Print current login name
Prints the calling user's name, as found in the file'/var/run/utmp', and exits with a status of 0.
If there is no '/var/run/utmp' entry for the calling process, 'logname' prints an error message and exits with a status of 1.
The only options are '--help' and '--version'.
"What passes for identity in America is a series of myths about one's heroic ancestors" ~ James Baldwin
groups - Print group names a user is in.
hostname - Print or set system name.
id - Print user and group id's.
uname - Print system information.
users - Print login names of users currently logged in.
who - Print who is currently logged in.
Equivalent Windows command: ECHO %username%