I am currently trying to build a very basic serial shell with my arduino.

I am able to get an output from the device using Serial.read() and can get the character it has outputted, but I cannot work out how to then add that character to a longer to form the full command.

I tried the logical thing but it doesn't work:

char Command[];

void loop(){
  if(Serial.available() > 0){
    int clinput = Serial.read();
    Command = Command + char(clinput);
}

Can anybody help? Thank You.