Linux Skills Assessment - Mop-centric

Explanation
A "man" page refers to a page that provides detailed information about the usage and syntax of a specific Linux command. It serves as a manual or documentation resource for users, helping them understand how to effectively utilize the command and its various options. This page typically includes descriptions, examples, and other relevant details to assist users in performing tasks using the specific command.

Explanation
The command "pwd" stands for "print working directory" and is used to display the current working directory in a command line interface. It is commonly used in Unix-like operating systems, including Linux and macOS. By executing the "pwd" command, the user can easily identify the directory they are currently located in within the file system hierarchy.

Explanation
The correct answer is "cd /tmp". This command is used to change the current directory to the "/tmp" directory. The "cd" command stands for "change directory" and the "/tmp" specifies the directory path. By entering this command, the user's location will be changed to the "/tmp" directory.

Explanation
The "ls" command is used in Unix-based systems to list the contents of the current working directory. It is the equivalent of the "dir" command in Windows. Therefore, selecting "ls" as the answer would display the contents of the current working directory.

Explanation
You can use the "cat" command, the "less" command, the "more" command, the "vi" command, and the "view" command to view the contents of a text file. The "cat" command displays the entire contents of the file, the "less" command allows you to scroll through the file, the "more" command displays the file one screen at a time, the "vi" command opens the file in a text editor where you can view and edit the contents, and the "view" command is similar to "vi" but it only allows you to view the file without editing it.

Explanation
The command "reboot" can be used to reboot the machine. The command "shutdown -r now" can also be used to reboot the machine. Additionally, the command "init 6" can be used to reboot the machine.

Explanation
The command "echo $user" can be used to determine which user you are logged in as. The command "whoami" can also be used for the same purpose. Additionally, the command "id" can be used to determine the user's identity.

Explanation
The "df -k" command is used to display information about the filesystems on a Linux machine, including their sizes and the amount of free space available. The "-k" option is used to display the sizes in kilobytes. This command is commonly used to check the disk space usage on a system.

Explanation
The correct answers are "cat ~/.bash_history | grep service" and "history | grep service".


1. "cat ~/.bash_history | grep service" uses the "cat" command to display the contents of the "~/.bash_history" file, which contains a list of previously entered commands. The "|" (pipe) symbol is used to redirect the output of "cat" to the "grep" command, which filters the output for the string "service".

2. "history | grep service" uses the "history" command to display a list of previously entered commands. The "|" (pipe) symbol is used to redirect the output of "history" to the "grep" command, which filters the output for the string "service".

Explanation
The correct answer is "sed -i "s/foo/bar/" *.txt" because the command uses the sed utility with the -i flag to edit files in-place, meaning it will modify the files directly without creating backup files. The "s/foo/bar/" argument is the substitution command, which replaces the string "foo" with "bar". The "*.txt" specifies that the command should only be applied to files with the .txt extension.