TTY.isatty(n) can be used to test if the file descriptor n is connected to a
terminal or not.
Obviously this requires knowing the "raw" file descriptor number. However, for the common use case it is easy to guess that you are considering:
- 0 : stdin
- 1 : stdout
- 2 : stderr
And this is mostly aimed at testing of stdout is being piped elsewhere, or is
connected to a terminal that supports colour, or other specialised terminal
operations.
The library also contains a range of ANSI constants for common colours, or
common modes e.g. bold, underline, reset.