ttynam, isatty - find name of terminal port; also: is unit a terminal?
character*(*) function ttynam (lunit)
logical function isatty (lunit)
The function ttynam returns a blank-padded path name of the terminal device associated with logical unit lunit.
The function isatty returns .true. if lunit is associated with a terminal device, .false. otherwise.
/dev/*, libfsu.a
The function ttynam returns an empty string (all blanks) if lunit is not associated with a terminal device in the directory /dev.