private void processEncodingOption(String value) {
String[] encodings = value.split(":", 3);
switch (encodings.length) {
case 3:
throw new MainExitException(1, "extra argument for -E: " + encodings[2]);
case 2:
config.setInternalEncoding(encodings[1]);
case 1:
config.setExternalEncoding(encodings[0]);
// Zero is impossible