$ivlh_file_open vpiSysFuncVoid
$ivlh_readline vpiSysFuncVoid
$ivlh_writeline vpiSysFuncVoid
$ivlh_read vpiSysFuncVoid
$ivlh_write vpiSysFuncVoid
$ivlh_hread vpiSysFuncVoid
$ivlh_hwrite vpiSysFuncVoid