What is one way that hackers try to break Linux security?
2.
What's the best kind of password?
3.
What Linux command do you use to change the name or location of a file?
4.
Is Linux case-sensitive?
5.
Name the three most common Linux command shells.
6.
Why are shells better suited than C programs for some tasks?
7.
How do you terminate a process?
8.
How do you indicate the end-of-input when entering text from the keyboard?
9.
How do you terminate a shell?
10.
What term is given to the current location of a process?
11.
What attributes does every file have?
12.
What is the purpose of groups?
13.
How do permission flags relate to directories?
14.
Who may change the ownership of a file?
Exercises
1.
Describe how the mv command moves a file even though it doesn't touch the data blocks belonging to the file. [level: easy]
2.
Explain why a process may have only one current group. [level: medium]
3.
Even seemingly trivial inventions such as a flashing cursor and a scrolling window have been granted patents. Many software designers construct programs only to find that they have unintentionally re-invented someone else's patented invention. Do you think that patents are fair, and if not, can you think of a better mechanism to protect intellectual property? [level: medium]
4.
Design a file security mechanism that alleviates the need for the "set user ID" feature. [level: hard]
Project
1.
Use both vim and emacs to edit a file. Perform basic operations like adding text, deleting text, changing text on a line, and writing the file and exiting. Notice how in vim you're only in text input mode when you want to be, but in emacs you're in text input mode by default. Which feels more comfortable to you? If you have previous experience with a different screen-oriented editor, how do vim and emacs compare? [level: easy]
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2.
Set up two new groups (you may need assistance from a system administrator if you do not have access to the root password, or see "Substituting a User: su" on page 139). Experiment with the group-related utilities and explore the permissions system. [level: medium]
