"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
- <refentry id="journalctl"
- xmlns:xi="http://www.w3.org/2001/XInclude">
-
- <refentryinfo>
- <title>journalctl</title>
- <productname>systemd</productname>
- </refentryinfo>
-
- <refmeta>
- <refentrytitle>journalctl</refentrytitle>
- <manvolnum>1</manvolnum>
- </refmeta>
-
- <refnamediv>
- <refname>journalctl</refname>
- <refpurpose>Query the systemd journal</refpurpose>
- </refnamediv>
-
- <refsynopsisdiv>
- <cmdsynopsis>
- <command>journalctl</command>
- <arg choice="opt" rep="repeat">OPTIONS</arg>
- <arg choice="opt" rep="repeat">MATCHES</arg>
- </cmdsynopsis>
- </refsynopsisdiv>
-
- <refsect1>
- <title>Description</title>
-
- <para><command>journalctl</command> may be used to query the
- contents of the
- <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
- journal as written by
- <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
-
- <para>If called without parameters, it will show the full
- contents of the journal, starting with the oldest entry
- collected.</para>
-
- <para>If one or more match arguments are passed, the output is
- filtered accordingly. A match is in the format
- <literal>FIELD=VALUE</literal>,
- e.g. <literal>_SYSTEMD_UNIT=httpd.service</literal>, referring
- to the components of a structured journal entry. See
- <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
- for a list of well-known fields. If multiple matches are
- specified matching different fields, the log entries are
- filtered by both, i.e. the resulting output will show only
- entries matching all the specified matches of this kind. If two
- matches apply to the same field, then they are automatically
- matched as alternatives, i.e. the resulting output will show
- entries matching any of the specified matches for the same
- field. Finally, the character <literal>+</literal> may appear
- as a separate word between other terms on the command line. This
- causes all matches before and after to be combined in a
- disjunction (i.e. logical OR).</para>
-
- <para>It is also possible to filter the entries by specifying an
- absolute file path as an argument. The file path may be a file or
- a symbolic link and the file must exist at the time of the query. If a
- file path refers to an executable binary, an <literal>_EXE=</literal>
- match for the canonicalized binary path is added to the query. If a
- file path refers to an executable script, a <literal>_COMM=</literal>
- match for the script name is added to the query. If a file path
- refers to a device node, <literal>_KERNEL_DEVICE=</literal> matches for
- the kernel name of the device and for each of its ancestor devices is
- added to the query. Symbolic links are dereferenced, kernel names are
- synthesized, and parent devices are identified from the environment at
- the time of the query. In general, a device node is the best proxy for
- an actual device, as log entries do not usually contain fields that
- identify an actual device. For the resulting log entries to be correct
- for the actual device, the relevant parts of the environment at the time
- the entry was logged, in particular the actual device corresponding to
- the device node, must have been the same as those at the time of the
- query. Because device nodes generally change their corresponding devices
- across reboots, specifying a device node path causes the resulting
- entries to be restricted to those from the current boot.</para>
-
- <para>Additional constraints may be added using options
- <option>--boot</option>, <option>--unit=</option>, etc., to
- further limit what entries will be shown (logical AND).</para>
-
- <para>Output is interleaved from all accessible journal files, whether they are rotated or currently
- being written, and regardless of whether they belong to the system itself or are accessible user
- journals. The <option>--header</option> option can be used to identify which files
- <emphasis>are</emphasis> being shown.</para>
-
- <para>The set of journal files which will be used can be
- modified using the <option>--user</option>,
- <option>--system</option>, <option>--directory</option>, and
- <option>--file</option> options, see below.</para>
-
- <para>All users are granted access to their private per-user
- journals. However, by default, only root and users who are
- members of a few special groups are granted access to the system
- journal and the journals of other users. Members of the groups
- <literal>systemd-journal</literal>, <literal>adm</literal>, and
- <literal>wheel</literal> can read all journal files. Note
- that the two latter groups traditionally have additional
- privileges specified by the distribution. Members of the
- <literal>wheel</literal> group can often perform administrative
- tasks.</para>
-
- <para>The output is paged through <command>less</command> by
- default, and long lines are "truncated" to screen width. The
- hidden part can be viewed by using the left-arrow and
- right-arrow keys. Paging can be disabled; see the
- <option>--no-pager</option> option and the "Environment" section
- below.</para>
-
- <para>When outputting to a tty, lines are colored according to
- priority: lines of level ERROR and higher are colored red; lines
- of level NOTICE and higher are highlighted; lines of level DEBUG
- are colored lighter grey; other lines are displayed normally.</para>
- </refsect1>
-
- <refsect1>
- <title>Options</title>
-
- <para>The following options are understood:</para>
-
- <variablelist>
- <varlistentry>
- <term><option>--no-full</option></term>
- <term><option>--full</option></term>
- <term><option>-l</option></term>
-
- <listitem><para>Ellipsize fields when they do not fit in
- available columns. The default is to show full fields,
- allowing them to wrap or be truncated by the pager, if one
- is used.</para>
-
- <para>The old options
- <option>-l</option>/<option>--full</option> are not useful
- anymore, except to undo <option>--no-full</option>.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>-a</option></term>
- <term><option>--all</option></term>
-
- <listitem><para>Show all fields in full, even if they include unprintable characters or are very long. By
- default, fields with unprintable characters are abbreviated as "blob data". (Note that the pager may escape
- unprintable characters again.)</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>-f</option></term>
- <term><option>--follow</option></term>
-
- <listitem><para>Show only the most recent journal entries,
- and continuously print new entries as they are appended to
- the journal.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>-e</option></term>
- <term><option>--pager-end</option></term>
-
- <listitem><para>Immediately jump to the end of the journal
- inside the implied pager tool. This implies
- <option>-n1000</option> to guarantee that the pager will not
- buffer logs of unbounded size. This may be overridden with
- an explicit <option>-n</option> with some other numeric
- value, while <option>-nall</option> will disable this cap.
- Note that this option is only supported for the
- <citerefentry project='man-pages'><refentrytitle>less</refentrytitle><manvolnum>1</manvolnum></citerefentry>
- pager.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>-n</option></term>
- <term><option>--lines=</option></term>
-
- <listitem><para>Show the most recent journal events and
- limit the number of events shown. If
- <option>--follow</option> is used, this option is
- implied. The argument is a positive integer or
- <literal>all</literal> to disable line limiting. The default
- value is 10 if no argument is given.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>--no-tail</option></term>
-
- <listitem><para>Show all stored output lines, even in follow
- mode. Undoes the effect of <option>--lines=</option>.
- </para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>-r</option></term>
- <term><option>--reverse</option></term>
-
- <listitem><para>Reverse output so that the newest entries
- are displayed first.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>-o</option></term>
- <term><option>--output=</option></term>
-
- <listitem><para>Controls the formatting of the journal
- entries that are shown. Takes one of the following
- options:</para>
- <variablelist>
- <varlistentry>
- <term>
- <option>short</option>
- </term>
- <listitem>
- <para>is the default and generates an output that is
- mostly identical to the formatting of classic syslog
- files, showing one line per journal entry.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <option>short-full</option>
- </term>
- <listitem>
- <para>is very similar, but shows timestamps in the format the <option>--since=</option> and
- <option>--until=</option> options accept. Unlike the timestamp information shown in
- <option>short</option> output mode this mode includes weekday, year and timezone information in the
- output, and is locale-independent.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <option>short-iso</option>
- </term>
- <listitem>
- <para>is very similar, but shows ISO 8601 wallclock
- timestamps.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <option>short-iso-precise</option>
- </term>
- <listitem>
- <para>as for <option>short-iso</option> but includes full
- microsecond precision.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <option>short-precise</option>
- </term>
- <listitem>
- <para>is very similar, but shows classic syslog timestamps
- with full microsecond precision.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <option>short-monotonic</option>
- </term>
- <listitem>
- <para>is very similar, but shows monotonic timestamps
- instead of wallclock timestamps.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <option>short-unix</option>
- </term>
- <listitem>
- <para>is very similar, but shows seconds passed since January 1st 1970 UTC instead of wallclock
- timestamps ("UNIX time"). The time is shown with microsecond accuracy.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <option>verbose</option>
- </term>
- <listitem>
- <para>shows the full-structured entry items with all
- fields.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <option>export</option>
- </term>
- <listitem>
- <para>serializes the journal into a binary (but mostly
- text-based) stream suitable for backups and network
- transfer (see
- <ulink url="https://systemd.io/JOURNAL_EXPORT_FORMATS#journal-export-format">Journal Export Format</ulink>
- for more information). To import the binary stream back
- into native journald format use
- <citerefentry><refentrytitle>systemd-journal-remote</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <option>json</option>
- </term>
- <listitem>
- <para>formats entries as JSON objects, separated by newline characters (see <ulink
- url="https://systemd.io/JOURNAL_EXPORT_FORMATS#journal-json-format">Journal JSON Format</ulink> for more
- information). Field values are generally encoded as JSON strings, with three exceptions:
- <orderedlist>
- <listitem><para>Fields larger than 4096 bytes are encoded as <constant>null</constant> values. (This
- may be turned off by passing <option>--all</option>, but be aware that this may allocate overly long
- JSON objects.) </para></listitem>
-
- <listitem><para>Journal entries permit non-unique fields within the same log entry. JSON does not allow
- non-unique fields within objects. Due to this, if a non-unique field is encountered a JSON array is
- used as field value, listing all field values as elements.</para></listitem>
-
- <listitem><para>Fields containing non-printable or non-UTF8 bytes are encoded as arrays containing
- the raw bytes individually formatted as unsigned numbers.</para></listitem>
- </orderedlist>
-
- Note that this encoding is reversible (with the exception of the size limit).</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <option>json-pretty</option>
- </term>
- <listitem>
- <para>formats entries as JSON data structures, but
- formats them in multiple lines in order to make them
- more readable by humans.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <option>json-sse</option>
- </term>
- <listitem>
- <para>formats entries as JSON data structures, but wraps
- them in a format suitable for
- <ulink url="https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">Server-Sent Events</ulink>.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <option>json-seq</option>
- </term>
- <listitem>
- <para>formats entries as JSON data structures, but prefixes them with an ASCII Record Separator
- character (0x1E) and suffixes them with an ASCII Line Feed character (0x0A), in accordance with <ulink
- url="https://tools.ietf.org/html/rfc7464">JavaScript Object Notation (JSON) Text Sequences </ulink>
- (<literal>application/json-seq</literal>).
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <option>cat</option>
- </term>
- <listitem>
- <para>generates a very terse output, only showing the actual message of each journal entry
- with no metadata, not even a timestamp. If combined with the
- <option>--output-fields=</option> option will output the listed fields for each log record,
- instead of the message.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>
- <option>with-unit</option>
- </term>
- <listitem>
- <para>similar to short-full, but prefixes the unit and
- user unit names instead of the traditional syslog
- identifier. Useful when using templated instances, as it
- will include the arguments in the unit names.</para>
- </listitem>
- </varlistentry>
- </variablelist>
- </listitem>
+<refentry id="journalctl"
+ xmlns:xi="http://www.w3.org/2001/XInclude">
+
+ <refentryinfo>
+ <title>journalctl</title>
+ <productname>systemd</productname>
+ </refentryinfo>
+
+ <refmeta>
+ <refentrytitle>journalctl</refentrytitle>
+ <manvolnum>1</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+ <refname>journalctl</refname>
+ <refpurpose>Query the systemd journal</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <cmdsynopsis>
+ <command>journalctl</command>
+ <arg choice="opt" rep="repeat">OPTIONS</arg>
+ <arg choice="opt" rep="repeat">MATCHES</arg>
+ </cmdsynopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para><command>journalctl</command> may be used to query the contents of the
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> journal as
+ written by
+ <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
+
+ <para>If called without parameters, it will show the full contents of the journal, starting with the
+ oldest entry collected.</para>
+
+ <para>If one or more match arguments are passed, the output is filtered accordingly. A match is in the
+ format <literal>FIELD=VALUE</literal>, e.g. <literal>_SYSTEMD_UNIT=httpd.service</literal>, referring to
+ the components of a structured journal entry. See
+ <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+ for a list of well-known fields. If multiple matches are specified matching different fields, the log
+ entries are filtered by both, i.e. the resulting output will show only entries matching all the specified
+ matches of this kind. If two matches apply to the same field, then they are automatically matched as
+ alternatives, i.e. the resulting output will show entries matching any of the specified matches for the
+ same field. Finally, the character <literal>+</literal> may appear as a separate word between other terms
+ on the command line. This causes all matches before and after to be combined in a disjunction
+ (i.e. logical OR).</para>
+
+ <para>It is also possible to filter the entries by specifying an absolute file path as an argument. The
+ file path may be a file or a symbolic link and the file must exist at the time of the query. If a file
+ path refers to an executable binary, an <literal>_EXE=</literal> match for the canonicalized binary path
+ is added to the query. If a file path refers to an executable script, a <literal>_COMM=</literal> match
+ for the script name is added to the query. If a file path refers to a device node,
+ <literal>_KERNEL_DEVICE=</literal> matches for the kernel name of the device and for each of its ancestor
+ devices is added to the query. Symbolic links are dereferenced, kernel names are synthesized, and parent
+ devices are identified from the environment at the time of the query. In general, a device node is the
+ best proxy for an actual device, as log entries do not usually contain fields that identify an actual
+ device. For the resulting log entries to be correct for the actual device, the relevant parts of the
+ environment at the time the entry was logged, in particular the actual device corresponding to the device
+ node, must have been the same as those at the time of the query. Because device nodes generally change
+ their corresponding devices across reboots, specifying a device node path causes the resulting entries to
+ be restricted to those from the current boot.</para>
+
+ <para>Additional constraints may be added using options <option>--boot</option>,
+ <option>--unit=</option>, etc., to further limit what entries will be shown (logical AND).</para>
+
+ <para>Output is interleaved from all accessible journal files, whether they are rotated or currently
+ being written, and regardless of whether they belong to the system itself or are accessible user
+ journals. The <option>--header</option> option can be used to identify which files
+ <emphasis>are</emphasis> being shown.</para>
+
+ <para>The set of journal files which will be used can be modified using the <option>--user</option>,
+ <option>--system</option>, <option>--directory</option>, and <option>--file</option> options, see
+ below.</para>
+
+ <para>All users are granted access to their private per-user journals. However, by default, only root and
+ users who are members of a few special groups are granted access to the system journal and the journals
+ of other users. Members of the groups <literal>systemd-journal</literal>, <literal>adm</literal>, and
+ <literal>wheel</literal> can read all journal files. Note that the two latter groups traditionally have
+ additional privileges specified by the distribution. Members of the <literal>wheel</literal> group can
+ often perform administrative tasks.</para>
+
+ <para>The output is paged through <command>less</command> by default, and long lines are "truncated" to
+ screen width. The hidden part can be viewed by using the left-arrow and right-arrow keys. Paging can be
+ disabled; see the <option>--no-pager</option> option and the "Environment" section below.</para>
+
+ <para>When outputting to a tty, lines are colored according to priority: lines of level ERROR and higher
+ are colored red; lines of level NOTICE and higher are highlighted; lines of level DEBUG are colored
+ lighter grey; other lines are displayed normally.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Source Options</title>
+
+ <para>The following options control where to read journal records from:</para>
+
+ <variablelist>
+ <varlistentry>
+ <term><option>--system</option></term>
+ <term><option>--user</option></term>
+
+ <listitem><para>Show messages from system services and the kernel (with
+ <option>--system</option>). Show messages from service of current user (with
+ <option>--user</option>). If neither is specified, show all messages that the user can see.
+ </para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--output-fields=</option></term>
+ <term><option>-M</option></term>
+ <term><option>--machine=</option></term>
- <listitem><para>A comma separated list of the fields which should be included in the output. This has
- an effect only for the output modes which would normally show all fields (<option>verbose</option>,
- <option>export</option>, <option>json</option>, <option>json-pretty</option>,
- <option>json-sse</option> and <option>json-seq</option>), as well as on <option>cat</option>. For the
- former, the <literal>__CURSOR</literal>, <literal>__REALTIME_TIMESTAMP</literal>,
- <literal>__MONOTONIC_TIMESTAMP</literal>, and <literal>_BOOT_ID</literal> fields are always
- printed.</para></listitem>
+ <listitem><para>Show messages from a running, local container. Specify a container name to connect
+ to.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--utc</option></term>
+ <term><option>-m</option></term>
+ <term><option>--merge</option></term>
- <listitem><para>Express time in Coordinated Universal Time
- (UTC).</para></listitem>
+ <listitem><para>Show entries interleaved from all available journals, including remote
+ ones.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--no-hostname</option></term>
+ <term><option>-D <replaceable>DIR</replaceable></option></term>
+ <term><option>--directory=<replaceable>DIR</replaceable></option></term>
- <listitem><para>Don't show the hostname field of log messages originating from the local host. This
- switch has an effect only on the <option>short</option> family of output modes (see above).
- </para>
+ <listitem><para>Takes a directory path as argument. If specified, journalctl will operate on the
+ specified journal directory <replaceable>DIR</replaceable> instead of the default runtime and system
+ journal paths.</para></listitem>
+ </varlistentry>
- <para>Note: this option does not remove occurrences of the hostname from log entries themselves, so
- it does not prevent the hostname from being visible in the logs.</para>
- </listitem>
+ <varlistentry>
+ <term><option>--file=<replaceable>GLOB</replaceable></option></term>
+
+ <listitem><para>Takes a file glob as an argument. If specified, journalctl will operate on the
+ specified journal files matching <replaceable>GLOB</replaceable> instead of the default runtime and
+ system journal paths. May be specified multiple times, in which case files will be suitably
+ interleaved.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>-x</option></term>
- <term><option>--catalog</option></term>
+ <term><option>--root=<replaceable>ROOT</replaceable></option></term>
- <listitem><para>Augment log lines with explanation texts from
- the message catalog. This will add explanatory help texts to
- log messages in the output where this is available. These
- short help texts will explain the context of an error or log
- event, possible solutions, as well as pointers to support
- forums, developer documentation, and any other relevant
- manuals. Note that help texts are not available for all
- messages, but only for selected ones. For more information on
- the message catalog, please refer to the
- <ulink url="https://www.freedesktop.org/wiki/Software/systemd/catalog">Message Catalog Developer Documentation</ulink>.</para>
-
- <para>Note: when attaching <command>journalctl</command>
- output to bug reports, please do <emphasis>not</emphasis> use
- <option>-x</option>.</para>
- </listitem>
+ <listitem><para>Takes a directory path as an argument. If specified, <command>journalctl</command>
+ will operate on journal directories and catalog file hierarchy underneath the specified directory
+ instead of the root directory (e.g. <option>--update-catalog</option> will create
+ <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>, and journal
+ files under <filename><replaceable>ROOT</replaceable>/run/journal/</filename> or
+ <filename><replaceable>ROOT</replaceable>/var/log/journal/</filename> will be displayed).
+ </para></listitem>
</varlistentry>
<varlistentry>
- <term><option>-q</option></term>
- <term><option>--quiet</option></term>
+ <term><option>--image=<replaceable>IMAGE</replaceable></option></term>
- <listitem><para>Suppresses all informational messages
- (i.e. "-- Journal begins at …", "-- Reboot --"),
- any warning messages regarding
- inaccessible system journals when run as a normal
- user.</para></listitem>
+ <listitem><para>Takes a path to a disk image file or block device node. If specified,
+ <command>journalctl</command> will operate on the file system in the indicated disk image. This is
+ similar to <option>--root=</option> but operates on file systems stored in disk images or block
+ devices, thus providing an easy way to extract log data from disk images. The disk image should
+ either contain just a file system or a set of file systems within a GPT partition table, following
+ the <ulink url="https://systemd.io/DISCOVERABLE_PARTITIONS">Discoverable Partitions
+ Specification</ulink>. For further information on supported disk images, see
+ <citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
+ switch of the same name.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>-m</option></term>
- <term><option>--merge</option></term>
+ <term><option>--namespace=<replaceable>NAMESPACE</replaceable></option></term>
- <listitem><para>Show entries interleaved from all available
- journals, including remote ones.</para></listitem>
+ <listitem><para>Takes a journal namespace identifier string as argument. If not specified the data
+ collected by the default namespace is shown. If specified shows the log data of the specified
+ namespace instead. If the namespace is specified as <literal>*</literal> data from all namespaces is
+ shown, interleaved. If the namespace identifier is prefixed with <literal>+</literal> data from the
+ specified namespace and the default namespace is shown, interleaved, but no other. For details about
+ journal namespaces see
+ <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
</varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Filtering Options</title>
+
+ <para>The following options control how to filter journal records:</para>
+
+ <variablelist>
<varlistentry>
- <term><option>-b <optional><optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional>|<constant>all</constant></optional></option></term>
- <term><option>--boot<optional>=<optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional>|<constant>all</constant></optional></option></term>
+ <term><option>-S</option></term>
+ <term><option>--since=</option></term>
+ <term><option>-U</option></term>
+ <term><option>--until=</option></term>
- <listitem><para>Show messages from a specific boot. This will
- add a match for <literal>_BOOT_ID=</literal>.</para>
-
- <para>The argument may be empty, in which case logs for the
- current boot will be shown.</para>
-
- <para>If the boot ID is omitted, a positive
- <replaceable>offset</replaceable> will look up the boots
- starting from the beginning of the journal, and an
- equal-or-less-than zero <replaceable>offset</replaceable> will
- look up boots starting from the end of the journal. Thus,
- <constant>1</constant> means the first boot found in the
- journal in chronological order, <constant>2</constant> the
- second and so on; while <constant>-0</constant> is the last
- boot, <constant>-1</constant> the boot before last, and so
- on. An empty <replaceable>offset</replaceable> is equivalent
- to specifying <constant>-0</constant>, except when the current
- boot is not the last boot (e.g. because
- <option>--directory</option> was specified to look at logs
- from a different machine).</para>
-
- <para>If the 32-character <replaceable>ID</replaceable> is
- specified, it may optionally be followed by
- <replaceable>offset</replaceable> which identifies the boot
- relative to the one given by boot
- <replaceable>ID</replaceable>. Negative values mean earlier
- boots and positive values mean later boots. If
- <replaceable>offset</replaceable> is not specified, a value of
- zero is assumed, and the logs for the boot given by
- <replaceable>ID</replaceable> are shown.</para>
-
- <para>The special argument <constant>all</constant> can be
- used to negate the effect of an earlier use of
- <option>-b</option>.</para>
- </listitem>
+ <listitem><para>Start showing entries on or newer than the specified date, or on or older than the
+ specified date, respectively. Date specifications should be of the format <literal>2012-10-30
+ 18:17:16</literal>. If the time part is omitted, <literal>00:00:00</literal> is assumed. If only
+ the seconds component is omitted, <literal>:00</literal> is assumed. If the date component is
+ omitted, the current day is assumed. Alternatively the strings <literal>yesterday</literal>,
+ <literal>today</literal>, <literal>tomorrow</literal> are understood, which refer to 00:00:00 of the
+ day before the current day, the current day, or the day after the current day,
+ respectively. <literal>now</literal> refers to the current time. Finally, relative times may be
+ specified, prefixed with <literal>-</literal> or <literal>+</literal>, referring to times before or
+ after the current time, respectively. For complete time and date specification, see
+ <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>. Note
+ that <option>--output=short-full</option> prints timestamps that follow precisely this format.
+ </para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--list-boots</option></term>
+ <term><option>-c</option></term>
+ <term><option>--cursor=</option></term>
- <listitem><para>Show a tabular list of boot numbers (relative to
- the current boot), their IDs, and the timestamps of the first
- and last message pertaining to the boot.</para></listitem>
+ <listitem><para>Start showing entries from the location in the journal specified by the passed
+ cursor.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>-k</option></term>
- <term><option>--dmesg</option></term>
+ <term><option>--after-cursor=</option></term>
- <listitem><para>Show only kernel messages. This implies
- <option>-b</option> and adds the match
- <literal>_TRANSPORT=kernel</literal>.</para></listitem>
+ <listitem><para>Start showing entries from the location in the journal <emphasis>after</emphasis>
+ the location specified by the passed cursor. The cursor is shown when the
+ <option>--show-cursor</option> option is used.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>-t</option></term>
- <term><option>--identifier=<replaceable>SYSLOG_IDENTIFIER</replaceable></option></term>
+ <term><option>--cursor-file=<replaceable>FILE</replaceable></option></term>
- <listitem><para>Show messages for the specified syslog
- identifier
- <replaceable>SYSLOG_IDENTIFIER</replaceable>.</para>
+ <listitem><para>If <replaceable>FILE</replaceable> exists and contains a cursor, start showing
+ entries <emphasis>after</emphasis> this location. Otherwise show entries according to the other
+ given options. At the end, write the cursor of the last entry to
+ <replaceable>FILE</replaceable>. Use this option to continually read the journal by sequentially
+ calling <command>journalctl</command>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>-b <optional><optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional>|<constant>all</constant></optional></option></term>
+ <term><option>--boot<optional>=<optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional>|<constant>all</constant></optional></option></term>
+
+ <listitem><para>Show messages from a specific boot. This will add a match for
+ <literal>_BOOT_ID=</literal>.</para>
+
+ <para>The argument may be empty, in which case logs for the current boot will be shown.</para>
+
+ <para>If the boot ID is omitted, a positive <replaceable>offset</replaceable> will look up the boots
+ starting from the beginning of the journal, and an equal-or-less-than zero
+ <replaceable>offset</replaceable> will look up boots starting from the end of the journal. Thus,
+ <constant>1</constant> means the first boot found in the journal in chronological order,
+ <constant>2</constant> the second and so on; while <constant>-0</constant> is the last boot,
+ <constant>-1</constant> the boot before last, and so on. An empty <replaceable>offset</replaceable>
+ is equivalent to specifying <constant>-0</constant>, except when the current boot is not the last
+ boot (e.g. because <option>--directory</option> was specified to look at logs from a different
+ machine).</para>
+
+ <para>If the 32-character <replaceable>ID</replaceable> is specified, it may optionally be followed
+ by <replaceable>offset</replaceable> which identifies the boot relative to the one given by boot
+ <replaceable>ID</replaceable>. Negative values mean earlier boots and positive values mean later
+ boots. If <replaceable>offset</replaceable> is not specified, a value of zero is assumed, and the
+ logs for the boot given by <replaceable>ID</replaceable> are shown.</para>
- <para>This parameter can be specified multiple
- times.</para></listitem>
+ <para>The special argument <constant>all</constant> can be used to negate the effect of an earlier
+ use of <option>-b</option>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-u</option></term>
<term><option>--unit=<replaceable>UNIT</replaceable>|<replaceable>PATTERN</replaceable></option></term>
- <listitem><para>Show messages for the specified systemd unit
- <replaceable>UNIT</replaceable> (such as a service unit), or
- for any of the units matched by
- <replaceable>PATTERN</replaceable>. If a pattern is
- specified, a list of unit names found in the journal is
- compared with the specified pattern and all that match are
- used. For each unit name, a match is added for messages from
- the unit
- (<literal>_SYSTEMD_UNIT=<replaceable>UNIT</replaceable></literal>),
- along with additional matches for messages from systemd and
- messages about coredumps for the specified unit. A match
- is also added for <literal>_SYSTEMD_SLICE=<replaceable>UNIT</replaceable></literal>,
- such that if the provided <replaceable>UNIT</replaceable> is a
+ <listitem><para>Show messages for the specified systemd unit <replaceable>UNIT</replaceable> (such as
+ a service unit), or for any of the units matched by <replaceable>PATTERN</replaceable>. If a pattern
+ is specified, a list of unit names found in the journal is compared with the specified pattern and
+ all that match are used. For each unit name, a match is added for messages from the unit
+ (<literal>_SYSTEMD_UNIT=<replaceable>UNIT</replaceable></literal>), along with additional matches for
+ messages from systemd and messages about coredumps for the specified unit. A match is also added for
+ <literal>_SYSTEMD_SLICE=<replaceable>UNIT</replaceable></literal>, such that if the provided
+ <replaceable>UNIT</replaceable> is a
<citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- unit, all logs of children of the slice will be shown.
- </para>
+ unit, all logs of children of the slice will be shown.</para>
- <para>This parameter can be specified multiple times.</para>
- </listitem>
+ <para>This parameter can be specified multiple times.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--user-unit=</option></term>
- <listitem><para>Show messages for the specified user session
- unit. This will add a match for messages from the unit
- (<literal>_SYSTEMD_USER_UNIT=</literal> and
- <literal>_UID=</literal>) and additional matches for messages
- from session systemd and messages about coredumps for the
- specified unit. A match
- is also added for <literal>_SYSTEMD_USER_SLICE=<replaceable>UNIT</replaceable></literal>,
- such that if the provided <replaceable>UNIT</replaceable> is a
+ <listitem><para>Show messages for the specified user session unit. This will add a match for messages
+ from the unit (<literal>_SYSTEMD_USER_UNIT=</literal> and <literal>_UID=</literal>) and additional
+ matches for messages from session systemd and messages about coredumps for the specified unit. A
+ match is also added for <literal>_SYSTEMD_USER_SLICE=<replaceable>UNIT</replaceable></literal>, such
+ that if the provided <replaceable>UNIT</replaceable> is a
<citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>
unit, all logs of children of the unit will be shown.</para>
- <para>This parameter can be specified multiple times.</para>
- </listitem>
+ <para>This parameter can be specified multiple times.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>-t</option></term>
+ <term><option>--identifier=<replaceable>SYSLOG_IDENTIFIER</replaceable></option></term>
+
+ <listitem><para>Show messages for the specified syslog identifier
+ <replaceable>SYSLOG_IDENTIFIER</replaceable>.</para>
+
+ <para>This parameter can be specified multiple times.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-p</option></term>
<term><option>--priority=</option></term>
- <listitem><para>Filter output by message priorities or
- priority ranges. Takes either a single numeric or textual log
- level (i.e. between 0/<literal>emerg</literal> and
- 7/<literal>debug</literal>), or a range of numeric/text log
- levels in the form FROM..TO. The log levels are the usual
- syslog log levels as documented in
- <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
- i.e. <literal>emerg</literal> (0),
- <literal>alert</literal> (1), <literal>crit</literal> (2),
- <literal>err</literal> (3), <literal>warning</literal> (4),
- <literal>notice</literal> (5), <literal>info</literal> (6),
- <literal>debug</literal> (7). If a single log level is
- specified, all messages with this log level or a lower (hence
- more important) log level are shown. If a range is specified,
- all messages within the range are shown, including both the
- start and the end value of the range. This will add
- <literal>PRIORITY=</literal> matches for the specified
+ <listitem><para>Filter output by message priorities or priority ranges. Takes either a single numeric
+ or textual log level (i.e. between 0/<literal>emerg</literal> and 7/<literal>debug</literal>), or a
+ range of numeric/text log levels in the form FROM..TO. The log levels are the usual syslog log levels
+ as documented in <citerefentry
+ project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ i.e. <literal>emerg</literal> (0), <literal>alert</literal> (1), <literal>crit</literal> (2),
+ <literal>err</literal> (3), <literal>warning</literal> (4), <literal>notice</literal> (5),
+ <literal>info</literal> (6), <literal>debug</literal> (7). If a single log level is specified, all
+ messages with this log level or a lower (hence more important) log level are shown. If a range is
+ specified, all messages within the range are shown, including both the start and the end value of the
+ range. This will add <literal>PRIORITY=</literal> matches for the specified
priorities.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--facility=</option></term>
- <listitem><para>Filter output by syslog facility. Takes a comma-separated list of numbers or facility
- names. The names are the usual syslog facilities as documented in
- <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
+ <listitem><para>Filter output by syslog facility. Takes a comma-separated list of numbers or
+ facility names. The names are the usual syslog facilities as documented in <citerefentry
+ project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
<option>--facility=help</option> may be used to display a list of known facility names and exit.
</para></listitem>
</varlistentry>
<term><option>-g</option></term>
<term><option>--grep=</option></term>
- <listitem><para>Filter output to entries where the <varname>MESSAGE=</varname>
- field matches the specified regular expression. PERL-compatible regular expressions
- are used, see
- <citerefentry project='url'><refentrytitle url='http://pcre.org/current/doc/html/pcre2pattern.html'>pcre2pattern</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ <listitem><para>Filter output to entries where the <varname>MESSAGE=</varname> field matches the
+ specified regular expression. PERL-compatible regular expressions are used, see <citerefentry
+ project='url'><refentrytitle
+ url='http://pcre.org/current/doc/html/pcre2pattern.html'>pcre2pattern</refentrytitle><manvolnum>3</manvolnum></citerefentry>
for a detailed description of the syntax.</para>
- <para>If the pattern is all lowercase, matching is case insensitive.
- Otherwise, matching is case sensitive. This can be overridden with the
- <option>--case-sensitive</option> option, see below.</para>
- </listitem>
+ <para>If the pattern is all lowercase, matching is case insensitive. Otherwise, matching is case
+ sensitive. This can be overridden with the <option>--case-sensitive</option> option, see
+ below.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--case-sensitive<optional>=BOOLEAN</optional></option></term>
- <listitem><para>Make pattern matching case sensitive or case insensitive.</para>
- </listitem>
+ <listitem><para>Make pattern matching case sensitive or case insensitive.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>-c</option></term>
- <term><option>--cursor=</option></term>
+ <term><option>-k</option></term>
+ <term><option>--dmesg</option></term>
- <listitem><para>Start showing entries from the location in the
- journal specified by the passed cursor.</para></listitem>
+ <listitem><para>Show only kernel messages. This implies <option>-b</option> and adds the match
+ <literal>_TRANSPORT=kernel</literal>.</para></listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Output Options</title>
+
+ <para>The following options control how journal records are printed:</para>
+
+ <variablelist>
+ <varlistentry>
+ <term><option>-o</option></term>
+ <term><option>--output=</option></term>
+
+ <listitem><para>Controls the formatting of the journal entries that are shown. Takes one of the
+ following options:</para>
+
+ <variablelist>
+ <varlistentry>
+ <term><option>short</option></term>
+ <listitem><para>is the default and generates an output that is mostly identical to the
+ formatting of classic syslog files, showing one line per journal entry.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>short-full</option></term>
+ <listitem><para>is very similar, but shows timestamps in the format the
+ <option>--since=</option> and <option>--until=</option> options accept. Unlike the timestamp
+ information shown in <option>short</option> output mode this mode includes weekday, year and
+ timezone information in the output, and is locale-independent.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>short-iso</option></term>
+ <listitem><para>is very similar, but shows ISO 8601 wallclock timestamps.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>short-iso-precise</option></term>
+ <listitem><para>as for <option>short-iso</option> but includes full microsecond
+ precision.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>short-precise</option></term>
+ <listitem><para>is very similar, but shows classic syslog timestamps with full microsecond
+ precision.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>short-monotonic</option></term>
+ <listitem><para>is very similar, but shows monotonic timestamps instead of wallclock
+ timestamps.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>short-unix</option></term>
+ <listitem><para>is very similar, but shows seconds passed since January 1st 1970 UTC instead of
+ wallclock timestamps ("UNIX time"). The time is shown with microsecond accuracy.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>verbose</option></term>
+ <listitem><para>shows the full-structured entry items with all fields.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>export</option></term>
+ <listitem><para>serializes the journal into a binary (but mostly text-based) stream suitable
+ for backups and network transfer (see <ulink
+ url="https://systemd.io/JOURNAL_EXPORT_FORMATS#journal-export-format">Journal Export
+ Format</ulink> for more information). To import the binary stream back into native journald
+ format use
+ <citerefentry><refentrytitle>systemd-journal-remote</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>json</option></term>
+ <listitem><para>formats entries as JSON objects, separated by newline characters (see <ulink
+ url="https://systemd.io/JOURNAL_EXPORT_FORMATS#journal-json-format">Journal JSON Format</ulink>
+ for more information). Field values are generally encoded as JSON strings, with three exceptions:
+ <orderedlist>
+ <listitem><para>Fields larger than 4096 bytes are encoded as <constant>null</constant>
+ values. (This may be turned off by passing <option>--all</option>, but be aware that this may
+ allocate overly long JSON objects.)</para></listitem>
+
+ <listitem><para>Journal entries permit non-unique fields within the same log entry. JSON does
+ not allow non-unique fields within objects. Due to this, if a non-unique field is encountered a
+ JSON array is used as field value, listing all field values as elements.</para></listitem>
+
+ <listitem><para>Fields containing non-printable or non-UTF8 bytes are encoded as arrays
+ containing the raw bytes individually formatted as unsigned numbers.</para></listitem>
+ </orderedlist>
+
+ Note that this encoding is reversible (with the exception of the size limit).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>json-pretty</option></term>
+ <listitem><para>formats entries as JSON data structures, but formats them in multiple lines in
+ order to make them more readable by humans.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>json-sse</option></term>
+ <listitem><para>formats entries as JSON data structures, but wraps them in a format suitable for
+ <ulink
+ url="https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">Server-Sent
+ Events</ulink>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>json-seq</option></term>
+ <listitem><para>formats entries as JSON data structures, but prefixes them with an ASCII Record
+ Separator character (0x1E) and suffixes them with an ASCII Line Feed character (0x0A), in
+ accordance with <ulink url="https://tools.ietf.org/html/rfc7464">JavaScript Object Notation
+ (JSON) Text Sequences </ulink> (<literal>application/json-seq</literal>).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>cat</option></term>
+ <listitem><para>generates a very terse output, only showing the actual message of each journal
+ entry with no metadata, not even a timestamp. If combined with the
+ <option>--output-fields=</option> option will output the listed fields for each log record,
+ instead of the message.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>with-unit</option></term>
+ <listitem><para>similar to short-full, but prefixes the unit and user unit names instead of the
+ traditional syslog identifier. Useful when using templated instances, as it will include the
+ arguments in the unit names.</para></listitem>
+ </varlistentry>
+ </variablelist></listitem>
</varlistentry>
<varlistentry>
- <term><option>--cursor-file=<replaceable>FILE</replaceable></option></term>
+ <term><option>--output-fields=</option></term>
- <listitem><para>If <replaceable>FILE</replaceable> exists and contains a
- cursor, start showing entries <emphasis>after</emphasis> this location.
- Otherwise show entries according to the other given options. At the end,
- write the cursor of the last entry to <replaceable>FILE</replaceable>. Use
- this option to continually read the journal by sequentially calling
- <command>journalctl</command>.</para></listitem>
+ <listitem><para>A comma separated list of the fields which should be included in the output. This
+ has an effect only for the output modes which would normally show all fields
+ (<option>verbose</option>, <option>export</option>, <option>json</option>,
+ <option>json-pretty</option>, <option>json-sse</option> and <option>json-seq</option>), as well as
+ on <option>cat</option>. For the former, the <literal>__CURSOR</literal>,
+ <literal>__REALTIME_TIMESTAMP</literal>, <literal>__MONOTONIC_TIMESTAMP</literal>, and
+ <literal>_BOOT_ID</literal> fields are always printed.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--after-cursor=</option></term>
+ <term><option>-n</option></term>
+ <term><option>--lines=</option></term>
- <listitem><para>Start showing entries from the location in the
- journal <emphasis>after</emphasis> the location specified by
- the passed cursor. The cursor is shown when the
- <option>--show-cursor</option> option is used.</para>
- </listitem>
+ <listitem><para>Show the most recent journal events and limit the number of events shown. If
+ <option>--follow</option> is used, this option is implied. The argument is a positive integer or
+ <literal>all</literal> to disable line limiting. The default value is 10 if no argument is
+ given.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--show-cursor</option></term>
+ <term><option>-r</option></term>
+ <term><option>--reverse</option></term>
- <listitem><para>The cursor is shown after the last entry after
- two dashes:</para>
- <programlisting>-- cursor: s=0639…</programlisting>
- <para>The format of the cursor is private
- and subject to change.</para></listitem>
+ <listitem><para>Reverse output so that the newest entries are displayed first.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>-S</option></term>
- <term><option>--since=</option></term>
- <term><option>-U</option></term>
- <term><option>--until=</option></term>
+ <term><option>--show-cursor</option></term>
- <listitem><para>Start showing entries on or newer than the specified date, or on or older than the specified
- date, respectively. Date specifications should be of the format <literal>2012-10-30 18:17:16</literal>. If the
- time part is omitted, <literal>00:00:00</literal> is assumed. If only the seconds component is omitted,
- <literal>:00</literal> is assumed. If the date component is omitted, the current day is assumed. Alternatively
- the strings <literal>yesterday</literal>, <literal>today</literal>, <literal>tomorrow</literal> are understood,
- which refer to 00:00:00 of the day before the current day, the current day, or the day after the current day,
- respectively. <literal>now</literal> refers to the current time. Finally, relative times may be specified,
- prefixed with <literal>-</literal> or <literal>+</literal>, referring to times before or after the current
- time, respectively. For complete time and date specification, see
- <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>. Note that
- <option>--output=short-full</option> prints timestamps that follow precisely this format.
- </para>
- </listitem>
+ <listitem><para>The cursor is shown after the last entry after two dashes:</para>
+ <programlisting>-- cursor: s=0639…</programlisting>
+ <para>The format of the cursor is private and subject to change.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>-F</option></term>
- <term><option>--field=</option></term>
+ <term><option>--utc</option></term>
- <listitem><para>Print all possible data values the specified
- field can take in all entries of the journal.</para></listitem>
+ <listitem><para>Express time in Coordinated Universal Time (UTC).</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>-N</option></term>
- <term><option>--fields</option></term>
+ <term><option>-x</option></term>
+ <term><option>--catalog</option></term>
- <listitem><para>Print all field names currently used in all entries of the journal.</para></listitem>
+ <listitem><para>Augment log lines with explanation texts from the message catalog. This will add
+ explanatory help texts to log messages in the output where this is available. These short help texts
+ will explain the context of an error or log event, possible solutions, as well as pointers to support
+ forums, developer documentation, and any other relevant manuals. Note that help texts are not
+ available for all messages, but only for selected ones. For more information on the message catalog,
+ please refer to the <ulink url="https://www.freedesktop.org/wiki/Software/systemd/catalog">Message
+ Catalog Developer Documentation</ulink>.</para>
+
+ <para>Note: when attaching <command>journalctl</command> output to bug reports, please do
+ <emphasis>not</emphasis> use <option>-x</option>.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--system</option></term>
- <term><option>--user</option></term>
+ <term><option>--no-hostname</option></term>
- <listitem><para>Show messages from system services and the
- kernel (with <option>--system</option>). Show messages from
- service of current user (with <option>--user</option>). If
- neither is specified, show all messages that the user can see.
- </para></listitem>
+ <listitem><para>Don't show the hostname field of log messages originating from the local host. This
+ switch has an effect only on the <option>short</option> family of output modes (see above).</para>
+
+ <para>Note: this option does not remove occurrences of the hostname from log entries themselves, so
+ it does not prevent the hostname from being visible in the logs.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>-M</option></term>
- <term><option>--machine=</option></term>
+ <term><option>--no-full</option></term>
+ <term><option>--full</option></term>
+ <term><option>-l</option></term>
+
+ <listitem><para>Ellipsize fields when they do not fit in available columns. The default is to show
+ full fields, allowing them to wrap or be truncated by the pager, if one is used.</para>
- <listitem><para>Show messages from a running, local
- container. Specify a container name to connect to.</para>
- </listitem>
+ <para>The old options <option>-l</option>/<option>--full</option> are not useful anymore, except to
+ undo <option>--no-full</option>.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>-D <replaceable>DIR</replaceable></option></term>
- <term><option>--directory=<replaceable>DIR</replaceable></option></term>
+ <term><option>-a</option></term>
+ <term><option>--all</option></term>
- <listitem><para>Takes a directory path as argument. If
- specified, journalctl will operate on the specified journal
- directory <replaceable>DIR</replaceable> instead of the
- default runtime and system journal paths.</para></listitem>
+ <listitem><para>Show all fields in full, even if they include unprintable characters or are very
+ long. By default, fields with unprintable characters are abbreviated as "blob data". (Note that the
+ pager may escape unprintable characters again.)</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--file=<replaceable>GLOB</replaceable></option></term>
+ <term><option>-f</option></term>
+ <term><option>--follow</option></term>
- <listitem><para>Takes a file glob as an argument. If
- specified, journalctl will operate on the specified journal
- files matching <replaceable>GLOB</replaceable> instead of the
- default runtime and system journal paths. May be specified
- multiple times, in which case files will be suitably
- interleaved.</para></listitem>
+ <listitem><para>Show only the most recent journal entries, and continuously print new entries as
+ they are appended to the journal.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--root=<replaceable>ROOT</replaceable></option></term>
+ <term><option>--no-tail</option></term>
- <listitem><para>Takes a directory path as an argument. If specified, <command>journalctl</command>
- will operate on journal directories and catalog file hierarchy underneath the specified directory
- instead of the root directory (e.g. <option>--update-catalog</option> will create
- <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>, and journal
- files under <filename><replaceable>ROOT</replaceable>/run/journal/</filename> or
- <filename><replaceable>ROOT</replaceable>/var/log/journal/</filename> will be displayed).
- </para></listitem>
+ <listitem><para>Show all stored output lines, even in follow mode. Undoes the effect of
+ <option>--lines=</option>.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--image=<replaceable>IMAGE</replaceable></option></term>
+ <term><option>-q</option></term>
+ <term><option>--quiet</option></term>
- <listitem><para>Takes a path to a disk image file or block device node. If specified,
- <command>journalctl</command> will operate on the file system in the indicated disk image. This is
- similar to <option>--root=</option> but operates on file systems stored in disk images or block
- devices, thus providing an easy way to extract log data from disk images. The disk image should
- either contain just a file system or a set of file systems within a GPT partition table, following
- the <ulink url="https://systemd.io/DISCOVERABLE_PARTITIONS">Discoverable Partitions
- Specification</ulink>. For further information on supported disk images, see
- <citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
- switch of the same name.</para></listitem>
+ <listitem><para>Suppresses all informational messages (i.e. "-- Journal begins at …", "-- Reboot
+ --"), any warning messages regarding inaccessible system journals when run as a normal
+ user.</para></listitem>
</varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Pager Control Options</title>
+
+ <para>The following options control page support:</para>
+
+ <variablelist>
+
+ <xi:include href="standard-options.xml" xpointer="no-pager" />
<varlistentry>
- <term><option>--namespace=<replaceable>NAMESPACE</replaceable></option></term>
+ <term><option>-e</option></term>
+ <term><option>--pager-end</option></term>
- <listitem><para>Takes a journal namespace identifier string as argument. If not specified the data
- collected by the default namespace is shown. If specified shows the log data of the specified
- namespace instead. If the namespace is specified as <literal>*</literal> data from all namespaces is
- shown, interleaved. If the namespace identifier is prefixed with <literal>+</literal> data from the
- specified namespace and the default namespace is shown, interleaved, but no other. For details about
- journal namespaces see
- <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
+ <listitem><para>Immediately jump to the end of the journal inside the implied pager tool. This
+ implies <option>-n1000</option> to guarantee that the pager will not buffer logs of unbounded
+ size. This may be overridden with an explicit <option>-n</option> with some other numeric value,
+ while <option>-nall</option> will disable this cap. Note that this option is only supported for
+ the <citerefentry
+ project='man-pages'><refentrytitle>less</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ pager.</para></listitem>
</varlistentry>
+ </variablelist>
+ </refsect1>
- <varlistentry>
- <term><option>--header</option></term>
+ <refsect1>
+ <title>Forward Secure Sealing (FSS) Options</title>
- <listitem><para>Instead of showing journal contents, show internal header information of the journal
- fields accessed.</para>
+ <para>The following options make be used together with the <option>--setup-keys</option> command, see below.</para>
- <para>This option is particularly useful when trying to identify out-of-order journal entries, as
- happens for example when the machine is booted with the wrong system time.</para></listitem>
+ <variablelist>
+ <varlistentry>
+ <term><option>--interval=</option></term>
+
+ <listitem><para>Specifies the change interval for the sealing key when generating an FSS key pair
+ with <option>--setup-keys</option>. Shorter intervals increase CPU consumption but shorten the time
+ range of undetectable journal alterations. Defaults to 15min.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--disk-usage</option></term>
+ <term><option>--verify-key=</option></term>
- <listitem><para>Shows the current disk usage of all journal
- files. This shows the sum of the disk usage of all archived
- and active journal files.</para></listitem>
+ <listitem><para>Specifies the FSS verification key to use for the <option>--verify</option>
+ operation.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--vacuum-size=</option></term>
- <term><option>--vacuum-time=</option></term>
- <term><option>--vacuum-files=</option></term>
+ <term><option>--force</option></term>
- <listitem><para>Removes the oldest archived journal files until the disk space they use falls below the
- specified size (specified with the usual <literal>K</literal>, <literal>M</literal>, <literal>G</literal> and
- <literal>T</literal> suffixes), or all archived journal files contain no data older than the specified timespan
- (specified with the usual <literal>s</literal>, <literal>m</literal>, <literal>h</literal>,
- <literal>days</literal>, <literal>months</literal>, <literal>weeks</literal> and <literal>years</literal>
- suffixes), or no more than the specified number of separate journal files remain. Note that running
- <option>--vacuum-size=</option> has only an indirect effect on the output shown by
- <option>--disk-usage</option>, as the latter includes active journal files, while the vacuuming operation only
- operates on archived journal files. Similarly, <option>--vacuum-files=</option> might not actually reduce the
- number of journal files to below the specified number, as it will not remove active journal
- files.</para>
-
- <para><option>--vacuum-size=</option>, <option>--vacuum-time=</option> and <option>--vacuum-files=</option>
- may be combined in a single invocation to enforce any combination of a size, a time and a number of files limit
- on the archived journal files. Specifying any of these three parameters as zero is equivalent to not enforcing
- the specific limit, and is thus redundant.</para>
-
- <para>These three switches may also be combined with <option>--rotate</option> into one command. If so, all
- active files are rotated first, and the requested vacuuming operation is executed right after. The rotation has
- the effect that all currently active files are archived (and potentially new, empty journal files opened as
- replacement), and hence the vacuuming operation has the greatest effect as it can take all log data written so
- far into account.</para></listitem>
+ <listitem><para>When <option>--setup-keys</option> is passed and Forward Secure Sealing (FSS) has
+ already been configured, recreate FSS keys.</para></listitem>
</varlistentry>
+ </variablelist>
+ </refsect1>
- <varlistentry>
- <term><option>--list-catalog
- <optional><replaceable>128-bit-ID…</replaceable></optional>
- </option></term>
+ <refsect1>
+ <title>Commands</title>
+
+ <para>The following commands are understood. If none is specified the default is to display journal records.</para>
- <listitem><para>List the contents of the message catalog as a
- table of message IDs, plus their short description strings.
- </para>
+ <variablelist>
+ <varlistentry>
+ <term><option>-N</option></term>
+ <term><option>--fields</option></term>
- <para>If any <replaceable>128-bit-ID</replaceable>s are
- specified, only those entries are shown.</para>
- </listitem>
+ <listitem><para>Print all field names currently used in all entries of the journal.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--dump-catalog
- <optional><replaceable>128-bit-ID…</replaceable></optional>
- </option></term>
-
- <listitem><para>Show the contents of the message catalog, with
- entries separated by a line consisting of two dashes and the
- ID (the format is the same as <filename>.catalog</filename>
- files).</para>
+ <term><option>-F</option></term>
+ <term><option>--field=</option></term>
- <para>If any <replaceable>128-bit-ID</replaceable>s are
- specified, only those entries are shown.</para>
- </listitem>
+ <listitem><para>Print all possible data values the specified field can take in all entries of the
+ journal.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--update-catalog</option></term>
+ <term><option>--list-boots</option></term>
- <listitem><para>Update the message catalog index. This command
- needs to be executed each time new catalog files are
- installed, removed, or updated to rebuild the binary catalog
- index.</para></listitem>
+ <listitem><para>Show a tabular list of boot numbers (relative to the current boot), their IDs, and
+ the timestamps of the first and last message pertaining to the boot.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--setup-keys</option></term>
+ <term><option>--disk-usage</option></term>
- <listitem><para>Instead of showing journal contents, generate
- a new key pair for Forward Secure Sealing (FSS). This will
- generate a sealing key and a verification key. The sealing key
- is stored in the journal data directory and shall remain on
- the host. The verification key should be stored
- externally. Refer to the <option>Seal=</option> option in
- <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- for information on Forward Secure Sealing and for a link to a
- refereed scholarly paper detailing the cryptographic theory it
- is based on.</para></listitem>
+ <listitem><para>Shows the current disk usage of all journal files. This shows the sum of the disk
+ usage of all archived and active journal files.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--force</option></term>
+ <term><option>--vacuum-size=</option></term>
+ <term><option>--vacuum-time=</option></term>
+ <term><option>--vacuum-files=</option></term>
+
+ <listitem><para>Removes the oldest archived journal files until the disk space they use falls below
+ the specified size (specified with the usual <literal>K</literal>, <literal>M</literal>,
+ <literal>G</literal> and <literal>T</literal> suffixes), or all archived journal files contain no
+ data older than the specified timespan (specified with the usual <literal>s</literal>,
+ <literal>m</literal>, <literal>h</literal>, <literal>days</literal>, <literal>months</literal>,
+ <literal>weeks</literal> and <literal>years</literal> suffixes), or no more than the specified
+ number of separate journal files remain. Note that running <option>--vacuum-size=</option> has only
+ an indirect effect on the output shown by <option>--disk-usage</option>, as the latter includes
+ active journal files, while the vacuuming operation only operates on archived journal
+ files. Similarly, <option>--vacuum-files=</option> might not actually reduce the number of journal
+ files to below the specified number, as it will not remove active journal files.</para>
- <listitem><para>When <option>--setup-keys</option> is passed
- and Forward Secure Sealing (FSS) has already been configured,
- recreate FSS keys.</para></listitem>
+ <para><option>--vacuum-size=</option>, <option>--vacuum-time=</option> and
+ <option>--vacuum-files=</option> may be combined in a single invocation to enforce any combination
+ of a size, a time and a number of files limit on the archived journal files. Specifying any of
+ these three parameters as zero is equivalent to not enforcing the specific limit, and is thus
+ redundant.</para>
+
+ <para>These three switches may also be combined with <option>--rotate</option> into one command. If
+ so, all active files are rotated first, and the requested vacuuming operation is executed right
+ after. The rotation has the effect that all currently active files are archived (and potentially new,
+ empty journal files opened as replacement), and hence the vacuuming operation has the greatest effect
+ as it can take all log data written so far into account.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--interval=</option></term>
+ <term><option>--verify</option></term>
- <listitem><para>Specifies the change interval for the sealing
- key when generating an FSS key pair with
- <option>--setup-keys</option>. Shorter intervals increase CPU
- consumption but shorten the time range of undetectable journal
- alterations. Defaults to 15min.</para></listitem>
+ <listitem><para>Check the journal file for internal consistency. If the file has been generated
+ with FSS enabled and the FSS verification key has been specified with
+ <option>--verify-key=</option>, authenticity of the journal file is verified.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--verify</option></term>
+ <term><option>--sync</option></term>
- <listitem><para>Check the journal file for internal
- consistency. If the file has been generated with FSS enabled and
- the FSS verification key has been specified with
- <option>--verify-key=</option>, authenticity of the journal file
- is verified.</para></listitem>
+ <listitem><para>Asks the journal daemon to write all yet unwritten journal data to the backing file
+ system and synchronize all journals. This call does not return until the synchronization operation
+ is complete. This command guarantees that any log messages written before its invocation are safely
+ stored on disk at the time it returns.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--verify-key=</option></term>
+ <term><option>--relinquish-var</option></term>
- <listitem><para>Specifies the FSS verification key to use for
- the <option>--verify</option> operation.</para></listitem>
+ <listitem><para>Asks the journal daemon for the reverse operation to <option>--flush</option>: if
+ requested the daemon will write further log data to <filename>/run/log/journal/</filename> and
+ stops writing to <filename>/var/log/journal/</filename>. A subsequent call to
+ <option>--flush</option> causes the log output to switch back to
+ <filename>/var/log/journal/</filename>, see above.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--sync</option></term>
+ <term><option>--smart-relinquish-var</option></term>
- <listitem><para>Asks the journal daemon to write all yet
- unwritten journal data to the backing file system and
- synchronize all journals. This call does not return until the
- synchronization operation is complete. This command guarantees
- that any log messages written before its invocation are safely
- stored on disk at the time it returns.</para></listitem>
+ <listitem><para>Similar to <option>--relinquish-var</option> but executes no operation if the root
+ file system and <filename>/var/lib/journal/</filename> reside on the same mount point. This
+ operation is used during system shutdown in order to make the journal daemon stop writing data to
+ <filename>/var/log/journal/</filename> in case that directory is located on a mount point that
+ needs to be unmounted.</para></listitem>
</varlistentry>
<varlistentry>
</varlistentry>
<varlistentry>
- <term><option>--relinquish-var</option></term>
+ <term><option>--rotate</option></term>
- <listitem><para>Asks the journal daemon for the reverse operation to <option>--flush</option>: if
- requested the daemon will write further log data to <filename>/run/log/journal/</filename> and stops
- writing to <filename>/var/log/journal/</filename>. A subsequent call to <option>--flush</option>
- causes the log output to switch back to <filename>/var/log/journal/</filename>, see
- above.</para></listitem>
+ <listitem><para>Asks the journal daemon to rotate journal files. This call does not return until
+ the rotation operation is complete. Journal file rotation has the effect that all currently active
+ journal files are marked as archived and renamed, so that they are never written to in future. New
+ (empty) journal files are then created in their place. This operation may be combined with
+ <option>--vacuum-size=</option>, <option>--vacuum-time=</option> and
+ <option>--vacuum-file=</option> into a single command, see above.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--smart-relinquish-var</option></term>
+ <term><option>--header</option></term>
- <listitem><para>Similar to <option>--relinquish-var</option> but executes no operation if the root file
- system and <filename>/var/lib/journal/</filename> reside on the same mount point. This operation is
- used during system shutdown in order to make the journal daemon stop writing data to
- <filename>/var/log/journal/</filename> in case that directory is located on a mount point that needs
- to be unmounted.</para></listitem>
+ <listitem><para>Instead of showing journal contents, show internal header information of the
+ journal fields accessed.</para>
+
+ <para>This option is particularly useful when trying to identify out-of-order journal entries, as
+ happens for example when the machine is booted with the wrong system time.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--rotate</option></term>
+ <term><option>--list-catalog <optional><replaceable>128-bit-ID…</replaceable></optional></option></term>
- <listitem><para>Asks the journal daemon to rotate journal files. This call does not return until the rotation
- operation is complete. Journal file rotation has the effect that all currently active journal files are marked
- as archived and renamed, so that they are never written to in future. New (empty) journal files are then
- created in their place. This operation may be combined with <option>--vacuum-size=</option>,
- <option>--vacuum-time=</option> and <option>--vacuum-file=</option> into a single command, see
- above.</para></listitem>
+ <listitem><para>List the contents of the message catalog as a table of message IDs, plus their
+ short description strings.</para>
+
+ <para>If any <replaceable>128-bit-ID</replaceable>s are specified, only those entries are
+ shown.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--dump-catalog <optional><replaceable>128-bit-ID…</replaceable></optional></option></term>
+
+ <listitem><para>Show the contents of the message catalog, with entries separated by a line
+ consisting of two dashes and the ID (the format is the same as <filename>.catalog</filename>
+ files).</para>
+
+ <para>If any <replaceable>128-bit-ID</replaceable>s are specified, only those entries are
+ shown.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--update-catalog</option></term>
+
+ <listitem><para>Update the message catalog index. This command needs to be executed each time new
+ catalog files are installed, removed, or updated to rebuild the binary catalog
+ index.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--setup-keys</option></term>
+
+ <listitem><para>Instead of showing journal contents, generate a new key pair for Forward Secure
+ Sealing (FSS). This will generate a sealing key and a verification key. The sealing key is stored in
+ the journal data directory and shall remain on the host. The verification key should be stored
+ externally. Refer to the <option>Seal=</option> option in
+ <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
+ information on Forward Secure Sealing and for a link to a refereed scholarly paper detailing the
+ cryptographic theory it is based on.</para></listitem>
</varlistentry>
<xi:include href="standard-options.xml" xpointer="help" />
<xi:include href="standard-options.xml" xpointer="version" />
- <xi:include href="standard-options.xml" xpointer="no-pager" />
</variablelist>
</refsect1>
<refsect1>
<title>Exit status</title>
- <para>On success, 0 is returned; otherwise, a non-zero failure
- code is returned.</para>
+ <para>On success, 0 is returned; otherwise, a non-zero failure code is returned.</para>
</refsect1>
<xi:include href="common-variables.xml" />
<refsect1>
<title>Examples</title>
- <para>Without arguments, all collected logs are shown
- unfiltered:</para>
+ <para>Without arguments, all collected logs are shown unfiltered:</para>
<programlisting>journalctl</programlisting>
- <para>With one match specified, all entries with a field matching
- the expression are shown:</para>
+ <para>With one match specified, all entries with a field matching the expression are shown:</para>
<programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service
journalctl _SYSTEMD_CGROUP=/user.slice/user-42.slice/session-c1.scope</programlisting>
- <para>If two different fields are matched, only entries matching
- both expressions at the same time are shown:</para>
+ <para>If two different fields are matched, only entries matching both expressions at the same time are
+ shown:</para>
<programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
- <para>If two matches refer to the same field, all entries matching
- either expression are shown:</para>
+ <para>If two matches refer to the same field, all entries matching either expression are shown:</para>
<programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
- <para>If the separator <literal>+</literal> is used, two
- expressions may be combined in a logical OR. The following will
- show all messages from the Avahi service process with the PID
- 28097 plus all messages from the D-Bus service (from any of its
- processes):</para>
+ <para>If the separator <literal>+</literal> is used, two expressions may be combined in a logical OR. The
+ following will show all messages from the Avahi service process with the PID 28097 plus all messages from
+ the D-Bus service (from any of its processes):</para>
<programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
- <para>To show all fields emitted <emphasis>by</emphasis> a unit and <emphasis>about</emphasis>
- the unit, option <option>-u</option>/<option>--unit=</option> should be used.
- <command>journalctl -u <replaceable>name</replaceable></command>
- expands to a complex filter similar to
+ <para>To show all fields emitted <emphasis>by</emphasis> a unit and <emphasis>about</emphasis> the unit,
+ option <option>-u</option>/<option>--unit=</option> should be used. <command>journalctl -u
+ <replaceable>name</replaceable></command> expands to a complex filter similar to
+
<programlisting>_SYSTEMD_UNIT=<replaceable>name</replaceable>.service
+ UNIT=<replaceable>name</replaceable>.service _PID=1
+ OBJECT_SYSTEMD_UNIT=<replaceable>name</replaceable>.service _UID=0
- + COREDUMP_UNIT=<replaceable>name</replaceable>.service _UID=0 MESSAGE_ID=fc2e22bc6ee647b6b90729ab34a250b1
- </programlisting>
- (see <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
- for an explanation of those patterns).
- </para>
+ + COREDUMP_UNIT=<replaceable>name</replaceable>.service _UID=0 MESSAGE_ID=fc2e22bc6ee647b6b90729ab34a250b1</programlisting>
+
+ (see
+ <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+ for an explanation of those patterns).</para>
<para>Show all logs generated by the D-Bus executable:</para>
<programlisting>journalctl -k -b -1</programlisting>
- <para>Show a live log display from a system service
- <filename>apache.service</filename>:</para>
+ <para>Show a live log display from a system service <filename>apache.service</filename>:</para>
<programlisting>journalctl -f -u apache</programlisting>
-
</refsect1>
<refsect1>
projects / thirdparty / systemd.git / commitdiff
