isInputTty

True if the input is connected to the TTY.

If the program is running interactively this will (usually) be true, and it means readInput will come from the terminal. If the user has piped the output of another program into this one, explicitly redirected data to the input stream, or is simply running this program in a non-interactive context (such as within an IDE, build tool, or headlessly), this will be false.