In Activity Monitor there is a cryptic menu option to Send Signal to Process. Have you ever wondered what it was? If you select it, you’ll see obscure terms like SIGINT and SIGHUP, which doesn’t exactly clear things up. So what exactly are these signals? Those signals are a result of the Unix foundation at the heart of macOS. Terminal has some of these signals built-in: when you hit Ctrl + C to stop a running command, you are sending the process SIGINT to interrupt and stop the currently running command. They were one of the first ways apps could communicate with each other and are part…
Read the full article: Troubleshoot Mac Apps the Old Fashioned Way With POSIX Signals