> I did not see on the documentation information about
> the return values of httrack.exe.
> Does it return any values there is error or when
> robots.txt stop the download process immediately ?
No - the only case when main() returns a non-zero code is when the arguments
are invalid (invalid option, for example)

All other cases return 0, even if the site is down.

However, when continuing/updating a mirror, httrack will (attempt) to detect
these cases and will restore th eprevious cache session.