Linux Survival Basics

Print the Exact systemd Exit Fields

Full status output is useful for humans, but incident notes and scripts need compact fields like Result, ExecMainStatus, and restart count.

Command

systemctl show app-worker --property=Result,ExecMainCode,ExecMainStatus,NRestarts --no-pager

What changed

Nothing changes. systemctl show prints selected unit properties.

Danger

safe

When to use it

Use when documenting a failure, comparing before and after recovery, or writing a runbook check.

When not to use it

Do not treat numeric status values as self-explanatory; pair them with status or journal lines.

Undo or recovery

No undo needed because the command is read-only.

Expected output

Result, ExecMainCode, ExecMainStatus, and NRestarts property lines.

demo script

Disposable terminal steps

systemctl status app-worker --no-pager --lines=50
systemctl show app-worker --property=Result,ExecMainCode,ExecMainStatus,NRestarts --no-pager

Terminal transcript Demo JSON

simulated output

What it looks like

disposable vessel

::fixture-ready::
$ systemctl status app-worker --no-pager --lines=50
● app-worker.service - Background job worker
     Loaded: loaded (/etc/systemd/system/app-worker.service; enabled; preset: enabled)
    Drop-In: /etc/systemd/system/app-worker.service.d
             └─override.conf
     Active: failed (Result: exit-code) since Thu 2026-06-25 14:22:17 CDT; 4min ago
   Duration: 1.243s
    Process: 2144 ExecStart=/srv/app/bin/worker --queue default (code=exited, status=217/USER)
   Main PID: 2144 (code=exited, status=217/USER)
        CPU: 38ms

Jun 25 14:22:17 vps systemd[1]: Started app-worker.service - Background job worker.
Jun 25 14:22:17 vps systemd[2144]: app-worker.service: Failed to determine user credentials: No such process
Jun 25 14:22:17 vps systemd[2144]: app-worker.service: Failed at step USER spawning /srv/app/bin/worker: No such process
Jun 25 14:22:17 vps systemd[1]: app-worker.service: Main process exited, code=exited, status=217/USER
Jun 25 14:22:17 vps systemd[1]: app-worker.service: Failed with result 'exit-code'.
::exit-code::0
$ systemctl show app-worker --property=Result,ExecMainCode,ExecMainStatus,NRestarts --no-pager
Result=exit-code
ExecMainCode=1
ExecMainStatus=217
NRestarts=5
::exit-code::0

YouTube Short

Print compact failure fields.

For incident notes, ask systemd for the exact failure fields instead of copying a whole status page.

experiments

A/B tests to run

Metric: short_click_through_rate

A: Turn service failure into four fields.

B: Cleaner incident notes for failed units.