STRTOK has similar semantics as the standard C/C++ library STRTOK function.
If instring contains fewer tokens than tokennum, the function returns NULL.
If either instring or delimiter is NULL, the function returns NULL.
STRTOK has similar semantics as the standard C/C++ library STRTOK function.
If instring contains fewer tokens than tokennum, the function returns NULL.
If either instring or delimiter is NULL, the function returns NULL.