SWI-Prolog -- API-function PL_get

Availability:C-language interface function

bool PL_get_atom(term_t +t, atom_t *a)

If t is an atom, store the unique atom identifier over a. See also PL_atom_chars() and PL_new_atom(). If there is no need to access the data (characters) of an atom, it is advised to manipulate atoms using their handle. As the atom is referenced by t, it will live at least as long as t does. If longer lifetime is required, the atom should be locked using PL_register_atom().