The Unix command who displays a list of users who
are currently logged into a computer. The command accepts various options that
vary by system to further specify the information that is returned, such as the
length of time a particular user has been connected or what pseudo-teletype a
user is connected to. The who command is related to the command w, which
provides the same information but also displays additional data and statistics.
Example output
user11 pts/35 Apr 18 08:40 (localhost)
user12 pts/27 Apr 18 09:50 (localhost)