Questions

1. You want to create a graphical user interface for a shell script that will run on a wide variety of Linux, Unix, and Unix-like operating systems. Which of the follow utilities would you use for best availability?
   1. zenity
   2. cdialog
   3. xdialog
   4. yad
2. Which of the following statements is true about this code snippet?

command -v Xdialog
if [[ -n $DISPLAY ]] && [[ $? == 0 ]]; then
        diag=Xdialog
else
        diag=dialog
fi

1. It’s good code, and will work just fine.
2. It won’t work, because it uses the wrong method to detect if the Xdialog executable is present.
3. It won’t work, because it’s not possible to detect if a certain executable is present.
4. It won’t work, because having the [[ -n $DISPLAY ]] test come first ensures that $? always returns a value of 0.