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.