Instead of using index() macro defined to strchr, use C99 strchr.
Instead of using rindex() macro defined to strrchr, use C99 strrchr.
If you want to try building on a platform that doesn't offer those
two functions, these are available:
define NOT_C99 /* to make some non-C99 code available */
define NEED_INDEX /* to define a macro for index() */
define NEED_RINDX /* to define a macro for rindex() */