1. Why do we need an exit status?
2. What is the difference between exit status, exit code, and return code?
3. Which flag do we use with test to test for the following?
   • An existing directory
   • A writable file
   • An existing symbolic link
4. What is the preferred shorthand syntax for test -d /tmp/?
5. How can we print debug information in a Bash session?
6. How can we check whether a variable has content?
7. What is the Bash format for grabbing a return code?
8. Of || and &&, which is the logical AND and which is the OR?
9. What is the Bash format for grabbing the number of arguments?
10. How can we make sure that it does not matter from which working directory the user calls the script?
11. How do Bash parameter expansions help us when dealing with user input?