Here is a simple example of using SHL shift instructions to track the steps during a sequence of traffic lights. The bits pattern stored in a byte will be shifted left and the sequential steps will be activated by the corresponding memory bits. The whole process is programmed in TIA Portal, simulated on the PLCSIM, with a WinCC control panel.
Two scripts written in Bash to update all the domains and subdomains I own in automated way using Crontab. If you have dynamic IP and host a service at home, these will help you to point your DNS records at your home server(s).