Add the family of printf, scanf functions

src/lib.rs

@@ -166,6 +166,16 @@ extern {
                    mode: c_int,
                    size: size_t) -> c_int;
     pub fn setbuf(stream: *mut FILE, buf: *mut c_char);
+
+    pub fn fprintf(stream: *mut FILE, format: *const c_char, ...) -> c_int;
+    pub fn printf(format: *const c_char, ...) -> c_int;
+    pub fn snprintf(s: *mut c_char, n: size_t,
+                    format: *const c_char, ...) -> c_int;
+    pub fn sprintf(s: *mut c_char, format: *const c_char, ...) -> c_int;
+    pub fn fscanf(stream: *mut FILE, format: *const c_char, ...) -> c_int;
+    pub fn scanf(format: *const c_char, ...) -> c_int;
+    pub fn sscanf(s: *const c_char, format: *const c_char, ...) -> c_int;
+
     pub fn fgetc(stream: *mut FILE) -> c_int;
     pub fn fgets(buf: *mut c_char, n: c_int, stream: *mut FILE) -> *mut c_char;
     pub fn fputc(c: c_int, stream: *mut FILE) -> c_int;