Has been originally written in the programming language C, and it is mainly used for scientific-technical applications on mainframes and workstations but has also become perfectly suited for application in networks.

UNIX

Interfaces to the operating system, the kernel of the host

Shells

A graphical representation in which the users can interact with software or devices through graphical icons.

GUI (Graphical User Interface)

A console or text-based representation in which the user types the commands to operate the software or devices.

CLI (Command-Line Interface)

was once the most popular Linux desktop environment and was used by default on Ubuntu, Fedora, Debian, and most other big Linux distributions.

GNOME

has always been more complex than GNOME, packing in many more configuration options and features.

KDE

Is a more lightweight desktop environment, very similar to GNOME.

xfce

Was developed for Linux Mint in which it is based on GNOME. It uses up-to-date libraries and other software — but it takes that software and tries to create a more traditional-looking desktop with it.

Cinnamon

displays user manual of any command on the terminal

man

determines the type of a file.

file

displays short descriptions of program

whatis

locates files and pages of a command

whereis

displays the current user

whoami

displays the list of files and directory

displays the contents of the working directory recursively showing sub-directories and files, and a summary of the total number of sub-directories and files

tree

displays parent working (Parent directory

pwd

changes the current directory - cd .. - previous folder - cd / - root folder - cd ~ - shortcut

creates director

mkdir

removes directory

rmdir

copies a file to a specified location

moves a file to a specified location

removes a file.

It is a file on the system that contains data, text, or program instructions.

Ordinary Files

They store both special and ordinary files. For users familiar with Windows or Mac OS, Unix directories are equivalent to folders.

Directories

Some files provide access to hardware such as hard drives, CD-ROM drives, modems, and Ethernet adapters.

Special Files

refersto the root directory. The root directory is the one from which all other directories branch off from.

is the directory that contains binaries, that is, some of the applications and programs you can run.

/bin

directory contains files required for starting your system.

/boot

contains device files. Many of these are generated at boot time or even on the fly.

/dev

the dumping ground for system files administrators were not sure where else to put.

/etc.

where you will find your users’ personal directories.

/home

where libraries live. Libraries are files containing code that your applications can use.

/lib

the dumping ground for system files administrators were not sure where else to put.

/etc.

directory is often where the software you compile.

/opt

are virtual directory in which it contains information about your computers, such as information about your CPU and the kernel your Linux system is running.

/proc and /dev

similar to /bin, but it contains applications that only the superuser will need.

/sbin

directory was where users’ home directories were originally kept back in the early days of UNIX.

/usr

contains temporary files, usually placed there by applications that you are running.

/tmp

was originally given its name because its contents were deemed variable in which it contains files to which the system writes data during the course of its operation.

/var

It is a series of related instructions that tells the computer what task(s) to do and how to perform them.

Software

a set of programs that coordinates all the activities among computer hardware devices.

Operating system

allows a user to perform maintenance- type tasks usually related to managing a computer, its devices, or its programs.

Utility Program

consists of programs designed to makes users more productive and/or assist them with personal tasks.

Application Software

Is the software essential? Will it help you accomplish an important task?

Necessity

What resources does the software require? It includes hard disk storage space, main memory capacity, and specific platform.

Requirements

Does the software come with warranty/support? Software might have issues upon installation and usage and such would require fixes and updates.

Support

a program used to install, update, upgrade, or remove software

Package Manager

can install software from an RPM file

Rpm (Red Hat Package Manager)

a front-end tool for rpm so that a user has a minimal amount to issue when trying to install RPM files.

Yum (Yellowdog Updater Modifier)

A command-line packager tool for Debian Linux.

Apt (Advance Packaging Tool)

Installs the package

-i

Upgrades the packages

-U

Freshens the package

-F

Erases the package

-e

What is the syntax for installing an rpm file

rpm [option] file(s)

yum instruction has 3 parts

Command, Package name, options

Checks to see if there are any upgrade available for installed software

-checkupdate

Cleans up the yum cache directory

-clean

Attempts to downgrade a package from the current version to previous versions (if available)

-downgrade

Applied on a list of packages

groupinstall grouplist groupremove groupupdate

Provides description and summary of the available package

-info

Lists any package that provides a given feature or file

-provides

Uninstalls and then installs the specified package again

-reinstall

Lists packages that fulfill a given dependency

-resolvedep

Searches all packages’ summaries for the given string for matches

-search

Updates an installed package to the specified version

-update-to

Lists available repositories

-repolist

Which yum command is correct

yum install emacs

software libraries required to complete the installation of a given piece of software.

Package Dependencies