Temporary implementation of %s formatter

examples/printf.c

@@ -19,8 +19,8 @@ int main()
 {
     memset(buffer, '\0', sizeof(buffer));
     buffer_index = 0;
-    kernaux_printf(my_putchar, "Hello, World!");
-    assert(strcmp(buffer, "Hello, World!") == 0);
+    kernaux_printf(my_putchar, "Hello, %s!", "Alex");
+    assert(strcmp(buffer, "Hello, Alex!") == 0);
 
     return 0;
 }

src/printf.c

@@ -19,7 +19,21 @@ void kernaux_printf_va(
     for (const char *current_ptr = format; *current_ptr; ++current_ptr) {
         const char current = *current_ptr;
 
-        putchar(current);
+        if (current != '%') {
+            putchar(current);
+            continue;
+        }
+
+        if (*(++current_ptr) == 's') {
+            const char *const arg = va_arg(va, const char*);
+
+            for (const char *arg_ptr = arg; *arg_ptr; ++arg_ptr) {
+                putchar(*arg_ptr);
+            }
+        }
+        else {
+            break;
+        }
     }
 
     putchar('\0');