memccpy
void *memccpy(void *, const void *, int, size_t);
ATF_CHECK(memccpy(buf, "foo bar", c, sizeof(buf)) != NULL);
ATF_CHECK(memccpy(buf, "foo bar", '\0', sizeof(buf) - 1) != NULL);
ATF_CHECK(memccpy(buf, "foo bar", 'x', 7) == NULL);
ATF_CHECK(memccpy(buf, "xxxxxxx", 'r', 7) == NULL);