Linux Prelims

operating system (OS)

is the sum of all programs which are required to operate a computer.

UNIX

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.

UNiplexed Information and Computing System

What does UNIX stand for?

Linux

is a family of UNIX-like open-source operating system developed by Linus Torvalds.

Linux distribution (distro)

is a collection of software on top of a Linux kernel.

Linux distribution (distro)

aims to provide a common look and feel, secure and easy software management, and often a specific operational purpose.

Shells

are interfaces to the operating system, the kernel of the host. It provides the necessary instruction and operation that an operating system may process

GUI (Graphical User Interface)

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

CLI (Command Line Interface

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

GNOME

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

KDE

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

Xfce

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

Cinnamon

was developed for Linux Mint in which it is based on GNOME.

man

displays user manual of any command on the terminal

file

determines the type of a file.

whatis

displays short descriptions of program

whereis

locates files and pages of a command

whoami

displays the current user

ls

displays the list of files and directory

tree

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

pwd

displays parent working directory

cd

changes the current directory

cd ..

command for changing directory to previous folder

cd /

command for changing directory to root folder

cd ~

command for changing directory to shortcut

mkdir

command for creating directory

rmdir

command for removing directory

cp

command for copying a file to a specified location

mv

command for moving a file

rm

command for removing a file

Ordinary Files

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

Directories

store both special and ordinary files.

Special files

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

/

refers to the root directory

/bin

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

/boot

directory contains files required for starting your system.

/dev

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

/etc.

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

/home

is where you will find your users’ personal directories.

/lib

is where libraries live.

/opt

directory is often where the software you compile.

/proc and /dev

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

/sbin

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

/usr

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

/tmp

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

/var

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.

Software

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

System software

consists of the programs that control or maintain the operations of the computer and its devices.

Operating system

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

Utility program

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

Application software

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

Package manager

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

rpm

can install software from an RPM file

yum

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

apt

is a command-line packager tool for Debian Linux.

Red Hat Package Manager

What does rpm stand for?

Yellowdog Updater Modifier

What does yum stand for?

Advanced Packaging Tool

What does apt stands for?

-i

Command line for installing the package

-U

Command line for upgrading the package

-F

Command line to freshen the package

-e

Command line to erases or removes the package

Package dependencies

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