Print login names of users currently logged in, print on a single
line a blank-separated list of user names of users currently logged in to the
SYNTAX users [FILE] With no FILE argument, `users' extracts its information from the file `/var/run/utmp'. If a file argument is given, `users' uses that file instead. A common choice is `/var/run/wtmp'. The only options are `--help' and `--version'.
Each user name corresponds to a login session, so if a user has more than one login session, that user's name will appear the same number of times in the output.
groups - Print group names a user is in
hostname - Print or set system name
id - Print user and group id's
logname - Print current login name
printenv - Print environment variables.
uname - Print system information
who - Print who is currently logged in
whoami - Print the current user id and name (`id -un')