010-160 Linux Essentials Certificate Exam - version 1.6 Questions and Answers

The commands man ls and info ls are used to get information on the proper use of ls. The man command displays the manual page for a given command, which contains a description, synopsis, options, examples, and other details. The info command displays the info page for a given command, which is similar to the manual page but may have more information and hyperlinks. The option ls, usage ls, and manual ls commands are not valid commands in Linux and will result in an error message. References:

• Linux Essentials Exam Objectives, Version 1.6, Topic 103.1, Weight 2
• Linux Essentials Certification Guide, Chapter 3, Page 51-52
• Ls Command in Linux (List Files and Directories) | Linuxize

 Web browser cookies are small pieces of data that are stored by a website on a user’s browser. They are used to remember information about the user, such as preferences, login details, shopping cart items, etc. Cookies can also be used to identify and track users across different websites, which can have implications for privacy and security. For example, cookies can be used to show targeted ads based on the user’s browsing history, or to collect personal information without the user’s consent. Cookies are not inherently dangerous, but they can pose some risks if they are misused or compromised by malicious actors. References:

• Linux Essentials - Linux Professional Institute (LPI), section 1.4.2
• 1.4 Lesson 1 - Linux Professional Institute Certification Programs, slide 18

A Linux distribution is a collection of software that is based on the Linux kernel and can be installed on a computer or a device to create a functional operating system. A Linux distribution typically includes the Linux kernel, a set of system utilities and libraries, a graphical user interface (GUI), a package manager, and various applications and services. A Linux distribution may also include additional software or features that are specific to the distribution’s goals, target audience, or philosophy. For example, some Linux distributions are designed for desktop users, while others are optimized for servers, embedded systems, or security. Some Linux distributions are based on other Linux distributions, while others are developed independently. Some Linux distributions are free and open source, while others are proprietary or commercial. Some Linux distributions are popular and widely used, while others are niche or experimental. Some examples of Linux distributions are Ubuntu, Fedora, Debian, Mint, Arch, and Red Hat. References:

• Linux Essentials Topic 101: System Architecture, section 101.1: Determine and configure hardware settings.
• Linux Essentials Topic 102: Linux Installation and Package Management, section 102.1: Design hard disk layout.
• Linux Essentials Topic 103: GNU and Unix Commands, section 103.1: Work on the command line.
• Linux Essentials Topic 104: The Linux Operating System, section 104.1: Boot the system.
• Linux Essentials Topic 105: The Power of the Command Line, section 105.1: Use text streams and filters.
• Linux Essentials Topic 106: Security and File Permissions, section 106.3: Modify file and directory permissions.
• What is a Linux distribution? - Linux.com
• Linux distribution - Wikipedia
• Best Linux Distributions For Everyone in 2023 - It’s FOSS

 CentOS is a Linux distribution that is derived from Red Hat Enterprise Linux (RHEL). CentOS stands for Community Enterprise Operating System and it aims to provide a free, enterprise-class, community-supported computing platform that is functionally compatible with RHEL. CentOS is one of the most popular Linux distributions for servers and cloud computing. Raspbian, openSUSE, Debian and Ubuntu are other Linux distributions that are not derived from RHEL, but have their own origins and development histories. Raspbian is based on Debian and optimized for the Raspberry Pi. openSUSE is a community project sponsored by SUSE Linux and other companies. Debian is one of the oldest and most influential Linux distributions, and Ubuntu is derived from Debian and sponsored by Canonical Ltd. References:

• Linux Essentials - Linux Professional Institute (LPI) 1
• Linux Essentials Version 1.6 Update - Linux Professional Institute (LPI) 2
• Free LPI 010-160 Questions - Pass LPI 010-160 - Pass4Success 3
• LPI Linux Essentials Study Guide: Exam 010 v1.6, 3rd Edition 4

The keyword for is used in a shell script to begin a loop that iterates over a list of items or a range of numbers. The syntax of the for loop is as follows:

for in do done

The variable is assigned to each element of the in turn, and the are executed for each iteration. The can be a sequence of words, numbers, filenames, or other values. If the is omitted, the for loop will iterate over the positional parameters ($1, $2, …). The do and done keywords mark the beginning and the end of the loop body, respectively. The for loop is one of the three types of loops in shell scripting, along with the while and until loops. References: 1: Looping Statements |Shell Script - GeeksforGeeks 1 2: unix - Shell script "for" loop syntax - Stack Overflow 2 3: For Loop Shell Scripting - javatpoint 3

 Ubuntu Linux LTS and Red Hat Enterprise Linux are two Linux distributions that meet the requirements of hosting services for a period of several years and receiving important security updates from their Linux distribution. LTS stands for Long Term Support, which means that these versions of Ubuntu Linux are supported by Canonical, the company behind Ubuntu, for five years with security patches, bug fixes, and software updates1. Red Hat Enterprise Linux is a commercial Linux distribution that offers a stable and secure platform for enterprise applications, with a 10-year life cycle and regular security updates from Red Hat, the company behind RHEL2. Fedora Linux, Debian GNU/Linux Unstable, and Ubuntu Linux non-LTS are not suitable for the requirements, because they have shorter support cycles and are more focused on providing the latest features and software versions, rather than stability and security. Fedora Linux releases a new version every six months and each version is supported for 13 months3. Debian GNU/Linux Unstable is the development branch of Debian, which is constantly updated with new packages and changes, but is not intended for production use4. Ubuntu Linux non-LTS releases a new version every six months and each version is supported for nine months1. References:

• Ubuntu release cycle | Ubuntu
• Red Hat Enterprise Linux Life Cycle - Red Hat Customer Portal
• Fedora Release Life Cycle - Fedora Project Wiki
• Debian Unstable - Debian Wiki

A process ID on Linux is a unique integer value that identifies a running process. The process ID can range from 0 to a maximum limit, which is usually 32768 or higher, depending on the system configuration. The process ID of 0 is reserved for the kernel’s idle task, and the process ID of 1 is reserved for the init system, which is the first process launched by the kernel. The process IDs are assigned sequentially to new processes, and are recycled when a process terminates. Therefore, the only valid value for a process ID among the given options is 21398, which is an integer within the possible range. The other values are not valid process IDs because they are either strings, hexadecimal numbers, or file paths, which do not match the format of a process ID on Linux. References:

• Linux Essentials - Linux Professional Institute (LPI)
• How Are Linux PIDs Generated? | Baeldung on Linux

 The correct command to copy the contents of the directory /etc/, including all sub-directories, to /root/ is cp -r /etc/* /root. This command uses the cp command, which stands for copy, and is used to copy files and directories on Linux and Unix systems. The command also uses the following options and arguments123:

• The -r option, which stands for recursive, and tells cp to copy all files and sub-directories of the source directory. Alternatively, the -R option can be used, which has the same effect as -r.
• The /etc/* argument, which specifies the source directory and all its contents. The asterisk (*) is a wildcard character that matches any file or directory name. This argument tells cp to copy everything inside the /etc/ directory, but not the directory itself.
• The /root argument, which specifies the destination directory. This argument tells cp to copy the source files and sub-directories to the /root/ directory.

The other options are incorrect because they use different commands or syntax that do not copy the contents of the directory /etc/, including all sub-directories, to /root/. For example:

• Option A uses the copy command, which is not a valid Linux command. The correct command is cp.
• Option C uses the -v option, which stands for verbose, and tells cp to print verbose output. This option does not affect the copying process, but only the output. It also does not include the -r or -R option, which is necessary to copy the sub-directories.
• Option D uses the rcp command, which stands for remote copy, and is used to copy files between different hosts on a network. This command is not relevant for copying files on the same host.
• Option E uses the -R option, which is correct, but also uses the . argument, which is incorrect. The dot (.) is a special character that matches any single character. This argument tells cp to copy only the files and directories that have a dot in their name, which may exclude some files and directories that do not have a dot.

References: 1: Cp Command in Linux (Copy Files) | Linuxize 2: cp command in Linux with examples - GeeksforGeeks 3: How to Copy Files and Directories in the Linux Terminal

RPM stands for RPM Package Manager (formerly known as Red Hat Package Manager), which is a powerful, command-line package management tool developed for the Red Hat operating system. It is now used as a core component in many Linux distributions such as CentOS, Fedora, Oracle Linux, openSUSE and Mageia1. RPM can install, uninstall,and query individual software packages, but it cannot manage dependency resolution like YUM2. YUM is another package management tool that is based on RPM and can handle dependencies automatically. YUM is the primary package management tool for installing, updating, removing, and managing software packages in Red Hat Enterprise Linux2. Therefore, the correct answer is B. rpm, as it is the underlying package management tool used in Red Hat-based Linux systems. References:

• Linux package management with YUM and RPM | Enable Sysadmin
• Chapter 13. Package Management Tool Red Hat Enterprise Linux 5 | Red Hat Customer Portal
• Difference Between YUM and RPM | 2DayGeek

 A shell script is a file that contains a series of commands that can be executed by a shell interpreter. To execute a shell script, there are two main methods:

• Method 1: Specify the path to the script file. This method requires that the script file has the execute permission, which can be granted by using the chmod command. The script file also needs to have a shebang line at the beginning, which indicates which interpreter to use for the script. For example, #!/bin/bash means to use the bash interpreter. To execute the script using this method, you can type the absolute path or the relative path to the script file. If you are in the same directory as the script file, you can use the ./ prefix to indicate the current directory. For example, ./test.sh will execute the test.sh script in the current directory.
• Method 2: Pass the script file as an argument to the interpreter. This method does not require the execute permission or the shebang line for the script file. You can simply use the name of the interpreter followed by the script file name as an argument. For example, bash test.sh will execute the test.sh script using the bash interpreter.

Therefore, the correct answers are D and E. A. run test.sh is incorrect because run is not a valid command in Linux. B. ${test.sh} is incorrect because this syntax is used for variable expansion, not for executing a script. C. cmd ./test.sh is incorrect because cmd is not a valid command in Linux. References:

• Linux Essentials Topic 105: The Power of the Command Line, section 105.3: Basic shell scripting.
• How to Run a Shell Script in Linux [Essentials Explained] - It’s FOSS
• How To Execute a Command with a Shell Script in Linux | DigitalOcean
• How To Run the .sh File Shell Script In Linux / UNIX

The command pwd stands for “print working directory”. It will print the absolute path of the current working directory to the terminal. For example, if we are currently in the /home/user/directory, it will print out that exact path1. The pwd command is useful for finding out where we are in the file system hierarchy and for verifying the location of files and directories2.

The other options are not commands that show the absolute path to the current working directory. The who command shows the users who are currently logged in to the system3. The cd … command changes the current working directory to the parent directory of the current one2. The ls -l command lists the files and directories in the current working directory in a long format, which shows the permissions, ownership, size, date, and name of each file and directory2. The cd ~/home command changes the current working directory to the /home directory under the user’s home directory, which may or may not exist2. References:

• Linux Essentials Exam Objectives, Version 1.6, Topic 103.1, Weight 2
• Linux Essentials Certification Guide, Chapter 3, Page 51-52
• How to Get the current directory in Linux - howtouselinux
• How To Find The Absolute Path Of A File Or Directory In Linux - systranbox

 In an Infrastructure as a Service (IaaS) cloud, the provider offers virtualized computing resources such as servers, storage, and network over the internet. The user can provision and manage these resources according to their needs. One of the common ways to provision a new Linux computing instance in an IaaS cloud is to use a pre-prepared image of a Linux distribution provided by the cloud hosting organization. An image is a snapshot of a virtual machine that contains the operating system and other software components. The user can choose from a variety of images that suit their requirements and launch a new instance from the image. This way, the user does not have to install and configure the Linux operating system from scratch, which saves time and effort. Some examples of cloud hosting organizations that provide pre-prepared images of popular Linux distributions are Amazon Web Services (AWS), Microsoft Azure, Google Cloud Platform (GCP), and DigitalOcean. References: Linux Essentials - Topic 108: Cloud Computing and Linux Essentials - Topic 108: Cloud Computing - Exam Objectives

The ls command is used to list the files and directories in a given path. By default, the ls command displays only the file names, without any additional information. However, the ls command can also take various options to modify its output. For example, the -l option tells ls to display the long format, which includes the file permissions, owner, group, size, date, and name. The -h option tells ls to display the file sizes in a human-readable format, such as KB, MB, GB, etc. The -a option tells ls to display all files, including thehidden ones that start with a dot (.). The -n option tells ls to display the numeric user ID and group ID instead of the user name and group name. Therefore, the only option that does not add any additional information to the file names is the -a option. The command ls -a will display all the file names in the current directory, including the hidden ones, but nothing else. References:

• Linux Essentials - Linux Professional Institute (LPI), section 2.1.1
• 2.1 Lesson 1 - Linux Professional Institute Certification Programs, slide 6.

The command that displays manual pages for Linux commands is the man command. The man command is used to display the manual pages for a given command or topic. For example, to view the manual page for the ls command, you can type:

man ls

This will open the manual page for the ls command in a pager, which allows you to scroll and search through the text. You can also specify the section number of the manual page if there are multiple pages with the same name. For example, to view the manual page for the passwd command in section 1, you can type:

man 1 passwd

The man command is one of the most useful and important commands for learning and using Linux. It provides detailed information about the syntax, options, arguments, examples, and other aspects of a command or topic. You can also use the --help option to get a brief summary of the usage and options of a command. For example, to get a quick help for the man command, you can type:

man --help

To learn more about the man command and how to use it effectively, you can refer to the following resources:

• Linux Essentials Exam Objectives, Version 1.6, Topic 103.1, Weight 2
• Linux Essentials Certification Guide, Chapter 3, Page 51-52
• How to Access Manual Pages for Linux Commands - Linux Tutorials - Learn Linux Configuration
• How to Easily Read a Linux Man Page - Make Tech Easier

A vector graphics editor is a software program that allows users to create and edit vector graphics, which are images composed of mathematical curves and shapes. Vector graphics are scalable, meaning they can be resized without losing quality or clarity. Python, NGINX, Samba, and MySQL are not vector graphics editors, but rather other types of software. Python is a programming language, NGINX is a web server, Samba is a file and print server, and MySQL is a database management system. Inkscape is a free and open source vector graphics editor that supports the SVG (Scalable Vector Graphics) format, as well as other formats. Inkscape can be used to create logos, icons, diagrams, illustrations, and other graphics. Inkscape is one of the applications covered in the Linux Essentials certification program from the Linux Professional Institute (LPI). References:

• Linux Essentials - Linux Professional Institute (LPI)
• Draw Freely | Inkscape

The /proc/ directory is a virtual file system that contains information about the system and the processes running on it. It is not a conventional file system that stores files on a disk, but rather a dynamic view of the kernel’s data structures. One of the features of the /proc/ directory is that it contains one subdirectory for each process running on the system, which is named after the process ID (PID). For example, the subdirectory /proc/1/ contains information about the process with PID 1, which is usually the init process. The process subdirectories contain various files that provide information about the process, such as its status, memory usage, open files, environment variables, command line arguments, and more. The /proc/ directory also contains a symbolic link called ‘self’, whichpoints to the process that is accessing the /proc/ file system. Therefore, the correct answer is D. One directory per running process.

The other options are incorrect because:

• A. One directory per installed program. This is not true, as the /proc/ directory does not contain information about installed programs, but only about running processes. Installed programs are usually stored in other directories, such as /bin/, /usr/bin/, /opt/, etc.
• B. One device file per hardware device. This is not true, as the /proc/ directory does not contain device files, but only virtual files that represent kernel data. Device files are usually stored in the /dev/ directory, which is another special file system that provides access to hardware devices.
• C. One file per existing user account. This is not true, as the /proc/ directory does not contain information about user accounts, but only about processes. User accounts are usually stored in the /etc/ directory, which contains configuration files, such as /etc/passwd/ and /etc/shadow/, that define the users and their passwords.
• E. One log file per running service. This is not true, as the /proc/ directory does not contain log files, but only information files. Log files are usually stored in the /var/log/ directory, which contains various files that record the activities of the system and the services.

References:

• The /proc Filesystem — The Linux Kernel documentation
• A Beginner’s Guide to the /proc File System in Linux - Tecmint
• Appendix E. The proc File System Red Hat Enterprise Linux 6 | Red Hat …
• Chapter 5. The proc File System Red Hat Enterprise Linux 4 | Red Hat …
• proc file system in Linux - GeeksforGeeks

The su command stands for substitute user or switch user. It allows you to run a shell or a command as another user, usually the superuser or root. To use the su command, you need to know the password of the target user. For example, if you want to switch to the root user, you can type su - and enter the root password. This will give you a root shell, where you can execute commands with administrative privileges. To exit the root shell, you can type exit or press Ctrl-D. The su command is not the default shell of the root account, nor can it only be used by the root user. It can be used by any user who knows the password of another user. The su command does not change the name of the main administrator account, which is always root on Linux systems. The su command also does not lock the root account in specific time frames, although there are other ways to do that, such as using the pam_time module. References:

• Linux Essentials - Linux Professional Institute (LPI), section 5.1.1
• LPI Linux Essentials Study Guide: Exam 010 v1.6, 3rd Edition, chapter 9, page 219.

Section: (none)

 The correct device name that represents a hard disk partition is /dev/sda2. This device name follows the Linux convention for naming hard disk devices and partitions. According to this convention123:

• The first part of the device name indicates the type of the device. For example, /dev/hd* for IDE drives, /dev/sd* for SCSI, SATA, USB, or eSATA drives, /dev/nvme* for NVMe drives, etc.
• The second part of the device name indicates the order of the device as detected by the system. For example, /dev/sda is the first serial drive, /dev/sdb is the second serial drive, and so on.
• The third part of the device name indicates the number of the partition on the device. For example, /dev/sda1 is the first partition on the first serial drive, /dev/sda2 is the second partition on the first serial drive, and so on.

Therefore, /dev/sda2 means the second partition on the first serial drive, which is a valid hard disk partition. The other options are not valid hard disk partitions, because they do not follow the Linux convention. For example:

• /dev/ttyS0 is a serial port device, not a hard disk device4.
• /dev/sata0 is not a valid device name, because it does not specify the partition number. It should be something like /dev/sata0p1 or /dev/sata0p2, etc.
• /dev/part0 is not a valid device name, because it does not specify the device type or the partition number. It should be something like /dev/sdXp0 or /dev/hdXp0, etc.
• /dev/sda/p2 is not a valid device name, because it uses a slash (/) instead of a number to indicate the partition. It should be something like /dev/sda2 or /dev/sda3, etc.

References: 1: Hard drive/device partition naming convention in Linux - Unix & Linux Stack Exchange 2: Hard drive partition naming convention in Linux - Ask Ubuntu 3: C.4. Device Names in Linux - Debian 4: What is /dev/ttyS0? - Quora

Explanation

A web server is a program that listens for requests from web browsers and serves web pages, images, or other resources. Apache HTTPD and NGINX are two popular web servers that can run on Linux systems. They can handle multiple protocols, such as HTTP, HTTPS, FTP, and SMTP. Postfix, Curl, and Dovecot are not web servers, but they are related to web or network services. Postfix is a mail transfer agent (MTA) that can send and receive emails. Curl is a command-line tool that can transfer data from or to a web server. Dovecot is a mail delivery agent (MDA) that can store and retrieve emails from a local mailbox. References:

• Linux Essentials - Linux Professional Institute (LPI), section 1.2 Major Open Source Applications
• LPI Linux Essentials 010-160 - Testprep Training Tutorials, section 4.4 Your Computer on the Network

The passwd command in Linux is used to change the password of a user account. A normal user can run passwd to change their own password, and a system administrator (the superuser) can use passwd to change another user’s password, or define how that account’s password can beused or changed1. The passwd command can also be used to lock or unlock a user account. Locking a user account means disabling the user’s ability to log in to the system, while unlocking a user account means restoring the user’s ability to log in. To lock a user account, the passwd command can be used with the -l option, followed by the username. To unlock a user account, the passwd command can be used with the -u option, followed by the username12. The passwd command cannot be used to change a user’s username, create a new user account, or create a new user group. These tasks require different commands, such as usermod, useradd, orgroupadd345. References: 1: Linux Passwd Command Help and Examples 2: Passwd command in Linux: 8 Practical Examples 3: usermod(8) - Linux man page 4: useradd(8) - Linux man page 5: groupadd(8) - Linux man page

The useradd command in Linux is used to create new user accounts on the system1. The -m option tells the command to create the user’s home directory as /home/username and copy the files from /etc/skel directory to the user’s home directory2. The /etc/skel directory contains the default configuration files for new users3. Therefore, the command useradd -m tux will add the new user tux and create the user’s home directory with default configuration files. The other options are either invalid or do not create the user’s home directory. References:

• Linux Essentials Version 1.6 Objectives, Topic 1.4: Command Line Basics, Subtopic: Basic Shell Commands
• Linux Essentials Version 1.6 Exam Preparation Guide, Section 1.4: Command Line Basics, Page 16
• Linux useradd Command Tutorial for Beginners (15 Examples)