diff options
Diffstat (limited to 'man/sd_journal_open.xml')
| -rw-r--r-- | man/sd_journal_open.xml | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/man/sd_journal_open.xml b/man/sd_journal_open.xml new file mode 100644 index 0000000000..06d0ccfd12 --- /dev/null +++ b/man/sd_journal_open.xml @@ -0,0 +1,184 @@ +<?xml version='1.0'?> <!--*-nxml-*--> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> + +<!-- + This file is part of systemd. + + Copyright 2012 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +--> + +<refentry id="sd_journal_open"> + + <refentryinfo> + <title>sd_journal_open</title> + <productname>systemd</productname> + + <authorgroup> + <author> + <contrib>Developer</contrib> + <firstname>Lennart</firstname> + <surname>Poettering</surname> + <email>lennart@poettering.net</email> + </author> + </authorgroup> + </refentryinfo> + + <refmeta> + <refentrytitle>sd_journal_open</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_journal_open</refname> + <refname>sd_journal_open_directory</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_ONLY</refname> + <refpurpose>Open the system journal for reading</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-journal.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_journal_open</function></funcdef> + <paramdef>sd_journal** <parameter>ret</parameter></paramdef> + <paramdef>int <parameter>flags</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_journal_open_directory</function></funcdef> + <paramdef>sd_journal** <parameter>ret</parameter></paramdef> + <paramdef>const char* <parameter>path</parameter></paramdef> + <paramdef>int <parameter>flags</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_journal_close</function></funcdef> + <paramdef>sd_journal* <parameter>j</parameter></paramdef> + </funcprototype> + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <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 object afterwards. The + second argument is a flags field, which may consist of + the following flags ORed together: + <literal>SD_JOURNAL_LOCAL_ONLY</literal> makes sure + only journal files generated on the local machine will + be opened. <literal>SD_JOURNAL_RUNTIME_ONLY</literal> + makes sure only volatile journal files will be opened, + excluding those which are stored on persistent + 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> + + <para><function>sd_journal_open_directory()</function> + is similar to <function>sd_journal_open()</function> + but takes an absolute directory path as argument. All + journal files in this directory 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.</para> + + <para><function>sd_journal_close()</function> will + close the journal context allocated with + <function>sd_journal_open()</function> or + <function>sd_journal_open_directory()</function> and + free its resources.</para> + + <para>When opening the journal only journal files + accessible to the calling user will be opened. If + journal files are not accessible to the caller this + will be silently ignored.</para> + + <para>See + <citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry> + for an example 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 + return 0 on success or a negative errno-style error + code. <function>sd_journal_close()</function> returns + nothing.</para> + </refsect1> + + <refsect1> + <title>Notes</title> + + <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 + linked to with the + <literal>libsystemd-journal</literal> + <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> + file.</para> + </refsect1> + + <refsect1> + <title>See Also</title> + + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_journal_get_data</refentrytitle><manvolnum>3</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |