journalctlsystemdDeveloperLennartPoetteringlennart@poettering.netjournalctl1journalctlsystemd-journalctlQuery the systemd journaljournalctl OPTIONSMATCHDescriptionjournalctl may be
used to query the contents of the
systemd1
journal.If called without parameter will show the full
contents of the journal, starting with the oldest
entry collected.If a match argument is passed the output is
filtered accordingly. A match is in the format
FIELD=VALUE,
e.g. _SYSTEMD_UNIT=httpd.service.Output is interleaved from all accessible
journal files, whether they are rotated or currently
being written, and regardless 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 adm
group get access to the system journal and the
journals of other users.OptionsThe following options are understood:Prints a short help
text and exits.Prints a short version
string and exits.Do not pipe output into a
pager.Show all fields in
full, even if they include unprintable
characters or are very
long.Show only most recent
journal entries, and continously print
new entries as they are appended to
the journal.Controls the number of
journal lines to show, counting from
the most recent ones. Takes a positive
integer argument. In follow mode
defaults to 10, otherwise is unset
thus not limiting how many lines are
shown.Show all stored output
lines, even in follow mode. Undoes the
effect of
.Controls the
formatting of the journal entries that are
shown. Takes one of
short,
short-monotonic,
verbose,
export,
json,
cat. short
is the default and generates an output
that is mostly identical to the
formatting of classic syslog log
files, showing one line per journal
entry. short-monotonic
is very similar but shows monotonic
timestamps instead of wallclock
timestamps. verbose
shows the full structered entry items
with all
fiels. export
serializes the journal into a binary
(but mostly text-based) stream
suitable for backups and network
transfer. json
formats entries as JSON data
structures. cat
generates a very terse output only
showing the actual message of each
journal entry with no meta data, not
even a timestamp.Suppresses any warning
message regarding inaccessable system
journals when run as normal
user.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. Will print the new ID in
three different formats which can be
copied into source code or
similar.Exit statusOn success 0 is returned, a non-zero failure
code otherwise.Environment$SYSTEMD_PAGERPager to use when
is not given;
overrides $PAGER. Setting
this to an empty string or the value
cat is equivalent to passing
.See Alsosystemd1,
systemctl1,
systemd-journald.conf5