linux – 如何判断用户是否选择“Run In Terminal”

if [ -t 1 ]; then
  echo "Standard output is a terminal."
  echo "This means a terminal is available,and the user did not redirect the script's output."
fi

if [ -t 2 ]; then
  echo "Standard error is a terminal." >&2
  echo "If you're going to display things for the user's attention,standard error is normally the way to go." >&2
fi

if tty >/dev/null; then
  echo "Standard input is a terminal." >$(tty)
  echo "The tty command returns the name of the terminal device." >$(tty)
fi

echo "This message is going to the terminal if there is one." >/dev/tty
echo "/dev/tty is a sort of alias for the active terminal." >/dev/tty
if [ $? -ne 0 ]; then
  : # Well,there wasn't one.
fi

if [ -n "$DISPLAY" ]; then
  xmessage "A GUI is available."
fi