Linux Essentials Final Exam (Modules 9 – 16)

The fdisk command is indeed a tool used for working with the MBR partitioned disks. It allows users to create, delete, and manage partitions on a disk. This command is commonly used in Linux and Unix systems to manage disk partitions. Therefore, the given answer "True" is correct.

The correct answer is "top" because the "top" command in Linux continuously updates and displays real-time information about running processes, including CPU and memory usage, process IDs, and more. It provides a dynamic view of the system's performance and allows users to monitor and manage processes effectively.

The option "-n" in the netstat command displays information as numbers rather than names. This means that instead of showing the names of the network connections, it will display the corresponding numerical IP addresses and port numbers. This can be useful for troubleshooting network issues or for obtaining a more detailed understanding of the network connections.

The correct answer is "ssh nick@server1". This command uses the SSH protocol to log into the machine named "server1" with the account name "nick". The "@" symbol is used to separate the account name from the server name in SSH commands.

Sudo privileges allow for the specification of which user can use the sudo command to execute commands as other users. This means that certain users can be granted the ability to temporarily elevate their privileges and perform tasks that are typically restricted to other users or the root user. Therefore, the statement that sudo privileges can be used to specify which user can use the sudo command to execute commands as other users is true.

A host refers to a device or a computer system that is connected to a network and is capable of sending or receiving data. In this context, a printer attached to the network via an IP address can be considered a host as it is connected to the network and can receive print jobs from other devices on the network. The computer's hard drive, network cable, and CDROM are not considered hosts as they do not have the capability to send or receive data on a network.

MBR (Master Boot Record) and GPT (GUID Partition Table) are valid partitioning types. MBR is a traditional partitioning scheme used on BIOS-based systems, while GPT is a newer partitioning scheme commonly used on UEFI-based systems. Both MBR and GPT allow for the division of a storage device into multiple partitions, each with its own file system. PC and BIOS, on the other hand, are not valid partitioning types and do not refer to any specific partitioning schemes.

The correct answer is "1 will be added to the i variable." This is because the expression $(( $i + 1)) is an arithmetic expansion in bash, where the value of i is incremented by 1. The double parentheses $(( )) are used to perform arithmetic operations in bash, and in this case, it adds 1 to the value of i.

The command "last" can be used to determine a user's most recent log in. This command displays a list of the most recent logins, including the date, time, and duration of each session. It provides information about the user's activities and can be helpful for monitoring user access and detecting any unauthorized logins.

The correct answer is /etc/shadow because this file is commonly used in Unix-based systems to store encrypted user password information. It is accessible only by the root user, providing an extra layer of security. The /etc/passwd file, on the other hand, contains user account information but does not store encrypted passwords. The /etc/usr and /etc/group files are unrelated to password information.

The given statement is false. The /etc/shadow file does not contain plain-text passwords. It is a system file on Unix-like operating systems that stores encrypted user passwords. The passwords are hashed and salted, providing an extra layer of security compared to storing them in plain text. This helps protect the passwords from being easily compromised in the event of a security breach.

A source and a hard link must be part of the same filesystem because a hard link is a direct reference to the same inode (data structure that stores information about a file) as the source file. In other words, a hard link creates a new file entry in the filesystem that points to the same data blocks as the source file. Therefore, both the source file and the hard link must be located within the same filesystem.

DVI (Digital Visual Interface) and VGA (Video Graphics Array) are both valid video cable connector types. DVI is a digital video connector commonly used to connect a computer to a monitor or projector. It supports high-quality video signals and can transmit both digital and analog signals. VGA, on the other hand, is an older analog video connector that is still widely used. It is commonly found on older computers and displays and can support lower resolutions compared to DVI. Both DVI and VGA connectors are commonly used in the video industry and are compatible with various devices.

The files /etc/shadow and /etc/passwd contain user account information. The /etc/shadow file stores encrypted passwords for user accounts, while the /etc/passwd file contains basic user account information such as usernames and user IDs. These files are commonly used in Unix-like operating systems to manage user accounts and authentication.

In distributions that do not allow the root user to login directly or via the su command, the installation process automatically configures one user account to be able to use the sudo command to execute commands as if they were executed by the root user. This means that the user account has the necessary privileges to perform administrative tasks without actually logging in as the root user. Therefore, the statement is true.

The file "/etc/passwd" contains user IDs. This file is a system file in Unix-like operating systems that stores essential information about each user account on the system, including the user ID. It is used by various system utilities and processes to identify and authenticate users. The "/etc/group" file, on the other hand, contains information about user groups, while the "/etc/shadow" file stores encrypted passwords. The "/etc/usr" file mentioned in the options does not exist and is likely a typo or incorrect option.

The groupadd command uses the /etc/group file to determine the new GID when a GID isn't specified. This file contains information about groups on the system, including their names, GIDs, and the users who are members of each group. By checking this file, the groupadd command can assign a unique GID to a new group that is being created.

The command "rpm -qa" is used to get a list of all packages installed on a system using RPM Package Management. This command queries the RPM database and returns a list of all installed packages.

The chmod command allows the file owner and root to modify the permissions of a file. The file owner has the authority to change the permissions of their own files, while root, being the superuser, has the highest level of privilege and can modify the permissions of any file on the system. Other users who belong to the file's current group can also use the chmod command to modify the file's permissions. However, only root has complete control over all files and can modify any file's permissions.

The correct answer is "ln -s file link" because the "-s" option is used to create a symbolic link. The "file" is the original file that we want to link, and "link" is the name of the symbolic link that will be created.

The correct answer is "test $USERS –eq 5". This is the correct way to test if the value of the variable USERS is equal to 5. The "-eq" operator is used to check for equality in shell scripting. Therefore, this command will evaluate to true if the value of USERS is indeed 5, and false otherwise.

A conditional that lets you make multiple comparisons with a pattern is called a "case". This is because a case statement allows you to evaluate multiple conditions and execute different blocks of code depending on the value of the variable being evaluated. It is commonly used when there are multiple possible outcomes or conditions that need to be checked against a single variable.

The correct answer is /dev/hda. In Linux systems, device files are used to access hardware devices. The /dev/hda file represents the first IDE hard drive on the system. The "hda" naming convention is commonly used for IDE hard drives, with "hd" indicating a hard drive and "a" representing the first drive. Therefore, /dev/hda is the valid device file name for the first IDE hard drive on the system.

The option "-R" for the chown command can be used to change the owner of a directory and all the files and directories below it. This option stands for "recursive" and allows the change of ownership to be applied to all subdirectories and files within the specified directory. By using this option, the ownership of the entire directory tree can be modified in one command.

By default, when a file is created, the "execute" permission is not set. This means that the file cannot be executed as a program or script directly. This is a security measure to prevent accidental execution of potentially harmful files. The user must explicitly set the "execute" permission if they want the file to be executable. Therefore, the statement "The 'execute' permission is never set on files by default" is true.

A source file and a symbolic link do not have to be part of the same file system. Symbolic links can be used to refer to files or directories in different file systems, allowing for flexibility and organization in file management. Therefore, the correct answer is False.

The statement is false because the user owner of a file can have lower permissions than "other". The user owner can have specific permissions set for themselves, while "other" refers to all other users who are not the owner. Therefore, it is possible for the user owner to have more restrictive permissions than "other".

When a source file is deleted, any symbolic links pointing to it will become invalid or broken. Symbolic links are essentially shortcuts or references to the original file, and if the original file is deleted, the link will no longer be able to access it. Therefore, deleting a source file will break any associated symbolic links.

The command "getent" can be used to view the /etc/passwd file entries. This command is used to retrieve entries from databases configured in /etc/nsswitch.conf, including the passwd database which contains user account information. By running "getent passwd", the user can view the list of users and their corresponding details stored in the /etc/passwd file.

The correct answer is /etc/sysctl.conf. This file is used to configure kernel parameters and allows entries to be added to make changes permanent for kernel parameter files found under /proc/sys. By adding entries to /etc/sysctl.conf, the changes will persist even after a system reboot.

The chown command can accept multiple files as arguments, not just one file at a time. This allows the user to change the ownership of multiple files simultaneously, saving time and effort.

The correct answer is "usermod -L bob". The "-L" option in the usermod command locks the user account, preventing the user from logging in.

The question is asking for the valid Linux option styles. The correct answer is Traditional Unix with a single dash (-), BSD Unix without a dash, and GNU long options with two dashes (–). These are the commonly used option styles in Linux. The Traditional Unix style uses a single dash before the option, BSD Unix style does not use a dash, and GNU long options style uses two dashes before the option. DOS slash style is not a valid Linux option style.

The /proc/cmdline file contains the information passed to the kernel at boot time. This file provides the command line arguments that were used to boot the kernel, including options such as the kernel version, root device, and other parameters. It is a virtual file that can be accessed to view or modify the command line arguments used during the boot process.

The correct answer is "test –d /tmp/foo –o $USERS –gt 5". This answer uses the "test" command with the "-d" flag to check if "/tmp/foo" is a directory. It also uses the "-o" flag to combine this condition with the condition that "$USERS" is greater than 5. This test will return true if either condition is met.

The RSA key fingerprint does not allow the dig command to connect to remote systems. The dig command is primarily used for DNS queries and does not require or use RSA key fingerprints for its functionality. Therefore, the statement is false.

The correct answer is "ln file link" because the "ln" command is used to create links between files, and the syntax "ln file link" creates a hard link named "link" that points to the file named "file".

The commands "w" and "uptime" can be used to display how long the system has been running since the last boot. The "w" command shows the current system time and the duration since the last boot, while the "uptime" command specifically provides information about the system uptime. Both commands are commonly used in Linux and Unix systems to check the system's uptime.

A division of a hard drive is commonly referred to as a partition or a slice. This is because a hard drive can be divided into separate sections or partitions, each of which can be used to store data independently. These partitions or slices allow for better organization and management of data on the hard drive.

The screen will fill with dots because the script contains a while loop that will continue executing the echo command until the file /tmp/foo exists. The echo command is used to print a dot on the screen.

If a file called /tmp/foo exists, process_data won't be run because the condition in the while loop checks for the existence of the file /tmp/foo using the -f flag. If the file exists, the loop will exit and process_data will not be executed.

process_data will be called at most once because once the file /tmp/foo is created by the process_data command, the condition in the while loop will evaluate to false and the loop will exit. Therefore, process_data will only be called once.

/tmp/foo will be removed if it exists is not true because there is no command or statement in the given script that removes the file /tmp/foo.

Therefore, the correct answers are: If a file called /tmp/foo exists, process_data won’t be run and process_data will be called at most once.