-UI_get0_result_string() returns the UI string action description
-string for B<UIT_PROMPT> and B<UIT_VERIFY> type UI strings, NULL for
-any other type.
+UI_get0_result_string() returns the UI string result buffer for
+B<UIT_PROMPT> and B<UIT_VERIFY> type UI strings, NULL for any other
+type.
+
+UI_get_result_string_length() returns the UI string result buffer's
+content length for B<UIT_PROMPT> and B<UIT_VERIFY> type UI strings,
+-1 for any other type.