| <?xml version='1.0'?> <!--*-nxml-*--> |
| <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" |
| "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>Print log entries from 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> is used to print the log entries stored in the journal by |
| <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> |
| and |
| <citerefentry><refentrytitle>systemd-journal-remote.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>. |
| </para> |
| |
| <para>If called without parameters, it will show the contents of the journal accessible to the calling |
| user, 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> |
| |
| <para>To write entries <emphasis>to</emphasis> the journal, a few methods may be used. In general, output |
| from systemd units is automatically connected to the journal, see |
| <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>. |
| In addition, |
| <citerefentry><refentrytitle>systemd-cat</refentrytitle><manvolnum>1</manvolnum></citerefentry> |
| may be used to send messages to the journal directly.</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> |
| |
| <para>The <option>--user</option> option affects how <option>--unit</option> arguments are |
| treated. See <option>--unit</option>.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>-M</option></term> |
| <term><option>--machine=</option></term> |
| |
| <listitem><para>Show messages from a running, local container. Specify a container name to connect |
| to.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>-m</option></term> |
| <term><option>--merge</option></term> |
| |
| <listitem><para>Show entries interleaved from all available journals, including remote |
| ones.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>-D <replaceable>DIR</replaceable></option></term> |
| <term><option>--directory=<replaceable>DIR</replaceable></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> |
| </varlistentry> |
| |
| <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>--root=<replaceable>ROOT</replaceable></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> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>--image=<replaceable>IMAGE</replaceable></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 |
| option 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://uapi-group.org/specifications/specs/discoverable_partitions_specification">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>--namespace=<replaceable>NAMESPACE</replaceable></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> |
| </varlistentry> |
| </variablelist> |
| </refsect1> |
| |
| <refsect1> |
| <title>Filtering Options</title> |
| |
| <para>The following options control how to filter journal records:</para> |
| |
| <variablelist> |
| <varlistentry> |
| <term><option>-S</option></term> |
| <term><option>--since=</option></term> |
| <term><option>-U</option></term> |
| <term><option>--until=</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> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>-c</option></term> |
| <term><option>--cursor=</option></term> |
| |
| <listitem><para>Start showing entries from the location in the journal specified by the passed |
| cursor.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>--after-cursor=</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> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>--cursor-file=<replaceable>FILE</replaceable></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> |
| </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>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 |
| <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry> |
| unit, all logs of children of the slice will be shown.</para> |
| |
| <para>With <option>--user</option>, all <option>--unit</option> arguments will be converted to match |
| user messages as if specified with <option>--user-unit</option>.</para> |
| |
| <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 |
| <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> |
| </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 |
| 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>. |
| <option>--facility=help</option> may be used to display a list of known facility names and exit. |
| </para></listitem> |
| </varlistentry> |
| |
| <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> |
| 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> |
| |
| <para>When used with <option>--lines=</option>, <option>--reverse</option> is implied.</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> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>-k</option></term> |
| <term><option>--dmesg</option></term> |
| |
| <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-delta</option></term> |
| <listitem><para>as for <option>short-monotonic</option> but includes the time difference |
| to the previous entry. |
| Maybe unreliable time differences are marked by a <literal>*</literal>.</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 <option>short-full</option>, 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>--output-fields=</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> |
| </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> |
| |
| <para>When used with <option>--grep=</option>, <option>--reverse</option> is implied.</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>--show-cursor</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> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>--utc</option></term> |
| |
| <listitem><para>Express time in Coordinated Universal Time (UTC).</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>-x</option></term> |
| <term><option>--catalog</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> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>--no-hostname</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> |
| |
| <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>--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>--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>-q</option></term> |
| <term><option>--quiet</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> |
| </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>-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> |
| </variablelist> |
| </refsect1> |
| |
| <refsect1> |
| <title>Forward Secure Sealing (FSS) Options</title> |
| |
| <para>The following options may be used together with the <option>--setup-keys</option> command described |
| below:</para> |
| |
| <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>--verify-key=</option></term> |
| |
| <listitem><para>Specifies the FSS verification key to use for the <option>--verify</option> |
| operation.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>--force</option></term> |
| |
| <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> |
| |
| <refsect1> |
| <title>Commands</title> |
| |
| <para>The following commands are understood. If none is specified the default is to display journal records.</para> |
| |
| <variablelist> |
| <varlistentry> |
| <term><option>-N</option></term> |
| <term><option>--fields</option></term> |
| |
| <listitem><para>Print all field names currently used in all entries of the journal.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>-F</option></term> |
| <term><option>--field=</option></term> |
| |
| <listitem><para>Print all possible data values the specified field can take in all entries of the |
| journal.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>--list-boots</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> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>--disk-usage</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> |
| </varlistentry> |
| |
| <varlistentry> |
| <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> |
| |
| <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>--verify</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> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>--sync</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> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>--relinquish-var</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> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>--smart-relinquish-var</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> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>--flush</option></term> |
| |
| <listitem><para>Asks the journal daemon to flush any log data stored in |
| <filename>/run/log/journal/</filename> into <filename>/var/log/journal/</filename>, if persistent |
| storage is enabled. This call does not return until the operation is complete. Note that this call is |
| idempotent: the data is only flushed from <filename>/run/log/journal/</filename> into |
| <filename>/var/log/journal/</filename> once during system runtime (but see |
| <option>--relinquish-var</option> below), and this command exits cleanly without executing any |
| operation if this has already happened. This command effectively guarantees that all data is flushed |
| to <filename>/var/log/journal/</filename> at the time it returns.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>--rotate</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> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>--header</option></term> |
| |
| <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>--list-catalog <optional><replaceable>128-bit-ID…</replaceable></optional></option></term> |
| |
| <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" /> |
| </variablelist> |
| </refsect1> |
| |
| <refsect1> |
| <title>Exit status</title> |
| |
| <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> |
| |
| <programlisting>journalctl</programlisting> |
| |
| <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> |
| |
| <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> |
| |
| <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> |
| |
| <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 |
| |
| <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> |
| |
| <para>Show all logs generated by the D-Bus executable:</para> |
| |
| <programlisting>journalctl /usr/bin/dbus-daemon</programlisting> |
| |
| <para>Show all kernel logs from previous boot:</para> |
| |
| <programlisting>journalctl -k -b -1</programlisting> |
| |
| <para>Show a live log display from a system service <filename>apache.service</filename>:</para> |
| |
| <programlisting>journalctl -f -u apache</programlisting> |
| </refsect1> |
| |
| <refsect1> |
| <title>See Also</title> |
| <para> |
| <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>systemd-cat</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>systemd-journal-remote.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>systemd-journal-upload.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> |
| </para> |
| </refsect1> |
| </refentry> |
