are
- available as shared library, which can be compiled and
+ 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-journal</constant> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
file.</para>
</refsect1>
+ <refsect1>
+ <title>History</title>
+
+ <para><function>sd_journal_open()</function>,
+ <function>sd_journal_close()</function>,
+ <constant>SD_JOURNAL_LOCAL_ONLY</constant>,
+ <constant>SD_JOURNAL_RUNTIME_ONLY</constant>,
+ <constant>SD_JOURNAL_SYSTEM_ONLY</constant> were added
+ in systemd-38.</para>
+
+ <para><function>sd_journal_open_directory()</function>
+ was added in systemd-187.</para>
+
+ <para><constant>SD_JOURNAL_SYSTEM</constant>,
+ <constant>SD_JOURNAL_CURRENT_USER</constant>,
+ and <function>sd_journal_open_files()</function>
+ were added in systemd-205.
+ <constant>SD_JOURNAL_SYSTEM_ONLY</constant>
+ was deprecated.</para>
+ </refsect1>
+
<refsect1>
<title>See Also</title>