cats_strings: new helper function for safely accessing the nth string

src/cats_strings/cats_strings.c

@@ -136,6 +136,17 @@ struct string_array *new_string_array()
         return result;
 }
 
+const char *get_nth_string_from_array(const struct string_array *array, int n)
+{
+        assert(array != NULL);
+        if (n < 0 && n >= array->count) {
+                log_message(LOG_ERROR, "%s: requested string index %d out of range [0, %d]", __func__ , n, array->count);
+                exit(EXIT_FAILURE);
+        }
+
+        return array->string[n];
+
+}
 
 struct string_array *new_string_array_init(const char *entry)
 {

src/cats_strings/cats_strings.h

@@ -88,7 +88,7 @@ void string_array_add_double(struct string_array *array, double number, const ch
 
 void
 string_array_add_int_conditional(struct string_array *array, int32_t number, const char *format_string, bool condition);
-
+const char *get_nth_string_from_array(const struct string_array *array, int n);
 void print_string_array(const struct string_array *array);
 
 char *remove_0th_token(char *line, const char *sep);