LFCS Admin Exam preparation guide series, main page can be found here.
This post is part of Essential Commands from the domain competency list for the exam. The full list can be found in the link above paragraph or the Linux Foundation page here.
As system administrators, we need to remember many details about commands, what the operators we can use, how we should run this command. It is lots of things to remember. Likely as any operating system, Linux comes with the documentation we can use, so we don’t need to remember everything. Because of that, we should know how to use this documentation; this is what we are going to talk about in this blog.
Every command has man page, which helps us understand the command, all man pages are build in the same way. They contain NAME with a command name, SYNOPSIS with how to use the command and DESCRIPTION with a detailed explanation of what the command does, what arguments, and options we can use.
There are few commands which do not have man page, for example, cd, type, alias.
Info pages provide more detailed info about the commands present to us in info format and can contain links to different parts of the document to make navigation more manageable. We can use the space bar to move by page or the navigation arrow on the keyboard. When we see the link we want to navigate to, we move the cursor to the link and press Enter. To exit back to terminal we press Q.
Another option which everyone should know is the command help option, and we use it by taping the command and –help. The help option displays command usage information, as well as the arguments we can use with the command.
whatis is a command which helps to list short description about the command. We use it by taping whatis <command>. Again there are some commands which do not have anything to display with this command, like cd, type, alias.
All these above can help us a lot when we are not sure what the command does or how to use it.
That is all for today, thank you for reading.