Using the vi editor, write a Unix shell script (NOT a C program) on the Sun cluster that obeys the following specifications. Shell scripts are described on pages 283 - 293 of the text. Your shell script should:

• display the contents of the current working directory on the screen, one page at a time
• display a menu giving the user the choice of displaying the contents of a file; counting the characters, words and lines in a file; changing directories; or exiting.
• prompt the user for menu selection. This can be done by numbering the menu selections and having the user enter a number, or by having the user enter a letter or keyword selection.
• handle each selection as follows:
  • if the user selects displaying the contents of a file, prompt the user for a filename. If the file exists, display its contents one page at a time. If the file does not exist, print an error message.
  • if the user selects counting the characters, words and lines in a file, prompt the user for a file name. If the file exists, find and display the number of characters, words and lines in the file. If the file does not exist, print an error message.
  • if the user selects changing directories, prompt the user for a directory or path to change to. Your script should try to change to the indicated directory, but does not need to check whether or not this attempt is successful. In other words, if the directory or path entered is valid, your script should change to that directory, but your script need not handle the case where the directory or path isn't valid. Your script should then display the contents of the current working directory, one page at a time.
  • if the user chooses to exit, your script should print a goodbye message and terminate.
  The script should run until the user selects the option to exit. For any other selection, after the selected option has been done, the menu should be redisplayed and the user should be able to select another option. (This is a variation on problem 10, p. 299 of the text.)

To hand in:

• Either turn in a print out of your script, or email me (wahls@psu.edu) the file containing your script. If you email me your script, I will email you your score and any comments on your script sometime after the due date. I will also save a copy of your script to prevent later disputes.
• Your script will be graded on correctness, style, readability and the clarity of messages printed for the user.

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