Note that once an atom name is specified for the first time it is automatically made known to the system, so calls to current_atom/1 with any atom as an argument will always succeed.
Success:
   current_atom(eclipse).
   current_atom(anything).
   current_atom('My atom').
   [eclipse]: current_atom(X).
   X = []    More? (;)         % RETURN pressed
   yes.
   [eclipse]:
Error:
   current_atom(1).           Error 5.
   current_atom(man(1)).      Error 5.