#include <wchar.h> wchar_t *wcstok(wchar_t *wcs, const wchar_t *delim, wchar_t **ptr);
The search starts at wcs, if wcs is not NULL, or at *ptr, if wcs is NULL. First, any delimiter wide-characters are skipped, that is, the pointer is advanced beyond any wide-characters which occur in delim. If the end of the wide-character string is now reached, wcstok() returns NULL, to indicate that no tokens were found, and stores an appropriate value in *ptr, so that subsequent calls to wcstok() will continue to return NULL. Otherwise, the wcstok() function recognizes the beginning of a token and returns a pointer to it, but before doing that, it zero-terminates the token by replacing the next wide-character which occurs in delim with a Laq\0aq character, and it updates *ptr so that subsequent calls will continue searching after the end of recognized token.
wchar_t *wcs = ...;
wchar_t *token;
wchar_t *state;
for (token = wcstok(wcs, " \t\n", &state);
token != NULL;
token = wcstok(NULL, " \t\n", &state)) {
...
}