JOURNALCTL(1)                     journalctl                     JOURNALCTL(1)

       journalctl - Query the systemd journal

       journalctl [OPTIONS...] [MATCHES...]

       journalctl may be used to query the contents of the systemd(1) journal
       as written by systemd-journald.service(8).

       If called without parameters, it will show the full contents of the
       journal, starting with the oldest entry collected.

       If one or more match arguments are passed, the output is filtered
       accordingly. A match is in the format "FIELD=VALUE", e.g.
       "_SYSTEMD_UNIT=httpd.service", referring to the components of a
       structured journal entry. See systemd.journal-fields(7) 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 "+" 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).

       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 "_EXE=" match for the canonicalized
       binary path is added to the query. If a file path refers to an
       executable script, a "_COMM=" match for the script name is added to the
       query. If a file path refers to a device node, "_KERNEL_DEVICE="
       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

       Additional constraints may be added using options --boot, --unit=,
       etc., to further limit what entries will be shown (logical AND).

       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 set of journal files which will be used can be modified using the
       --user, --system, --directory, and --file options, see below.

       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 "systemd-journal",
       "adm", and "wheel" can read all journal files. Note that the two latter
       groups traditionally have additional privileges specified by the
       distribution. Members of the "wheel" group can often perform
       administrative tasks.

       The output is paged through less 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
       --no-pager option and the "Environment" section below.

       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.

       The following options are understood:

       --no-full, --full, -l
           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.

           The old options -l/--full are not useful anymore, except to undo

       -a, --all
           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.)

       -f, --follow
           Show only the most recent journal entries, and continuously print
           new entries as they are appended to the journal.

       -e, --pager-end
           Immediately jump to the end of the journal inside the implied pager
           tool. This implies -n1000 to guarantee that the pager will not
           buffer logs of unbounded size. This may be overridden with an
           explicit -n with some other numeric value, while -nall will disable
           this cap. Note that this option is only supported for the less(1)

       -n, --lines=
           Show the most recent journal events and limit the number of events
           shown. If --follow is used, this option is implied. The argument is
           a positive integer or "all" to disable line limiting. The default
           value is 10 if no argument is given.

           Show all stored output lines, even in follow mode. Undoes the
           effect of --lines=.

       -r, --reverse
           Reverse output so that the newest entries are displayed first.

       -o, --output=
           Controls the formatting of the journal entries that are shown.
           Takes one of the following options:

               is the default and generates an output that is mostly identical
               to the formatting of classic syslog files, showing one line per
               journal entry.

               is very similar, but shows timestamps in the format the
               --since= and --until= options accept. Unlike the timestamp
               information shown in short output mode this mode includes
               weekday, year and timezone information in the output, and is

               is very similar, but shows ISO 8601 wallclock timestamps.

               as for short-iso but includes full microsecond precision.

               is very similar, but shows classic syslog timestamps with full
               microsecond precision.

               is very similar, but shows monotonic timestamps instead of
               wallclock timestamps.

               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.

               shows the full-structured entry items with all fields.

               serializes the journal into a binary (but mostly text-based)
               stream suitable for backups and network transfer (see Journal
               Export Format[1] for more information). To import the binary
               stream back into native journald format use systemd-journal-

               formats entries as JSON objects, separated by newline
               characters (see Journal JSON Format[2] for more information).
               Field values are generally encoded as JSON strings, with three

                1. Fields larger than 4096 bytes are encoded as null values.
                   (This may be turned off by passing --all, but be aware that
                   this may allocate overly long JSON objects.)

                2. 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.

                3. Fields containing non-printable or non-UTF8 bytes are
                   encoded as arrays containing the raw bytes individually
                   formatted as unsigned numbers.

               Note that this encoding is reversible (with the exception of
               the size limit).

               formats entries as JSON data structures, but formats them in
               multiple lines in order to make them more readable by humans.

               formats entries as JSON data structures, but wraps them in a
               format suitable for Server-Sent Events[3].

               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
               JavaScript Object Notation (JSON) Text Sequences[4]

               generates a very terse output, only showing the actual message
               of each journal entry with no metadata, not even a timestamp.

               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.

           A comma separated list of the fields which should be included in
           the output. This only has an effect for the output modes which
           would normally show all fields (verbose, export, json, json-pretty,
           json-sse and json-seq). The "__CURSOR", "__REALTIME_TIMESTAMP",
           "__MONOTONIC_TIMESTAMP", and "_BOOT_ID" fields are always printed.

           Express time in Coordinated Universal Time (UTC).

           Don't show the hostname field of log messages originating from the
           local host. This switch only has an effect on the short family of
           output modes (see above).

       -x, --catalog
           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 Message Catalog Developer

           Note: when attaching journalctl output to bug reports, please do
           not use -x.

       -q, --quiet
           Suppresses all informational messages (i.e. "-- Logs begin at ...",
           "-- Reboot --"), any warning messages regarding inaccessible system
           journals when run as a normal user.

       -m, --merge
           Show entries interleaved from all available journals, including
           remote ones.

       -b [[ID][+-offset]|all], --boot[=[ID][+-offset]|all]
           Show messages from a specific boot. This will add a match for

           The argument may be empty, in which case logs for the current boot
           will be shown.

           If the boot ID is omitted, a positive offset will look up the boots
           starting from the beginning of the journal, and an
           equal-or-less-than zero offset will look up boots starting from the
           end of the journal. Thus, 1 means the first boot found in the
           journal in chronological order, 2 the second and so on; while -0 is
           the last boot, -1 the boot before last, and so on. An empty offset
           is equivalent to specifying -0, except when the current boot is not
           the last boot (e.g. because --directory was specified to look at
           logs from a different machine).

           If the 32-character ID is specified, it may optionally be followed
           by offset which identifies the boot relative to the one given by
           boot ID. Negative values mean earlier boots and positive values
           mean later boots. If offset is not specified, a value of zero is
           assumed, and the logs for the boot given by ID are shown.

           The special argument all can be used to negate the effect of an
           earlier use of -b.

           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.

       -k, --dmesg
           Show only kernel messages. This implies -b and adds the match

       -t, --identifier=SYSLOG_IDENTIFIER
           Show messages for the specified syslog identifier

           This parameter can be specified multiple times.

       -u, --unit=UNIT|PATTERN
           Show messages for the specified systemd unit UNIT (such as a
           service unit), or for any of the units matched by PATTERN. 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
           ("_SYSTEMD_UNIT=UNIT"), along with additional matches for messages
           from systemd and messages about coredumps for the specified unit. A
           match is also added for "_SYSTEMD_SLICE=UNIT", such that if the
           provided UNIT is a systemd.slice(5) unit, all logs of the children
           of the slice will be logged.

           This parameter can be specified multiple times.

           Show messages for the specified user session unit. This will add a
           match for messages from the unit ("_SYSTEMD_USER_UNIT=" and
           "_UID=") and additional matches for messages from session systemd
           and messages about coredumps for the specified unit. A match is
           also added for "_SYSTEMD_USER_SLICE=UNIT", such that if the
           provided UNIT is a systemd.slice(5) unit, all logs of the children
           of the unit will be logged.

           This parameter can be specified multiple times.

       -p, --priority=
           Filter output by message priorities or priority ranges. Takes
           either a single numeric or textual log level (i.e. between
           0/"emerg" and 7/"debug"), 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 syslog(3), i.e.  "emerg" (0), "alert" (1),
           "crit" (2), "err" (3), "warning" (4), "notice" (5), "info" (6),
           "debug" (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 "PRIORITY=" matches for the specified priorities.

           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 syslog(3).  --facility=help may be used
           to display a list of known facility names and exit.

       -g, --grep=
           Filter output to entries where the MESSAGE= field matches the
           specified regular expression. PERL-compatible regular expressions
           are used, see pcre2pattern(3) for a detailed description of the

           If the pattern is all lowercase, matching is case insensitive.
           Otherwise, matching is case sensitive. This can be overridden with
           the --case-sensitive option, see below.

           Make pattern matching case sensitive or case insenstive.

       -c, --cursor=
           Start showing entries from the location in the journal specified by
           the passed cursor.

           If FILE exists and contains a cursor, start showing entries after
           this location. Otherwise the show entries according the other given
           options. At the end, write the cursor of the last entry to FILE.
           Use this option to continually read the journal by sequentially
           calling journalctl.

           Start showing entries from the location in the journal after the
           location specified by the passed cursor. The cursor is shown when
           the --show-cursor option is used.

           The cursor is shown after the last entry after two dashes:

               -- cursor: s=0639...

           The format of the cursor is private and subject to change.

       -S, --since=, -U, --until=
           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 "2012-10-30 18:17:16". If the time part is
           omitted, "00:00:00" is assumed. If only the seconds component is
           omitted, ":00" is assumed. If the date component is omitted, the
           current day is assumed. Alternatively the strings "yesterday",
           "today", "tomorrow" 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.  "now" refers to the current time.
           Finally, relative times may be specified, prefixed with "-" or "+",
           referring to times before or after the current time, respectively.
           For complete time and date specification, see systemd.time(7). Note
           that --output=short-full prints timestamps that follow precisely
           this format.

       -F, --field=
           Print all possible data values the specified field can take in all
           entries of the journal.

       -N, --fields
           Print all field names currently used in all entries of the journal.

       --system, --user
           Show messages from system services and the kernel (with --system).
           Show messages from service of current user (with --user). If
           neither is specified, show all messages that the user can see.

       -M, --machine=
           Show messages from a running, local container. Specify a container
           name to connect to.

       -D DIR, --directory=DIR
           Takes a directory path as argument. If specified, journalctl will
           operate on the specified journal directory DIR instead of the
           default runtime and system journal paths.

           Takes a file glob as an argument. If specified, journalctl will
           operate on the specified journal files matching GLOB instead of the
           default runtime and system journal paths. May be specified multiple
           times, in which case files will be suitably interleaved.

           Takes a directory path as an argument. If specified, journalctl
           will operate on journal directories and catalog file hierarchy
           underneath the specified directory instead of the root directory
           (e.g.  --update-catalog will create
           ROOT/var/lib/systemd/catalog/database, and journal files under
           ROOT/run/journal or ROOT/var/log/journal will be displayed).

           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 "*" data from all namespaces is
           shown, interleaved. If the namespace identifier is prefixed with
           "+" data from the specified namespace and the default namespace is
           shown, interleaved, but no other. For details about journal
           namespaces see systemd-journald.service(8).

           Instead of showing journal contents, show internal header
           information of the journal fields accessed.

           Shows the current disk usage of all journal files. This shows the
           sum of the disk usage of all archived and active journal files.

       --vacuum-size=, --vacuum-time=, --vacuum-files=
           Removes the oldest archived journal files until the disk space they
           use falls below the specified size (specified with the usual "K",
           "M", "G" and "T" suffixes), or all archived journal files contain
           no data older than the specified timespan (specified with the usual
           "s", "m", "h", "days", "months", "weeks" and "years" suffixes), or
           no more than the specified number of separate journal files remain.
           Note that running --vacuum-size= has only an indirect effect on the
           output shown by --disk-usage, as the latter includes active journal
           files, while the vacuuming operation only operates on archived
           journal files. Similarly, --vacuum-files= might not actually reduce
           the number of journal files to below the specified number, as it
           will not remove active journal files.

           --vacuum-size=, --vacuum-time= and --vacuum-files= 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.

           These three switches may also be combined with --rotate 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.

       --list-catalog [128-bit-ID...]
           List the contents of the message catalog as a table of message IDs,
           plus their short description strings.

           If any 128-bit-IDs are specified, only those entries are shown.

       --dump-catalog [128-bit-ID...]
           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 .catalog files).

           If any 128-bit-IDs are specified, only those entries are shown.

           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.

           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 Seal= option in journald.conf(5)
           for information on Forward Secure Sealing and for a link to a
           refereed scholarly paper detailing the cryptographic theory it is
           based on.

           When --setup-keys is passed and Forward Secure Sealing (FSS) has
           already been configured, recreate FSS keys.

           Specifies the change interval for the sealing key when generating
           an FSS key pair with --setup-keys. Shorter intervals increase CPU
           consumption but shorten the time range of undetectable journal
           alterations. Defaults to 15min.

           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 --verify-key=, authenticity of the journal file
           is verified.

           Specifies the FSS verification key to use for the --verify

           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.

           Asks the journal daemon to flush any log data stored in
           /run/log/journal/ into /var/log/journal/, 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
           /run/log/journal/ into /var/log/journal once during system runtime
           (but see --relinquish-var 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
           /var/log/journal at the time it returns.

           Asks the journal daemon for the reverse operation to --flush: if
           requested the daemon will write further log data to
           /run/log/journal/ and stops writing to /var/log/journal/. A
           subsequent call to --flush causes the log output to switch back to
           /var/log/journal/, see above.

           Similar to --relinquish-var but executes no operation if the root
           file system and /var/lib/journal/ reside on the same mount point.
           This operation is used during system shutdown in order to make the
           journal daemon stop writing data to /var/log/journal/ in case that
           directory is located on a mount point that needs to be unmounted.

           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 --vacuum-size=,
           --vacuum-time= and --vacuum-file= into a single command, see above.

       -h, --help
           Print a short help text and exit.

           Print a short version string and exit.

           Do not pipe output into a pager.

       On success, 0 is returned; otherwise, a non-zero failure code is

           Pager to use when --no-pager is not given; overrides $PAGER. If
           neither $SYSTEMD_PAGER nor $PAGER are set, a set of well-known
           pager implementations are tried in turn, including less(1) and
           more(1), until one is found. If no pager implementation is
           discovered no pager is invoked. Setting this environment variable
           to an empty string or the value "cat" is equivalent to passing

           Override the options passed to less (by default "FRSXMK").

           Users might want to change two options in particular:

               This option instructs the pager to exit immediately when Ctrl+C
               is pressed. To allow less to handle Ctrl+C itself to switch
               back to the pager command prompt, unset this option.

               If the value of $SYSTEMD_LESS does not include "K", and the
               pager that is invoked is less, Ctrl+C will be ignored by the
               executable, and needs to be handled by the pager.

               This option instructs the pager to not send termcap
               initialization and deinitialization strings to the terminal. It
               is set by default to allow command output to remain visible in
               the terminal even after the pager exits. Nevertheless, this
               prevents some pager functionality from working, in particular
               paged output cannot be scrolled with the mouse.

           See less(1) for more discussion.

           Override the charset passed to less (by default "utf-8", if the
           invoking terminal is determined to be UTF-8 compatible).

           The value must be a boolean. Controls whether colorized output
           should be generated. This can be specified to override the decision
           that systemd makes based on $TERM and what the console is connected

           The value must be a boolean. Controls whether clickable links
           should be generated in the output for terminal emulators supporting
           this. This can be specified to override the decision that systemd
           makes based on $TERM and other conditions.

       Without arguments, all collected logs are shown unfiltered:


       With one match specified, all entries with a field matching the
       expression are shown:

           journalctl _SYSTEMD_UNIT=avahi-daemon.service
           journalctl _SYSTEMD_CGROUP=/user.slice/user-42.slice/session-c1.scope

       If two different fields are matched, only entries matching both
       expressions at the same time are shown:

           journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097

       If two matches refer to the same field, all entries matching either
       expression are shown:

           journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service

       If the separator "+" 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):

           journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service

       To show all fields emitted by a unit and about the unit, option
       -u/--unit= should be used.  journalctl -u name expands to a complex
       filter similar to

             + UNIT=name.service _PID=1
             + OBJECT_SYSTEMD_UNIT=name.service _UID=0
             + COREDUMP_UNIT=name.service _UID=0 MESSAGE_ID=fc2e22bc6ee647b6b90729ab34a250b1

       (see systemd.journal-fields(7) for an explanation of those patterns).

       Show all logs generated by the D-Bus executable:

           journalctl /usr/bin/dbus-daemon

       Show all kernel logs from previous boot:

           journalctl -k -b -1

       Show a live log display from a system service apache.service:

           journalctl -f -u apache

       systemd(1), systemd-journald.service(8), systemctl(1), coredumpctl(1),
       systemd.journal-fields(7), journald.conf(5), systemd.time(7), systemd-
       journal-remote.service(8), systemd-journal-upload.service(8)

        1. Journal Export Format

        2. Journal JSON Format

        3. Server-Sent Events

        4. JavaScript Object Notation (JSON) Text Sequences

        5. Message Catalog Developer Documentation

systemd 245                                                      JOURNALCTL(1)
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