Displays the username and domain for the currently logged in user.

The whoami output is the same as the 2 environment variables %USERDOMAIN% and %USERNAME%.

So the same output can usually be achieved with

ECHO %USERDOMAIN%\%USERNAME%

One exception to this is when using RUNAS /env , e.g. if my username is Simon:

c:>RunAs /env /user:JDoe cmd.exe
c:>ECHO %USERDOMAIN%\%USERNAME%
ss64\Simon

c:>whoami
ss64\JDoe

Under Windows 2000 there is an additional switch WHOAMI /all - this shows all permissions and group memberships.