Linux Survival Basics
Read-onlyCheck Whether a Service Starts at Boot
A service is manually started during an incident, but nobody verifies whether systemd will start it after reboot.
Command
systemctl is-enabled nginxBefore you run this
System impact: Read-only. Low when scoped to the shown target.
When not to use it: Do not use it to check whether the service is currently running; use systemctl is-active for that.
Expected output
enabled
System impact
Read-only. Nothing changes. systemctl prints enabled, disabled, static, masked, or another enablement state.
Recovery / rollback: no state is changed.
When to use it
Use after installing services, recovering incidents, or manually starting daemons.
When not to use it
Do not use it to check whether the service is currently running; use systemctl is-active for that.
Watch this command run
Command transcript
This sanitized transcript shows the commands and output shape without exposing host details.
$ systemctl is-enabled nginx
enabled$ systemctl is-active nginx
activeView commands shown
These are the commands shown in the sanitized transcript.
Commands shown
systemctl is-enabled nginxsystemctl is-active nginx
next steps
Related commands
Inspect One Service Without Pager Traps
Make systemctl status safe for scripts, screenshots, and quick incident notes.
systemctl status nginx --no-pager --lines=30
Check If a Service Is Active
Get a clean yes-or-no service state without the full status page.
systemctl is-active nginx
Read Current-Boot Logs for One Service
Ignore stale logs and inspect only what happened since this boot.
journalctl -u nginx -b --no-pager -n 80
Print the Exact systemd Exit Fields
Turn a noisy service failure into four fields you can paste into an incident note.
systemctl show app-worker --property=Result,ExecMainCode,ExecMainStatus,NRestarts --no-pager
Read the Failure Cause in systemctl Status
The status page often tells you the failed startup step before you open every log.
systemctl status app-worker --no-pager --lines=50
Study mapping
Use this as independent command practice: read the notes, predict the output, then compare it with the example before using a real shell.
Useful for
- LPIC-1 style command-line practice
- LFCS style performance tasks
- Linux+ style troubleshooting review
Independent study support only. No affiliation, endorsement, exam dumps, or real exam questions.