The Essence of Unix and Linux - Practice Test Questions

THE ESSENCE OF UNIX AND LINUX TRUE/FALSE 1. In a peer-to-peer network, the system administrator secures all the information on the network by securing the server. ANS: F 2. You can switch from one shell to another by typing the shell’s name on the command line. ANS: T 3. UNIX/Linux are not case sensitive. ANS: F 4. The clear command has no options or arguments. ANS: T 5. Most shells keep a list of your recently used commands and allow you to recall a command without retyping it. ANS: T 6. The system administrator’s prompt is the $ (dollar sign). ANS: F 7. The less command scrolls only down, whereas more enables you to scroll down and up. ANS: F MULTIPLE CHOICE 1. UNIX/Linux are ____ systems, which let many people simultaneously access and share the resources of a server computer. a. superuser c. multitasking b. peer-to-peer d. multiuser ANS: D 2. UNIX and Linux are ____ systems, which allow one user to execute more than one program at a time. a. server-based c. multitasking b. peer-to-peer d. multiuser ANS: C 3. ____ is an Internet terminal emulation program. a. IP c. Telnet b. Emulab d. Terminal ANS: C 4. Currently, the ____ project, a joint effort of experts from industry, academia, and government, is working to standardize UNIX. a. POSIX c. ANSI b. BSD d. Ubuntu ANS: A 5. Stephen Bourne at AT&T Bell Labs developed the ____ shell as the first UNIX command processor. a. Bash c. C b. Bourne d. Korn ANS: B 6. Linux uses the freeware ____ shell as its default command interpreter. a. Bash c. C b. Bourne d. Korn ANS: A 7. The UNIX/Linux ____ command displays the system date, which the system administrator maintains. a. today c. system b. sysdate d. date ANS: D 8. You can use the ____ command to show the system calendar. a. clndr c. cal b. syscal d. calendar ANS: C 9. To determine information about who is logged in, you can use the ____ command. a. whatis c. whois b. who d. whoami ANS: B 10. In the Linux Bash shell, the ____ key combination moves the cursor to the previous letter. a. Ctrl+b c. Alt+l b. Alt+d d. Ctrl+a ANS: A 11. In the Linux Bash shell, the ____ key combination deletes the content of the command line from the current cursor position to the end of the command line. a. Ctrl+b c. Ctrl+k b. Alt+d d. Ctrl+a ANS: C 12. In the Linux Bash shell, the ____ key combination moves the cursor to the position just before the first character of the next word. a. Alt+l c. Ctrl+k b. Alt+d d. Ctrl+a ANS: A 13. In the Linux Bash shell, the ____ key combination deletes a word or consecutive characters. a. Ctrl+b c. Alt+l b. Alt+d d. Ctrl+a ANS: B 14. In the Linux Bash shell, the ____ key combination moves the cursor to the beginning of the command line. a. Ctrl+b c. Alt+l b. Alt+d d. Ctrl+a ANS: D 15. You can type more than one command on the command line by separating commands with a ____. a. vertical bar (|) c. semicolon (;) b. colon (:) d. dash (-) ANS: C 16. To log out of UNIX/Linux (Bourne, Korn, or Bash shells) you can enter exit on the command line or press ____. a. Ctrl+l c. Ctrl+x b. Ctrl+g d. Ctrl+d ANS: D 17. The ____ is the prompt symbol traditionally associated with ordinary users. a. dollar sign ($) c. tilde (~) b. pound sign (#) d. percent sign (%) ANS: A 18. Fedora, Red Hat Enterprise Linux, SUSE, and Knoppix, recognize up to ____ characters in your user name. a. 8 c. 32 b. 16 d. 64 ANS: C 19. A ____ is used to refer to the user’s home directory. a. dot (.) c. forward slash (/) b. dollar sign ($) d. tilde (~) ANS: D 20. You can change your password, if necessary, by using the ____ command, but you must know your current password to change it. a. pwd c. passwd b. chpwd d. password ANS: C 21. The head and tail commands, allow you to view the first few or last few lines of a file (____ lines by default). a. five b. ten c. fifteen d. twenty ANS: B 22. To append output to an existing file, you use ____. a .> b .>> ANS: B c .< d . << COMPLETION 1. A(n) ____________________ computer system, or PC, is usually a stand-alone machine, such as a desktop or laptop computer. ANS: personal 2. UNIX/Linux are ____________________ operating systems, which means that these systems can be used in a variety of computing environments. ANS: portable 3. ____________________ (FTP) is an Internet protocol used for sending files. ANS: File Transfer Protocol 4. A(n) ____________________ address is a set of four numbers (in the commonly used version 4) separated by periods, such as 172.16.1.61. ANS: IP IP (Internet Protocol) Internet Protocol Internet Procotol (IP) 5. ____________________ (SSH) was developed for UNIX/Linux systems to provide authentication security for TCP/IP applications, such as FTP and Telnet. ANS: Secure Shell 6. The system administrator is also called the ____________________, because the system administrator has unlimited permission to alter the system. ANS: superuser MATCHING Match each item with a statement below. a. terminal b. network c. shell d. mainframe e. domain f. g. h. i. host server root kernel 1. combines the convenience and familiarity of the personal computer with the ability to share files and other computer resources 2. provides multiuser access to network resources 3. large computer that has historically offered extensive processing, mass storage, and client access for industrial-strength computing 4. another name for server 5. device that has a monitor and keyboard, but no CPU 6. interface between the user and the operating system 7. base operating system 8. name that identifies a grouping of computer resources on a network 9. account that has complete access to a UNIX/Linux system 1. 2. 3. 4. 5. 6. 7. 8. 9. ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: B G D F A C I E H SHORT ANSWER 1. What is a peer-to-peer network? ANS: Peer-to-peer networks,which are often used on small networks, are more distributed than server-based networks. In a peer-to-peer configuration, each system on the network is both a server and a client. There is no central server to manage user accounts; instead, each peer offers its own shared resources and controls access to those resources, such as through a workgroup of designated members or through accounts created on that peer workstation. Data and applications reside on the individual systems in the network. Software upgrades and backup operations must be performed locally at each computer. Security, which is implemented on each computer, is not uniform. Each user of the network is, to some degree, responsible for administering his or her own system. Despite the disadvantages a peer-to-peer network presents to the system administrator, the individual users do not depend on a central server. If one computer in the network fails, the other systems continue to operate. 2. The concept of layered components that make up an operating system also originated with UNIX. Briefly describe this concept as it applies to UNIX/Linux systems. ANS: The concept of layered components that make up an operating system also originated with UNIX. Layers of software surround the computer system’s inner core to protect its vital hardware and software components and to manage the core system and its users. The layers of a UNIX system form a pyramid structure. At the bottom of the pyramid is the hardware. At the top are the users. The layers between them provide insulation, ensuring system security and user privacy. The kernel is the base operating system, and it interacts directly with the hardware, software services, application programs, and user-created scripts (which are files containing commands to execute). It is accessible only through Kernel mode, which is reserved for the system administrator. This prevents unauthorized commands from invading basic operating system code and hardware, resulting in actions that might hang or disrupt smooth operating system functions. User mode provides access to higher layers where all application software resides. This layered approach, and all other UNIX features,were designed by programmers for use in complex software development. 3. Describe the most common methods used to connect to or access a UNIX/Linux system. ANS: Some of the common ways to connect or to access a UNIX/Linux system are: - Through a Telnet or SSH connection to a remote computer, such as from another UNIX/Linux or a Windows-based operating system (Not all versions of Windows implement SSH, but you can obtain SSH from a third-party source, such as SSH Communications Security at www.ssh.com.) - Through client software on a UNIX/Linux client/server network - As a peer on a peer-to-peer, local area network in which each computer has the UNIX/Linux operating system installed - On a stand-alone PC that has the UNIX/Linux operating system installed - Through a dumb terminal connected to a communications port on a UNIX/Linux host 4. List the general steps used to access a UNIX/Linux host via Telnet. ANS: The general steps used to access a UNIX/Linux host via Telnet are: 1. Determine the remote host’s IP address or domain name. 2. Connect to your network or the Internet. 3. Start your Telnet program, and connect to the UNIX/Linux system. 4. Follow the instructions in your Telnet program to connect to a remote host. For example, telnet lunar.campus.edu 5. Provide a user name and password to log in to the remote UNIX/Linux computer. 5. What is the date command used for? ANS: The UNIX/Linux date command displays the system date, which the system administrator maintains. Because the date and time on a multiuser system are critical for applications, only the system administrator can change the date. For example, the Accounting Department might need to associate a date with a specific file used for reporting tax information, or the Publications Department might have to date stamp a document to ensure a specific copyright date. The date command has an option,-u,which displays the time in Greenwich Mean Time (GMT). 6. What is the who command used for? Why is this command important in a multiuser system? ANS: To determine information about who is logged in, use the who command. In a multiuser system, knowing who is logged in to the system is important for the administrator, so the administrator can periodically verify authorized users and levels of use. Knowing who is logged in is also valuable for ordinary users,who can use that information to judge how busy the system is at a given time or who might want to contact another user. 7. What is the man program? What argument(s) does it accept? ANS: For reference, UNIX/Linux include an online manual that contains all commands, including their options and arguments. The man program in UNIX/Linux displays this online manual, called the man pages, for command-line assistance. The man program usually accepts only one argument—the name of the command about which you want more information. The online manual shows the valid command formats that your system accepts. 8. Define command line history and describe its usage. ANS: Often, you find yourself entering the same command several times within a short period of time. Most shells keep a list of your recently used commands and allow you to recall a command without retyping it. You can access the command history with the up and down arrow keys. Pressing the up arrow key once recalls the most recently used command. Pressing the up arrow key twice recalls the second most recently used command. Each time you press the up arrow key, you recall an older command. Each time you press the down arrow key, you scroll forward in the command history. When you locate the command you want to execute, press Enter. This capability can save time and frustration when you need to enter the same or similar commands in one session. 9. What is the cat command and how is it used? ANS: The cat command gets its name from the word “concatenate”, which means “to link”. You can display multiple files by entering their file names after the cat command and separating them with spaces. UNIX/Linux then display the files’ contents in the order in which you entered them. 10. What is output redirection? How is it performed in UNIX/Linux? ANS: In UNIX/Linux, the greater-than sign (>) is called an output redirection operator. You can use this redirection operator to create a new file or overwrite an existing file by attaching it to a command that produces output. In effect, you redirect the output to a disk file instead of to the monitor. For example, if you type who > current_users and press Enter, this creates a file called current_users that contains the information from the who command. Redirecting output is useful in many circumstances. For example, when you monitor a system, you might redirect output to a file that you can examine later. Or, you might have a program or report-generating utility that manipulates data so that you can redirect the results to a file instead of to the screen. You learn about other redirection operators later in this book, but, for now, the > operator is a good starting point.