The first script that needs to be written is automating the shutdown procedure. Write a script that will perform the following tasks:
- Prompt the system administrator for all valid input parameters.
- Ask if a wall needs to be sent, and if yes, send the message.
- Ask if this is a shutdown or reboot, and process appropriately.
In addition, take this opportunity to describe the various UNIX run levels, what each level is used for, and how to boot to a specific run level.