This article covers the who command in Linux along with its some of the useful command line options.
Sometimes, while working on the command line, you might want to know more about logged in users.
There exists a command line utility who which you can use to access this kind of information.
Basically, the who command shows who all are logged in.
Here's its syntax:
$ who [OPTION]... [ FILE | ARG1 ARG2 ]
To access time of last system boot?
For this, use the -b command line option:
$ who -b