So I have been curious about one thing about systemd.
Lest say I wanted to update the time on my laptop. I use "timedatectl" command. But how did you know that the "prefix" for this command is "timedate"ctl? And not "timectl", or "datectl"?
I am guessing you can use systemctl command to list the units and targets in your Linux system? And I should find "timedatectl"?
So my point is where and how can I find the names of command when use ctl?
I hope I am making sense here.
Thanks a lot! Denny
You can use the apropos command to find commands if you aren't sure.
apropos search-string
Where search-string is along the lines of what you are looking for. Think of it as a way to grep for the commands.
To list manual pages whose title or description contains a word ending with ctl:
$ apropos 'ctl\b' _sysctl (2) - read/write system parameters alsactl (1) - advanced controls for ALSA soundcard driver apachectl (8) - Apache HTTP Server Control Interface ... You can use either of these two equivalent commands:
apropos your-command-pattern Or
man -k your-command-pattern 
