LOGNAME(1) BSD Reference Manual LOGNAME(1)
logname - display user's login name
logname
The logname utility writes the user's login name to standard output fol- lowed by a newline ('\n'). The logname utility explicitly ignores the LOGNAME and USER environment variables because the environment cannot be trusted. The logname utility exits 0 on success or >0 if an error occurred.
who(1), whoami(1), getlogin(2)
The logname utility conforms to IEEE Std 1003.2-1992 ("POSIX.2").
The logname command appeared in 4.4BSD. MirBSD #10-current June 9, 1993 1