Chapter 2 Getting Started

The following message is displayed when you attempt to log in with an incorrect username or and incorrect password. This message does not indicate whether your username, your password, or both are invalid. Why does it not tell you this information.

By hiding user information, this avoids unauthorized people from taking user name and passwords. If other people can get the information, then they can access to the system. So, this is why it does not reveal the information.

Briefly, what information does the --help option display for the tar utility? How would you display this information one screen at a time.

Displays information about the utility.

What would you do if you could not log in?

Its possible that the root account is disabled by default and you need to log in as yourself and then gain root privileges. Sometimes when a filesystem critical to the log in process is full, it seems like you've logged in successfully but the login reappears and you have to boot the system into rescue/recovery mode. You can also make sure that you're logging into the correct machine.

Is fido an acceptable password? Give several reasons why or why not.

No, there aren't enough characters, It's something you can find in the dictionary, there are no numbers or punctuation and it's something recognizable and relevant.

How would you repeat the second preceding command line, edit it, and then execute it?

Press the UP ARROW twice, delete and type to edit, repeat the command using !!.

How many man pages are in the Devices subsection of the system manual?

There are ten different subsections. 1. User Commands 2. System Calls 3. Subroutines 4. Devices 5. File Formats 6. Games 7. Miscellaneous 8. System Administration 9. Kernel 10. New

Try to change your password to dog. What happens? Now change it to a more secure password. What makes that password relatively secure?

To change a password on behalf of a user, first sign on or "su" to the "root" account. Then type, ``passwd user'' (where user is the username for the password you are changing). The system will prompt you to enter a password. Passwords do not echo to the screen when you enter them.

How would you change your login shell to tcsh without using root privileges?

Use Chsh

How would you display a list of utilities that compress files?

You type: info coreutils. h or ? to list info commands. SPACE to scroll through the display. m followed by the name of the menu you want to display or a SPACE to display a list of menus. q or control-c to quit. Pinfo

How would you display the man page for shadow in section 5 of the system manual?

You would type man 5 shadow to get to section 5 of the manual for shadow. If you were just going to look at the man for shadow you would type man shadow.

The example on page 35 shows that man pages for passwd appear in section 1 and 5 of the system manual. Explain how you can use man to determine which sections of the system manual contain a manual page with a given name.

man -a passwd to view all man pages for passwd.

Give three examples of poor password choices. What is wrong with each? Include one that is too short. Give the error message the system displays.

picklez, Should contain at least two characters, or one digit or punctuation character Natalie10, should not be any recognizable name place or person, or username bugle, only 5 characters and you need 6, shouldn't be in the dictionary BAD PASSWORD: it is too short.

How would you find out which Linux utilities create and work with archive files?

probably info