Linux Essentials Chapters 12,13,14 and 15

1.

1 point

Describe the effect of the following command, assuming it completes successfully:
# groupadd henry

It creates a new group called henry.

It imports group information from the file called henry.

It adds the group henry to the user’s list of groups.

It changes the user’s default group to henry.

2.

1 point

User accounts have lower UID numbers than do system accounts.

True

False

3.

1 point

What is the purpose of conditional expressions in shell scripts?

They enable the script to take different actions in response to variable data.

They prevent scripts from executing if license conditions aren’t met.

They cause scripts to run only at specified times of day.

They enable scripts to learn in a manner reminiscent of Pavlovian conditioning.

4.

1 point

Linux stores information on its groups in the /etc/groups file.

True

False

5.

1 point

What command would you type (as root) to change the ownership of somefile.txt from ralph to tony?

chmod tony somefile.txt

chown somefile.txt tony

chmod somefile.txt tony

chown tony somefile.txt

6.

1 point

To create a system account, you must pass the ____ option to groupadd.

7.

1 point

User accounts have higher UID numbers than do system accounts.

True

False

8.

1 point

The file that associates usernames with UID numbers in Linux is _______________.
(Provide the complete path to the file.)

9.

1 point

You want to change the username of a user from elnino to torres, without
altering anything else about the account. To do so, you would type __________.

10.

1 point

What would a Linux system administrator type to remove the nemo account and
its home directory?

userdel -r nemo

userdel -f nemo

rm /home/nemo

userdel nemo

11.

1 point

You want to run the command iptables -L as root, but you’re logged in as
an ordinary user. Which of the following commands will do the job, assuming the
system is configured to give you root access via the appropriate command?

root iptables -L

admin iptables -L

sudo iptables -L

passwd iptables -L

12.

1 point

Only root may change a file’s ownership with chown.

True

False

13.

1 point

Unvalid looping statements in Bash include for, while, and until.

True

False

14.

1 point

What command can you use to display prompts for a user in a shell script?

15.

1 point

You want to create an account for a new user, using the username theowalcott and
giving the user a UID of 1926. The command to do this is useradd ________.

16.

1 point

What symbolic representation can you pass to chmod to give all users execute
access to a file, without affecting other permissions?

17.

1 point

A user types myscript laser.txt to run a script called
myscript. Within myscript, the $0 variable holds the value laser.txt.-

True

False

18.

1 point

Which of the following commands can you use to change a file’s group?

chown

ls

groupadd

groupmod

chmod

19.

1 point

You’ve written a simple shell script that does nothing but launch programs.
In order to ensure that the script works with most user shells, what should its first line read?

20.

1 point

Linux stores information on its groups in the /etc/group file.

True

False

21.

1 point

What three-character symbolic string represents read and execute permission
but no write permission?

22.

1 point

Command-line users should normally use usermod to change their
passwords.

True

False

23.

1 point

After deleting an account, files formerly owned by the deleted
account may remain on the computer.

True

False

24.

1 point

A file with permissions of 755 can be read by any user on the
computer, assuming all users can read the directory in which it resides.

True

False

25.

1 point

What option causes chown to change ownership on an entire directory tree?

26.

1 point

What Bash scripting command can you use to control the program flow based on
a variable that can take many values (such as all the letters of the alphabet)?

27.

1 point

whoiam provides more information than id.

True

False

28.

1 point

Of the following, which is the best password?

LinusTorvalds

password

uB2op%4q****************

peanutbuttersandwich

29.

1 point

Describe the effect of the following short script, cp1, if it’s called as cp1 big.c
big.cc:
#!/bin/bash
cp $2 $1

The script’s first line is invalid, so it won’t work.

It compiles the C program big.c and calls the result big.cc.

It copies the contents of big.cc to big.c, eliminating the old big.c.

The script’s first line is invalid, so it won’t work.

30.

1 point

Valid looping statements in Bash include for, while, and until.

True

False

31.

1 point

The following script doesn't launch three simultaneous instances of the
terminal program.

#!/bin/bash
terminal
terminal
terminal

True

False

32.

1 point

What type of information will you find in /etc/passwd for ordinary user
accounts? (Select all that apply.)

The path to the account’s default GUI desktop environment

The path to the account’s home directory

A complete listing of every group to which the user belongs

The path to the account’s default text-mode shell

A user ID (UID) number

33.

1 point

UIDs below 500 or 1,000 (depending on the distribution) are reserved for use
by __________ accounts.

34.

1 point

As a general rule, you should employ extra care when running
programs as root.

True

False

35.

1 point

The following script launches three simultaneous instances of the
terminal program.

#!/bin/bash
terminal
terminal
terminal

True

False

36.

1 point

whoami provides more information than id.

True

False

37.

1 point

To learn who is currently logged into the computer and what programs they’re
currently running, you can type _____.

38.

1 point

Only root or a file owner may change the permissions on a file.

True

False

39.

1 point

After using a text editor to create a shell script, what step should you take before
trying to use the script by typing its name?

Run a virus checker on the script to be sure it contains no bugs.

Copy the script to the /usr/bin/scripts directory.

Set one or more executable bits using chmod.

Run a virus checker on the script to be sure it contains no viruses.

Compile the script by typing bash scriptname, where scriptname is the script’s name.

40.

1 point

Typing ls -ld wonderjaye reveals a symbolic file mode of drwxr-xr-x.
Which of the following are true? (Select all that apply.)

wonderjaye is a directory

wonderjaye may be read by all users of the system

wonderjaye is an excutable program

wonderjaye is a symbolic link

wonderjaye may be written by any member of the file's group

41.

1 point

What is the purpose of the system account with a UID of 0?

Nothing; UID 0 is left intentionally undefined.

It’s the account for the first ordinary user.

It’s a low-privilege account that’s used as a default by some servers.

It’s the system administration account.

42.

1 point

Only root may use the chmod command.

True

False