char *strrchr_m(const char *s, char c);
char *strnrchr_m(const char *s, char c, unsigned int n);
char *strstr_m(const char *src, const char *findstr);
-void strlower_m(char *s);
+bool strlower_m(char *s);
bool strupper_m(char *s);
size_t strlen_m(const char *s);
size_t strlen_m_term(const char *s);