Availability:C-language interface function
const char* PL_atom_chars(atom_t 
atom)Return a C-string for the text represented by the given atom. The 
returned text will not be changed by Prolog. It is not allowed to modify 
the contents, not even `temporary' as the string may reside in read-only 
memory. The returned string becomes invalid if the atom is garbage 
collected (see section 
11.4.2.1). Foreign functions that require the text from an atom 
passed in a term_t normally use
PL_get_atom_chars() 
or PL_get_atom_nchars().