CS 114: UNIX Tools
Homework 1

Due Friday, March 2, 2:30 PM

Problem 1:
Send an e-mail to hollandm@cs.cornell.edu, FROM YOUR BABBAGE ACCOUNT, describing why you are taking CS114 and/or what specific topics you are hoping to see covered. The subject line must read: HW1 CS114

There is nothing additional to hand in for this problem.

Problem 2:
In this question, you are asked to browse a directory on babbage and find a set of files. Note that while you are welcome to explore "system" directories on babbage, such as those rooted at /bin, /usr, /var, /lib and so on, it is not considered appropriate to explore the directories of other users without their permission, even if the Unix permissions are set to allow it.

Within the ~cs114/P2 directory, find the files a.txt, b.txt, c.txt, and d.txt. For each file, record the path name of the file relative to ~cs114 (e.g., the pathname of the P2 directory relative to ~cs114 is ~cs114/P2).

Write down and hand in these path names for each file.

Problem 3:
In this question you will learn about some new commands and options using man pages.

• What does the "spell" command do? What does the -b flag do?
• What is the general format of the output of the "who" command? Show an example of using the who command where only the usernames are listed, and three usernames are listed per line.
• What four requirements are set on Unix passwords? (Hint: check the man page for passwd.)

Write down and hand in the answer to each of the questions above.

Problem 4:
In this question, you are asked to copy files from the cs114 home directory to your own account on babbage and perform some manipulations on these files.

While logged into babbage, do the following:

• Create a directory called 114HW1 in your home directory on babbage.
• Copy the three files in ~cs114/P4 to that directory.
• Rename cathedral.txt to bazaar.txt
• Make a subdirectory of 114HW1 called Humor and move whyVi.txt into that directory.
• Make a copy of hacker.txt called secret.txt - make sure that you can read and write this file, but not execute it, and that nobody else has any permissions on it.

Unless specified otherwise, you can make the permissions on these files and directories be whatever you like so long as:

• You do not give write permission to these files to anybody but yourself.
• The permissions are set up so that I, or another person, can check that you have completed this problem correctly. (Note: You may have a classmate help you check whether your permissons are set up correctly or not.)

There is nothing additional to hand in for this problem.