Perform TERM check for file writers only

)

func isSmartTerminal(w io.Writer) bool {

	if f, ok := w.(*os.File); ok {

		if term, ok := os.LookupEnv("TERM"); ok && term == "dumb" {

			return false

		}

	if f, ok := w.(*os.File); ok {

		var termios syscall.Termios

		_, _, err := syscall.Syscall6(syscall.SYS_IOCTL, f.Fd(),

			ioctlGetTermios, uintptr(unsafe.Pointer(&termios)),