Question

***********PLEASE NO COPYING OR PLAGIARISM!!!! ALSO NO HAND WRITTEN RESPONSE!!!! THANK YOU!!! MUST BE ORIGINAL. ALSO PLEASE COMPLETE IDEAS, MUST BE ABLE TO UNDERSTAND WHAT IS BEING SAID FOR A THUMBS UP ****

Pertaining to the Linux operating system, which is a variant of Unix. The effort will help students understand how the concepts learned in the course relate to one another and how Linux is used in practice.

• A narrative expanding the key points from the prior document, including the following:

  • Definitions, explanations, and examples in your own phrasing

  • Personal experiences, if there are any

  • Personal thoughts and opinions about the topic

  • Your conclusions about the topic

Answer 1

LINUX

What is Linux?
Linux is a open source operating system. It is a version of UNIX.

History
Linux development started in the year 1991 by a Finnish student named Linus Torvalds. Early at the time of its development, the Linux source code was made free on the Internet so that everyone can compose their version.
The 1st Linux kernel was released to the public with Version 0.01, on May 14 in 1991. In 1992, Linus Torvalds released the kernel under GNU(General Public License).

Features
Multiuser capability: Multiple users can access the same system resources like memory, hard disk, etc using different terminals.

Multitasking: More than one operation can be performed simultaneously by dividing the CPU time.

Portability: Portability means it support different types of hardware.

Security: It provides security in by authenticating, authorization and encryption.

Live USB: Almost all Linux distros provide live USB so that users can run it without installing it also.

Application support: It has its own software repository from where users can download and install applications.

File System: It provides hierarchical file system in which files and directories are arranged.

Open Source: Linux code is freely available to all. Its a community based development project.

Components of the Linux Operating System

Bootloader – It software manages the computer’s boot process.

Kernel – It is the core of the system and manages the computer’s CPU, memory, and peripheral devices.

Daemons – They are the background services such as printing and scheduling are handled by daemons.

Shell – It is also known as the Linux command line, in the early days of the operating system this was the only way to control any computer. It required commands to be entered in a text. Modern desktop implementations of Linux have made it possible to use the operating system without having to master the command line.

Graphical Server – It is the sub-system responsible for displaying the graphics on your machine and is called the X server.

Desktop Environment – There are different desktop environments such as GNOME, Cinnamon, and KDE. This is the window through which the user interacts with the operating system to achieve there task.

Applications – There are thousands of applications present that can be downloaded and installed to extend to functionality of your Linux implementation.

Linux File Structure
Linux has an extensive default directory structure. These directories can be found by executing the “tree -L 1 /“ command. The directories we are going to discuss are the top level directories located under the root directory.

/bin – It contains binaries which are some of the applications and programs that can be executed.
/boot – The files required for system startup are in this directory.
/dev – This is a virtual directory and it contains device files associated with peripheral devices attached to your system.
/etc – contains system-wide configuration files.
/home – User's personal directories are located at this directory.
/lib – This directory contains libraries that contain the code required by the system’s applications.
/media – External storage is automatically mounted in this directory when it is plugged into your system.
/mnt – This directory used to manually mount storage devices or partitions.
/opt – It often contain software that you have compiled.
/proc – This is another virtual directory that contains information about your CPU and Linux kernel.
/root – This is the home directory of the superuser or administrator.
/run – It is used to store temporary data from system processes.
/sbin – It contains binaries that only the superuser will need.

Modern Linux distributions are using the directory for various application and service-related files.
/srv – It contains data for servers.
/sys – It is a virtual directory that contains device information.
/tmp – It is used for storing temporary files from users and applications.
/var – It logs and task spools are found in this directory.

Some Basic Linux Commands

ls – This command displays the contents of the current working directory. Using the variant ls -l gives long form information and ls -a also will show you any hidden files in the directory.
pwd – This command displays the current working directory is displayed.
cd – This command displays change to your home directory. Appending a space and a name will switch you to the named directory. Appending two periods will bring you to the current directory’s parent directory.
mkdir – This command create a new directory.
mv – This command rename or move files and directories.
uname – This command displays information regarding the machine name and operating system. Use uname -a to obtain detailed information.
history – This command list the recently executed commands entered through the command line.
touch – This command create a file that does not already exist.
chmod – This command is used to change the read, write and execute file permissions.
more – This command displays multiple pages of information one screen at a time. Hitting enter will show you the next screen.
locate – This command used to find a file’s location by name.
man – Shortform for manual, it displays the reference manual pages for a specified command. Entering man ls will show what the manual has on the ls command.
kill – This command is used to kill a process by name.
ip – This command displays and manages routing, devices, and can be used to assign an IP address to a specific interface.
grep – This command used to search for a specified pattern or string in files.
du – This command displays disk space usage of files in a directory.
cp – This command used to copy files and directories from one location to another.
passwd – This command allows you to create or update passwords for user accounts.
cat – This command used to view and add to a text file.
sudo – This command allows an authorized user to execute commands as the root user of the system.
vim/vi – By executing this command you to edit text and program files.

Linux Files and File Permissions
The ability of users and applications to access files and directories depends on their file permissions.

Read – The linux serial port test program Read permission enables the user to view the contents of a file and view the names of files contained in a directory.
Write – Having this permission lets a user modify or delete a file. Combined with the execute permission, you can modify the contents of a directory.
Execute – This permission lets you execute a file if the read permission is also enabled. It is used with the write permission for modifying directories and the files they contain.

Linux also have the control of a user who can exercise over a file or directory by the use of groups. A group is a collection of zero or more users that may have common requirements. File and directory permissions are assigned to three entities:

User – This permission impact the file’s owner.
Group – This permission affect the group that owns the file. When the owner is in the group, User permissions are enforced.
Other – All other users comes under this permission.

Linux Services, Daemons, and Devices
Linux services and daemons are essentially applications that run the background. They are not under the direct control of the user. System events may initiate action by the services or by the daemons.

Networking with Linux
Linux machines are often used as network gateways or firewalls. The reliability of the OS, its cost-effectiveness, and its flexibility make it a prime candidate for use in servers and devices involved in networking. There are Linux distributions that are customized for the needs of network administrators.

Some of the more useful Linux networking commands:
ifconfig – it is used to configure the parameters of network interfaces.
telnet – it tests connectivity between two hosts.
netstat – it allows you to review network connections.
scp – it is used to copy files securely between hosts.
nmap – it checks opened ports.