Ch1 Advanced Shell Features Exam

Ch1 Advanced Shell Features Exam

1. Which of the following is a valid variable assignment?

   •  alpha-init=5
   •  MY VAR= “set to one”
   •  2=xyz
   •  APP_VAR=’zero’

2. Shell variables are case sensitive. True or False?

   • True
   • False

3. Which of the following is not a valid variable name?

   •  NEWVARIABLE
   •  VAR_1
   •  _LPIC
   •  2_VAR

4. A new environment variable can be exported and assigned a value with a single command. True or False?

   • True 
   • False

5. Which of the following is not a valid command for variable declaration?

   • export ENV_VAR=1 
   • newvar -x ENV_VAR=1 
   • typeset -x ENV_VAR=1 
   • declare -x ENV_VAR=1

6. The ___________ command is used to display the value of a specific variable.

   • set 
   • var 
   • echo 
   • value

7. Which command can be used to display both local and environment variables?

   • set 
   • declare -x
   • env 
   • export -p

8. Once a variable is declared, it cannot be deleted.

   True or False?

   • True 
   • False

9. Which of the following commands can be used to delete a variable?

   • rmvar 
   • declare 
   • set -r 
   • unset

10. The PATH variable directories are searched __________ when executing a command.

    • Left to right 
    • In no particular order 
    • Right to left 
    • Including only the first 256 characters

11. Which of the following is not a valid option for executing a command that is not in the directories listed in the PATH variable?

    • Add the directory containing the command to the PATH variable 
    • Copy the command to a directory listed in the PATH 
    • By typing the absolute or relative path to the command 
    • Rename the command and its directory

12. The command PATH=$PATH:/home/Alice does the following:

    • Creates a new PATH variable with only the /home/Alice directory as the value 
    • Replaces the existing directories in the PATH with the /home/Alice directory 
    • Appends the directory /home/Alice to the existing PATH variable 
    • Does nothing, because anything after the :is discarded

13. Consider the following value of PATH variable:/bin:/usr/local/sbin:/home/tom/bin:/home/tom/test

    Tom modifies the my_scr.sh script, which is stored in the directory /home/tom/bin then places a copy of my_scr.sh in /home/tom/test. Executing my_scr.sh will: 

    • Run the original version of the script in the /home/tom/bin directory 
    • Run the new version of the script placed in /home/tom/test 
    • Check the timestamp and run the latest version of my_scr.sh 
    • Not run at all, reports error

14. The ___________ command can be used to check if a command already exists.

    • check 
    • type 
    • ex 
    • command

15. Which of the following switches will include the full path in the prompt?

    • \H 
    • \w 
    • \e 
    • \W

16. Defining the PS1 variable in an initialization file will not make changes to the prompt persistent between logins.

    True or False?

    • True 
    • False

17. If the HISTIGNORE='ls*' command is placed in the ~/.bash_profile file, which of the following commands would not be placed in the history list?

    • cat 
    • history 
    • cd 
    • ls -la

18. Which of the following is not a purpose for creating an alias?

    • To create a short nickname for a long command or series of commands 
    • To make commands run faster 
    • To include a command option by default 
    • To create DOS-like commands

19. The command to remove an existing alias from the current shell is:

    • unalias 
    • rmalias 
    • alias -d 
    • unset alias

20. The best way to group multiple commands and pass arguments is to:

    • Concatenate them 
    • Use functions 
    • Create an alias 
    • Create an initialization file

21. A function is given 3 arguments as input. The third argument of a function is identified as:

    • $PATH 
    • $1 
    • $3 
    • $arg3

22. Changes in the __________ initialization file will affect all the users on the system.

    • Global 
    • Shell 
    • Local 
    • Network

23. Local initialization files, by default, are stored in which directory?

    • /etc 
    • /bin 
    • /usr 
    • User’s home directory

24. A login BASH shell executes which of the following additional files (compared to an interactive BASH shell)?

    • /etc/profile and either ~/.bash_profile or ~/.bash_login or ~/.profile 
    • ~/.bash_profile and ~/.bashrc 
    • /etc/profile and /etc/bashrc 
    • /etc/profile and ~/.bashrc

25. Administrators use the __________ file to create key environment variables and set key system values for every user.

    • /etc/bashrc 
    • /etc/profile 
    • .profile 
    • /etc/config

26. Sourcing is an effective way to test initialization file changes. Which of the following is used to source a file?

    • The touch command
    • The tilde ~ character 
    • None of the above 
    • Either the period . character or the source command

27. Which script is executed when you exit the shell?

    • ~/.bashrc 
    • ~/.bash_logout 
    • /etc/bashrc 
    • ~/.bash_profile

28. Typical BASH exit scripts are found in ~/.bash_logout and __________ files.

    • ~/.bash_profile 
    • /etc/bash_logout 
    • /etc/profile 
    • /etc/bashrc

29. Most of the Linux commands used by regular users can be found in which directory?

    • /sbin 
    • ~/bin 
    • /usr/bin 
    • /usr/local/sbin