If you’re fairly new to Linux, you might need some help getting started on the command line. But you made it here, so let’s run through a number of ways that you can get comfortable and up to speed fairly quickly.
Every Linux command should have a “man page” (i.e., manual page) – an explanation of what the command does, how it works and the options that you can use to specify what you want the command to show you. For example, if you wanted to see the options for formatting the output of the date command, you should look at the man page with the command “man date”. It should among other things, show you the format of the date command like this:
Source:: Network World – Linux