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Diffstat (limited to 'man/sd_journal_open.xml')
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1 files changed, 213 insertions, 227 deletions
diff --git a/man/sd_journal_open.xml b/man/sd_journal_open.xml index 2d1dbc32f8..fb572802a3 100644 --- a/man/sd_journal_open.xml +++ b/man/sd_journal_open.xml @@ -1,6 +1,6 @@ <?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"> + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> <!-- This file is part of systemd. @@ -23,231 +23,217 @@ <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_open_files</refname> - <refname>sd_journal_open_container</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> - - <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_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>int <function>sd_journal_open_container</function></funcdef> - <paramdef>sd_journal **<parameter>ret</parameter></paramdef> - <paramdef>const char *<parameter>machine</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> - </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 <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: - <constant>SD_JOURNAL_LOCAL_ONLY</constant> makes sure - only journal files generated on the local machine will - be opened. <constant>SD_JOURNAL_RUNTIME_ONLY</constant> - makes sure only volatile journal files will be opened, - 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> - 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_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><function>sd_journal_open_container()</function> - is similar to <function>sd_journal_open()</function> - but opens the journal files of a running - OS container. The specified machine name refers to a - container that is registered with - <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</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 - <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 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>, - <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> - </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 a shared library, which can be compiled and - linked to with the - <constant>libsystemd</constant> <citerefentry project='die-net'><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> - - <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>, - <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry> - </para> - </refsect1> + <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_open_files</refname> + <refname>sd_journal_open_container</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> + + <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_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>int <function>sd_journal_open_container</function></funcdef> + <paramdef>sd_journal **<parameter>ret</parameter></paramdef> + <paramdef>const char *<parameter>machine</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> + </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 <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: <constant>SD_JOURNAL_LOCAL_ONLY</constant> + makes sure only journal files generated on the local machine will + be opened. <constant>SD_JOURNAL_RUNTIME_ONLY</constant> makes sure + only volatile journal files will be opened, 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> 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_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><function>sd_journal_open_container()</function> is similar + to <function>sd_journal_open()</function> but opens the journal + files of a running OS container. The specified machine name refers + to a container that is registered with + <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</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 + <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 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>, + <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> + </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 a shared library, which can be compiled and linked to with the + <constant>libsystemd</constant> <citerefentry project='die-net'><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> + + <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>, + <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry> + </para> + </refsect1> </refentry> |