#define _FOREACH_WORD(word, length, s, separator, flags, state) \
for ((state) = (s), (word) = split(&(state), &(length), (separator), (flags)); (word); (word) = split(&(state), &(length), (separator), (flags)))
-char *strappend(const char *s, const char *suffix);
char *strnappend(const char *s, const char *suffix, size_t length);
char *strjoin_real(const char *x, ...) _sentinel_;