If you want to view the log for a systemd service you can use the journalctl command. Basic Log Viewing: To view the logs for your prog-app service, you can use the following command:

sudo journalctl -u service-app

Tail Logs: If you want to follow the log in real-time, as new entries are added, use the -f flag:

sudo journalctl -fu service-app

Filter by Time: If you’re interested in logs from a specific time period, you can use --since and --until options. For example:

sudo journalctl -u service-app --since "2023-11-27" --until "2023-11-28"

Viewing the Most Recent Entries: To see the most recent entries, you can combine journalctl with other commands like tail. For example:

sudo journalctl -u service-app | tail -n 20