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       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, if
       the character "+" appears as separate word on the command line, all
       matches before and after are combined in a disjunction (i.e. logical

       As shortcuts for a few types of field/value matches, file paths may be
       specified. If a file path refers to an executable file, this is
       equivalent to an "_EXE=" match for the canonicalized binary path.
       Similarly, if a path refers to a device node, this is equivalent to a
       "_KERNEL_DEVICE=" match for the device.

       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.

       All users are granted access to their private per-user journals.
       However, by default, only root and users who are members of the
       "systemd-journal" group get access to the system journal and the
       journals of other users.

       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 --no-pager
       and section Environment below.

       When outputing 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, and other lines are displayed normally.


       The following options are understood:

       -h, --help
           Prints a short help text and exits.

           Prints a short version string and exits.

           Do not pipe output into a pager.

       -l, --full
           Show all (printable) fields in full.

       -a, --all
           Show all fields in full, even if they include unprintable
           characters or are very long.

       -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 on the command line. Note
           that this option is only supported for the less(1) pager.

       -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, a
           positive integer, is optional, and defaults to 10.

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

       -r, --reverse
           Reverse output, so 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 ISO 8601 wallclock timestamps.

               is very similar, but shows timestamps with full microsecond

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

               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).

               formats entries as JSON data structures, one per line (see
               Journal JSON Format[2] for more information).

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

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

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

       -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 any warning message regarding inaccessible system
           journals when run as normal user.

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

           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 a
           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 the chronological order, 2 the second and so on; while
           -0 is the last boot, -1 the boot before that, 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 a 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.

           Show a tabular list of boot numbers (relative to 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

       -u, --unit=
           Show messages for the specified systemd unit. This will add a match
           for messages from the unit ("_SYSTEMD_UNIT=") and additional
           matches for messages from systemd and messages about coredumps for
           the specified unit.

           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.

           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.

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

           Start showing entries from the location in the journal after the
           location specified by the this 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 this the cursor is private and subject ot change.

       --since=, --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.

       -F, --field=
           Print all possible data values the specified field can take 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.

       -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 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 argument. If specified, journalctl will
           operate on catalog file hierarchy underneath the specified
           directory instead of the root directory (e.g.  --update-catalog
           will create ROOT/var/lib/systemd/catalog/database).

           Instead of showing journal contents, generate a new 128 bit ID
           suitable for identifying messages. This is intended for usage by
           developers who need a new identifier for a new message they
           introduce and want to make recognizable. This will print the new ID
           in three different formats which can be copied into source code or

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

           Shows the current disk usage of all journal files.

       --list-catalog [128-bit-ID...]
           List the contents of the message catalog, as 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 has already
           been set up, 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


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


           Pager to use when --no-pager is not given; overrides $PAGER.
           Setting this to an empty string or the value "cat" is equivalent to
           passing --no-pager.


       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

       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

       Show all logs generated by the D-Bus executable:

           journalctl /usr/bin/dbus-daemon

       Show all logs of the kernel device node /dev/sda:

           journalctl /dev/sda

       Show all kernel logs from previous boot:

           journalctl -k -b -1


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


        1. Journal Export Format

        2. Journal JSON Format

        3. Server-Sent Events

        4. Message Catalog Developer Documentation

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