pPretty detected tty for whether to enable color or not

[juhp]

For example if one outputs to a pipe, file or Emacs shell-command etc, then the ANSI color control characters are visible , so it would be better to detect whether one is using a TTY terminal or not and depending on that decide whether to enable color or not in the default output.

One can do this by using say https://hackage.haskell.org/package/base-4.12.0.0/docs/System-IO.html#v:hIsTerminalDevice

[cdepillabout]

This sounds like a good idea to me. I'd be willing to accept a PR implementing this.

It would also be nice to make it an option so the end user could configure this.

This shouldn't be too hard, so I'll mark it beginner friendly.

[metiulekm]

If nobody else feels like doing so, I will try doing this in the evening (GMT+2).

We should probably add functions that always print colored output, even outside TTYs, and also the tracing functions should somehow do the detection too, right?