If you're running systemd (most Linux distributions released in the last couple of years do), then the absence of systemctl
suggests that you've seriously broken your system. In that case nobody can say for sure (given the information in the question) whether your system will even come back up after a reboot.
If you're not running systemd (because you either replaced it or are running a distribution which doesn't use systemd), you're following a guide that is not suitable for your setup. Without more knowledge of your setup we can't say whether your change will have any effect in that case.
Please edit the following information into your question:
- What Linux distribution (including version) do you use?
- What have you done to systemd – or what might have happened that has caused the absence of
systemctl
?
- What are you trying to achieve?
systemctl restart
does the same thing to a service that reboot does.