The one option is to use output formatting options. For example journalctl -o verbose
will show you all data connected to a particular entry. Example:
Wed 2017-02-08 21:06:27.524361 EET [s=f689734c6c674cfd98a49e66c3349fdd;i=42c;b=01111969442644239da701153bd49c37;m=23e9195;t=548098fc53333;x=c943c53e7411726]
PRIORITY=6
SYSLOG_FACILITY=3
CODE_FILE=src/core/job.c
CODE_LINE=804
CODE_FUNCTION=job_log_status_message
SYSLOG_IDENTIFIER=systemd
MESSAGE_ID=39f53479d3a045ac8e11786248231fbf
USER_UNIT=timers.target
MESSAGE=Reached target Timers.
RESULT=done
_TRANSPORT=journal
_PID=874
_UID=1000
_GID=1000
_COMM=systemd
_EXE=/usr/lib/systemd/systemd
_CMDLINE=/usr/lib/systemd/systemd --user
_CAP_EFFECTIVE=0
_SYSTEMD_CGROUP=/user.slice/user-1000.slice/user@1000.service/init.scope
_SYSTEMD_OWNER_UID=1000
_SYSTEMD_UNIT=user@1000.service
_SYSTEMD_USER_UNIT=init.scope
_SYSTEMD_SLICE=user-1000.slice
_SYSTEMD_USER_SLICE=-.slice
_SYSTEMD_INVOCATION_ID=2f397502a38947d5b18eca7eb5f5b1ba
_SOURCE_REALTIME_TIMESTAMP=1486580787524361
_BOOT_ID=01111969442644239da701153bd49c37
_MACHINE_ID=4de8a7d0aad84611b2e1dfb0ff8f43e7
_HOSTNAME=dracula
Here field PRIORITY
actually points to a message level (in this particular case it's INFO
level). Levels map in this way:
0: emerg
1: alert
2: crit
3: err
4: warning
5: notice
6: info
7: debug
I don't think you can avoid other metadata and only leave message level (correct me if I'm wrong) without some kind of post-processing (custom shell script etc).