[Lazarus] Startup environment: to Gui, or not to GUI?

[Henry Vermaak]

On Tue, Apr 11, 2017 at 09:15:16AM +0000, Mark Morgan Lloyd via Lazarus wrote:
> Apologies if this is an FAQ.
> 
> Is there an orthodox way that a Lazarus program can very early on look at
> how it's been started and decide whether it can usefully fall back to a text
> mode, e.g. to display help info on stdout rather than a messagebox?

isatty() is traditionally used for this on POSIX operating systems.
It's in unit termio.

Henry