Given a UNIX tty name, this function retrieves the respective channel
status.
Parameters:
tty - a UNIX tty name minus "/dev/".
status - a pointer to a channel_status_t status block where the
channel status will be stored.
Returns:
if the status of the channel cannot be read from the status file,
-1 is returned and the default line status
(LST_NORMAL,LSR_OK,0,"[NO-USER]") is copied to status. If all
goes well, 1 is returned.