logname

Print login name

$ logname

logname [options]

logname prints the user's login name. It reads from the utmp file to determine the original login.
Unlike whoami, logname shows the login name even after su or sudo commands.

--help

Display help information.

Display version information.

May fail if not run from a terminal. Differs from whoami after su. POSIX standard command.

logname is a traditional Unix command from POSIX, showing the name used to log into the system.

whoami(1), who(1), id(1)