extern jb_err string_append(char **target_string, const char *text_to_append);
extern jb_err string_join (char **target_string, char *text_to_append);
extern char *string_toupper(const char *string);
+extern char *string_tolower(const char *string);
extern void string_move(char *dst, char *src);
extern char *chomp(char *string);