Service restart has been a solved problem in UNIX for over 40 years. It is called inetd. It is not perfect, and it was originally created for a slightly differe

Service restart has been a solved problem in UNIX for over 40 years. It is called inetd. It is not perfect, and it was originally created for a slightly different operating model, but it does restart crashed «services». They are, in fact, called daemons. Shell scripts are for manual service starts, stops and restarts (when the daemon does not support a restart on SIGHUP), they are not meant for the automated service restarts. Different UNIX systems have gone on to replace inetd to address specific shortcomings of the inetd model with launchd, service management facility, systemd, SAM, but the service restart is not an innovation that systemd has brought along. It is a further, fine-grained, improvement over a decade old concept and a tool + ecosystem that has implemented the concept (inetd + rc scripts).