The Complete 2026 Guide to Nginx Commands

1. Basic Service Control Commands

The most important commands to start, stop, and restart Nginx are: nginx or systemctl start nginx Starts the Nginx master and worker processes. nginx -s stop Immediately kills worker processes, which may drop requests. nginx -s quit Waits for current requests to finish before exiting.

Recommended for production because it shuts down gracefully. systemctl restart nginx Equivalent to a stop followed by a start.

2. Smooth Reload (Zero‑Downtime Update)

nginx -s reload

Core mechanism:

Does not stop the service.

Worker processes are switched smoothly.

Configuration updates are applied without downtime.

3. Reopen Log Files

nginx -s reopen

Used for log rotation and to prevent log loss.

4. Configuration Check Commands

nginx -t

Example output:

nginx: configuration file /etc/nginx/nginx.conf test is successful

To check a specific configuration file: nginx -t -c /etc/nginx/nginx.conf Purpose: verify multi‑environment configurations.

5. View Compile Parameters

nginx -V

Shows compiled modules, path information, and version details.

6. Process Management

List Nginx processes: ps -ef | grep nginx Typical structure shows a master process and one or more worker processes.

Show master PID: cat /run/nginx.pid or cat /var/run/nginx.pid Manually kill a process (use with caution): kill -9 <pid> May cause connection interruptions.

Does not close gracefully.

7. Log Viewing (Troubleshooting Core)

Real‑time access log: tail -f /var/log/nginx/access.log Real‑time error log: tail -f /var/log/nginx/error.log Filter error messages:

grep "error" /var/log/nginx/error.log

8. Status and Performance Metrics

Enable stub_status in the Nginx configuration:

location /nginx_status {
    stub_status;
}

Query the status endpoint: curl http://localhost/nginx_status Typical output includes active connections, accepts, handled, requests, and the numbers of reading, writing, and waiting connections.

These commands together form a practical reference for operating and troubleshooting Nginx in production environments.