Display systemd journal for specific service since it started.
Display CPU information.
Follow data appended to a file using one of the two possible approaches.
Configure multiple IPv4 addresses on Raspberry Pi device.
Determine when the service was started and stopped using the systemd journal.
Display when the operating system was booted and calculate uptime using the systemd journal.
Read QR Code from an image.
Generate QR code to access the Wi-Fi network.