010-160 Exam Dumps : Linux Essentials Certificate Exam - version 1.6

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)

A recursive directory listing is a way of displaying the files and folders in a directory and all its sub-directories. The recursive option can be used with various commands, such as ls, find, or dir, to list the files recursively. For example, the command ls -R will list all the files and folders inthe current directory and any sub-directories, showing the hierarchy of the file system123 A recursive directory listing does not include the permissions, ownership, or file system details ofthe files, unless specified by other options. For example, the command ls -lR will list the files recursively and also show the permissions, ownership, size, and modification date of each file1 A recursive directory listing also does not include a preview of the content of each file, unless specified by other options. For example, the command ls -R --file-type will list the files recursively and also show the file type indicator, such as / for directories, * for executable files, @ for symbolic links, etc1 References: 1: ls (Unix) - Wikipedia 2: Recursively List all directories and files - Stack Overflow 3: Why is ls -R called “recursive” listing? - Ask Ubuntu

 The PATH environment variable is a special variable that contains a list of directories that the system searches when looking for a command to execute12. The purpose of the PATH variable is to make it easier and faster for users to run commands without having to type the full path to the executable file. For example, if you want to run the ls command, which is located in the /bin directory, you don’t have to type /bin/ls every time. You can just type ls, and the system will find the executable file in the /bin directory, which is one of the directories in the PATH variable. The PATH variable can be viewed with the echo command12:

$ echo $PATH

The PATH variable can also be modified by adding or removing directories, either temporarily or permanently, depending on the user’s needs12. For example, if you have acustom script or program in your home directory, and you want to run it from anywhere, you can add your home directory to the PATH variable with the export command12:

$ export PATH=$PATH:~/myprogram

This will append your home directory to the end of the PATH variable, and the system will search it last when looking for a command. To make this change permanent, you need to edit a configuration file, such as ~/.bashrc or ~/.profile, and add the export command there12.

References:

• How To View and Update the Linux PATH Environment Variable | DigitalOcean
• Linux path environment variable - Linux command line - LinuxConfig.org