Chapter 15: Working With The Command Line Interface - CompTIA A+ Certification All-in-One Exam Guide, Tenth Edition

Question 1

List three reasons the command-line is popular.

Answer 1

1. If you know what you are doing, you can do most jobs more quickly using the command line than with a graphical user interface.
2. The command-line interface doesn’t take much operating system firepower, so it’s a natural choice for jobs where you don’t need a full-blown GUI for an OS.
3. Text commands are easily added to scripts, enabling you to perform complex tasks automatically.

Question 2

Define a prompt

Answer 2

A character or message provided by an operating system or program to indicate it is ready to accept input.

Question 3

Define a shell.

Answer 3

Tool that interprets command-line input, also known as a command-line interpreter.

Question 4

What is a command?

Answer 4

A request, typed from a terminal or embedded in a file, to perform an operation or to execute a particular program.

Question 5

What is bash?

Answer 5

Default command shell on macOS and most Linux distros.

Question 6

How do access the CLI?

Answer 6

You can access the CLI through the Start menu or the Start screen’s Search bar. Type cmd from the Start screen then press enter when the Search option appears with the full command.

Question 7

How do you close the CLI?

Answer 7

You can either click the Close box in the upper-right corner of the screen or type “exit” and press ENTER.

Question 8

When will you be prompted “Windows needs your permission to continue.”

Answer 8

Whenever you attempt to enter a Windows command prompt command that requires elevated or administrative privileges.

You can manually run a command with elevated privileges by right-clicking on a command prompt shortcut and selecting “Run as an administrator” or if Windows prompts for an admin password or credentials, enter whatever is needed.

Question 9

How do you create a shortcut to run the CLI with admin privileges?

Answer 9

1. Right-click desktop and create a new shortcut.
2. Enter cmd as the location and the name of the shortcut.
3. Right-click the shortcut, select properties > Advanced > check “Run as Administrator.
4. Click OK.

Question 10

MacOS and Linux are based off of what operating system?

Answer 10

UNIX

Question 11

What is Terminal?

Answer 11

A command-line tool available in macOS and various Linux distros.

Question 12

What is the name of the CLI in Ubuntu Linux?

Answer 12

Terminal.

Just like in macOS.

Question 13

Name two other CLI emulators for Linux distros.

Answer 13

Konsole Terminal

GNOME Terminal

Question 14

How do you launch the Terminal in macOS?

Answer 14

1. Launch the Terminal app from the Utilities folder (located in the Applications folder).
2. Activate Spotlight (COMMAND-SPACEBAR), type terminal, and press ENTER.

Question 15

Why is Spotlight so great on macOS?

Answer 15

It is a great search tool because it indexes your drives, not just your file names, but content.

This means you can search for specific files, but also apps, email messages, music, contacts and even flight information!

Question 16

How do you open a terminal emulator in Linux (generally)?

Answer 16

Every Linux distro has some form of finder or search function on the desktop that works similarly to the search tools in macOS or Windows. Find this tool and type terminal and press ENTER to start the program. This will bring up the terminal window.

Question 17

Define Linux command “su.”

Answer 17

Older Linux command for gaining root access.

Question 18

Define Linux command “sudo.”

Answer 18

Linux command for gaining root access.

Question 19

How do you run the CLI with advanced privileges, called “super user” or “root privileges.”

Answer 19

Whenever you need to run a command as root, type sudo followed by the desired command. (the system will prompt for a password and then run the command).

If the system doesn’t have sudo, it should have su. You will typically type su at the prompt and press ENTER; you will then be prompted for the root password. (When you have successfully entered the password, the prompt will change (usually changing the character at the end from a $ to a #) and every command you enter from then on will be executed as root.

Question 20

How do you stop working as root?

Answer 20

Type “exit” and press ENTER while you are working in root. You will then return to the normal prompt.

Question 21

Many Linux systems disable the root account for safety, rendering the ___ command inoperable. The ___ command enables users to do root things without having their root password.

Answer 21

1. Su

2. Sudo

Question 22

Define the working directory.

Answer 22

The current directory used by command-line commands unless they explicitly specify a target file or directory. The prompt usually indicates the working directory.

Question 23

The command prompt focuses on a specific folder, the working directory, usually indicated by the prompt. What is an example of focus in Windows?

If you a prompt that looks like this line, you know that the focus is on the root directory of the C: drive.

Answer 23

C: >

Question 24

How is the working directory naming protocol different in macOS and Linux as opposed to Windows? Name three ways.

Answer 24

1. macOS and Linux don’t use the lettering concepts of drives like windows, as all forms of storage are mounted simply as folders.
2. Linux prompts show the currently logged-on user and system as well as the current directory.
3. MacOS and Linux use a forward slash (/) instead of a backslash ().

Question 25

How would the prompt display user mike is on the “server” system and is on the home directory in macOS or Linux?

Answer 25

mike@server:/home$

Question 26

How would the prompt look in Windows, if the focus was on the \Diploma\APLUS\ folder of the C: drive?

Answer 26

C:\Diploma\APLUS>

Question 27

The trick of using a command line is first to focus the prompt on the ____ and ____ where you want to work.

Answer 27

Drive, folder

Question 28

How do you close the Terminal?

Answer 28

At the prompt, type exit and press ENTER.

Question 29

The command line requires _________. That means you need to type commands, file names, and switches accurately. Otherwise, you get errors or no results at all.

Answer 29

Precision.

Question 30

Define file format.

Answer 30

How information is encoded in a file. Two primary types are binary (pictures) and ASCII (text), but within those are many formats, such as BMP and GIF for pictures. Commonly represented by a suffix (the file extension) at the end of the file name; for example, .txt for a text file or .exe for an executable.

Question 31

Define file extension.

Answer 31

Two, three, four, five, or more letters that follow a file name and identify the type of the file (file format). Common file extensions are .zip, .exe, .doc, .java, and .xhtml.

Question 32

In Windows, Hard drive partitions usually start with the letter _____.

Answer 32

C:

Question 33

Optical drives by default follow what lettering protocol?

Answer 33

The next available drive letter after the last hard drive partition.

Question 34

How else can you mount a hard drive in Windows?

Answer 34

As a volume in another drive.

Question 35

MacOS and Linux don’t use drive _______. Instead, the boot partition is defined as the __________, shown as a slash: /.

Answer 35

Lettering; root drive.

Question 36

All other storage on macOS or Linux distros—partitions, optical discs, thumb drives, etc.—must go through a process called ____ to enable the OS to treat them as folders. These folders are ____ to a single folder off the _____ called the ____ or _____ in Linux and _______ in macOS.

Answer 36

Mounting; mounted; root drive; /mount; /media; /Volumes.

Question 37

All operating systems use a _______ ________ ______ to organize the contents of these drives.

Answer 37

hierarchical directory tree

Question 38

All files are put into groups called folders. But many techs refer to them by the interchangeable term _____.

Answer 38

Directory

Question 39

Define root directory.

Answer 39

Directory that contains all other directories.

Question 40

Define sub folder.

Answer 40

A folder located inside another folder.

Question 41

Any file not in a folder within the tree—that is, any file in the folder at the root of the directory tree—is said to be in the _______.

Answer 41

Root directory.

Question 42

Can two files exist with the same name on one PC?

Answer 42

Yes, but two files with the same name can not exist in the same folder.

Question 43

Can two subfolders on one PC have the same name?

Answer 43

Yes, but two subfolders within the same folder cannot have the same name.

Question 44

Define path:

Answer 44

Route the OS must follow to find an executable program stored in a subfolder.

Question 45

How would you write the path for the test2.txt file located in the System subdirectory of the root directory Test within the C: drive?

Answer 45

C:\Test\System\test2.txt.

Question 46

C:\Program Files C:\Users\mike\Desktop C:\FRUSCH3\Clear D:\ Are all examples of valid Windows ______.

Answer 46

Paths.

Question 47

Folder names in Linux and macOS use a _____ as opposed to Windows when separating folder names.

Answer 47

Forward slash /

Question 48

Which of the three main operating systems uses case sensitivity in paths?

Answer 48

Linux.

Question 49

Which OS could have a folder with two files named Mike and mike?

Answer 49

Linux

Question 50

/usr/local/bin /Applications/Utilities /home/mike/Desktop / Are all valid path names in which OS?

Answer 50

Linux and macOS.

Question 51

Within Linux and macOS, generally, your default prompt is pointing at the /home//folder. By default, these two OS do not show that path, but instead show a _____.

Answer 51

Tilde, ~

Question 52

Mike@server:~$ points to which path generally?

Answer 52

Mike@server:/home/mike

Question 53

Which command can you use in Linux and macOS to check your current path?

Answer 53

pwd pwd shows you the working directory. The output includes the full path.

Question 54

What are the eleven disallowed Windows characters for files and folders?

Answer 54

*”/|[]:;|=,

Question 55

What is the only disallowed character in macOS and Linux file naming?

Answer 55

Forward slash /

Question 56

Files aren’t required to have _______, but in most cases the OS won’t know the file association type without one.

Answer 56

Extension.

Question 57

Exam tip!

Answer 57

Questions on the CompTIA A+ exam will couch questions in the forms of scenarios. “Given the scenario, which OS tool/command would be appropriate?”

Question 58

Define a switch.

Answer 58

Within networking, it is a device that filters and forwards traffic based on some criteria. A bridge and a router are both examples of switches. In a command line interface, a switch is a function that modifies the behavior of a command.

Question 59

Another name for a switch (in the CLI).

Answer 59

Option.

Question 60

The proper way to write a command is called its _____.

Answer 60

Syntax.

Question 61

What are two keys with commands?

Answer 61

You can’t spell anything incorrectly or use a \ when syntax calls for a /.

Question 62

The command line is almost completely ______. Meaning, you have to learn the correct ______ for each command.

Answer 62

Inflexible; syntax.

Question 63

What are two ways to generally write command syntax?

Answer 63

[command] [target (if any)] [switches] Or [command] [switches] [target (if any)]

Question 64

If you want to find out the syntax and switches used by a particular command, in Windows type the command followed by ____ to get help

Answer 64

/? For example: [command name] /?

Question 65

In macOS or Linux, type the command ____ (manual) followed by the command you’re interested in:

Answer 65

man [command name]

Question 66

How do you exit the manual? That is the help screen in CLI for identifying syntax and switches for commands in Linux and macOS.

Answer 66

Press the q key to quit back to the prompt.

Question 67

What is the system checklist for troubleshooting?

Answer 67

1. Check all physical connections. 2. Check hardware integrity. 3. Restart. 4. Check event viewers/logs. 5. Uninstall and reinstall affected feature.

Question 68

What are the steps for analyzing symptoms?

Answer 68

1. What controls this system feature or device? 2. Does this only occur when an application is running? 3. What is happening when this problem occurs? 4. Has this ever happened before? If so, how frequently? 5. Has anything been installed recently - hardware or software? 6. What are the system specifications for this device or application? Does this system meet them?

Question 69

CompTIA’s Troubleshooting Process (6 steps)

Answer 69

1. Identify the problem. 2. Establish a theory of probable cause. 3. Test the theory to determine cause. 4. Establish a plan of action to resolve the problem and implement the solution. 5. Verify full system functionality and, if applicable, implement preventative measures. 6. Document findings, actions and outcomes.

Question 70

What causes the Blue Screen of Death? What is it?

Answer 70

``` Cause of kernel process error. kernel service device drivers Malfunctioning hardware kernel level root kits. ``` Windows Stop Error Presents diagnostic information.

Question 71

Since ________, by default Windows restarts immediately after a Blue Screen of Death.

Answer 71

Vista.