chiark-really - 6.1.2+nmu1 main

really is a program that allows certain users to become whatever user
they like on request. It is a bit like sudo in that respect.
However, really is simpler than sudo, and doesn't give the system
administrator any false security promises. So really is less of a
general security risk to the system.
.
Unlike sudo it does not pretend that the called account can be any
more secure than the calling account, so there is never a need for a
password. If you wanted to restrict which commands and functions the
called user can perform, use userv, not really or sudo.
.
Also unlike sudo, really only works if the calling user is supposed
to be equivalent to root. But, really can also be used by
root-equivalent users to become any user, not just root; in this way
it can be a replacement for certain uses of su.