Repeatedly execute a command at intervals and display output.
low risk
watch runs a command every N seconds (default 2) and displays its output full-screen, highlighting changes. Perfect for monitoring dynamic state like pod counts, resource usage, or deployment rollouts without writing a custom loop.
| Flag | Meaning |
|---|---|
-n --interval | Set update interval in seconds |
-d --differences | Highlight changes since last update |
-g --chgexit | Exit when output changes |
-e --errexit | Freeze on command error |
watch -n 2 'kubectl get pods'Monitor pod status every 2 seconds · explain & risk-check →watch -d -n 1 'df -h /var'Watch disk usage with change highlighting · explain & risk-check →watch -n 5 'ss -tunlp | grep :8080'Watch for port listener · explain & risk-check →watch -g 'kubectl get deploy myapp -o jsonpath="{.status.readyReplicas}"'Exit when deployment scale changes · explain & risk-check →Use `watch -d` during rolling deployments to instantly spot when pod statuses change — the highlighting makes it obvious without having to scan all rows manually.
Reference text is hand-written and may be incomplete — check man watch for your version. Test destructive commands on a non-production system first.