ix = strtoll(option_argument, &end, 10);
if(0 == strlen(option_argument) || *end)
return usage_error("ERROR: --%s must be a number\n", long_option);
ix = strtoll(option_argument, &end, 10);
if(0 == strlen(option_argument) || *end)
return usage_error("ERROR: --%s must be a number\n", long_option);