Linux

Open Source Software

Software that conforms to an Open Source license is therefore Open Source Software.

Beta and Stable

Some distributions differentiate between stable, testing, and unstable (beta) releases. The difference being that unstable releases trade reliability for features. When features have been integrated into the system for a long time, and many of the bugs and issues addressed, the software moves through testing into the stable release.

BSD

Some of the Open Source licenses are the BSD family of licenses, which are much simpler than GPL. They merely state that you may redistribute the source and binaries as long as you maintain copyright notices and don't imply that the original creator endorses your version.

cp -R

Sometimes you want to see not only the contents of a directory, but also the contents of the sub-directories

/boot

The /boot directory contains files to boot the computer.

echo

The ____ command helps us move some data, usually text into a file

locate

The ____ command is used to locate a file in a Linux system, just like the search command in Windows

&& AND Operator

The ____ would execute the second command only, if the execution of first command SUCCEEDS, i.e., the exit status of the first command is 0. This command is very useful in checking the execution status of last command.

Concatenation Operator (\)

The _____ as the name specifies, is used to concatenate large commands over several lines in the shell.

;

The ______ operator makes it possible to run, several commands in a single go and the execution of command occurs sequentially

AND - OR operator (&& - ||)

The above operator is actually a combination of 'AND' and 'OR' Operator. It is much like an 'if-else' statement.

cd(change directory

Use the __ command to go to a directory

ls (list)

Use the____command to know what files are in the directory you are in

Maintenance Cycles

Various distributions also have release cycles, sometimes as often as every six months. While upgrades are not required, each version can only be supported for a reasonable length of time.

history

gives a list of all commands used and how many times

Scientific Linux

is an example of a specific use distribution based on Red Hat. The project is a Fermilab sponsored distribution designed to enable scientific computing

Debian

is more of a community effort, and as such, also promotes the use of open source software and adherence to standards. came up with its own package management system based on the .deb file format.

OR Operator (||)

is much like an 'else' statement in programming. The above operator allow you to execute second command only if the execution of first command fails, i.e., the exit status of first command is '1'.

NOT Operator (!)

is much like an 'except' statement. This command will execute all except the condition provided.

Ubuntu (LTS)

is the most popular Debian derived distribution.

Linux Mint

was started as a fork of Ubuntu Linux. There are various versions, all free of cost, but some include proprietary codecs.

Python

Python is another scripting language that is in common use. It makes complex tasks easier and has a framework called Django that makes building web applications very easy.

FOSS

Rather than dwell over the finer points of Open Source vs. Free Software, the community has started referring to it all as Free and Open Source software (FOSS).

Samba

Samba allows a Linux machine to look like a Windows machine so that it can share files and participate in a Windows domain.

MySQL

A database stores information and also allows for easy retrieval and querying. The most popular databases here are MySQL and PostgreSQL.

dpkg, apt-get, rpm, yum

A package manager takes care of keeping track of which files belong to which package and even downloading updates from a remote server called a repository. On Debian systems the tools include dpkg, apt-get, and apt-cache. On Red Hat derived systems, you use rpm and yum.

GPL

A set of licenses developed by the FSF, such as the GPLv2 and GPLv3, and the Lesser GPL licenses versions 2 and 3 (LGPLv2 & LGPLv3).

sudo(SuperUser do)

A widely used command in the Linux command line

nginx

Another web server is nginx, which is based out of Russia. It focuses on performance by making use of more modern UNIX kernels and only does a subset of what Apache can do.

GIMP

Application that handles 2D image manipulation.

privacy issues and tools

As a general rule, you should not trust sites you interact with. Use separate passwords on each website so that if that website is hacked, the password can't be used to gain access to other sites. Using KeePassX is the easiest way of doing this. Also, limit the information you give to sites to only what is needed.

shell

At the basic level, you interact with a Linux system through a shell no matter if you are connecting to the system remotely or from an attached keyboard. The shell's job is to accept commands, such as file manipulations and starting applications, and to pass those to the Linux kernel for execution.

terminal

Each Linux desktop is different, so you will want to look around your menus for an option called either "terminal" or "x-term". Both of those are graphical shells, differing mostly in appearances rather than functionality.

""

Enclosing characters in ____ preserves the literal value of all characters within the quotes, with the exception of $, `, \, and, when history expansion is enabled, !

' '

Enclosing characters in single quotes ___ preserves the literal value of each character within the quotes

FLOSS

Free/Libre/Open Source Software

Console

If you log in through text-mode, you're immediately at the console

Java

Instead of compiling to machine code, Java first imagines a hypothetical CPU called the Java Virtual Machine (JVM) and compiles all the code to that

Gui vs Command Line

Linux can be used in one of two ways: graphically and non-graphically. In graphical mode your applications live in windows that you can resize and move around. You have menus and tools to help you find what you're looking for. In non-graphical mode, there are no windows to move around. Even though you have text editors, web browsers, and email clients, they're text only

C

Linux itself was written in a compiled language called C. C's main benefit is that the language itself maps closely to the generated machine code so that a skilled programmer can write code that is small and efficient.

OpenOffice, LibreOffice

OpenOffice (sometimes called OpenOffice.org) and LibreOffice offer a full office suite, including a drawing tool that strives for compatibility with Microsoft Office both in terms of features and file formats.

Uses of common open source applications in presentations and projects

OpenOffice, or the more active LibreOffice, takes care of the first three roles. A word processor is used to edit documents, such as reports and memos. Spreadsheets are useful for working with numbers, such as to summarize sales data and making future predictions. A presentation package is used to create slides with features such as text, graphics and embedded video. Slides may be printed or displayed on a screen or projector to share with an audience.

PHP

PHP is a language that was originally built to create dynamic web pages. PHP's main advantages are that it is easy to learn and available on almost any system. Because of this, many popular projects are built on PHP. Notable examples include WordPress (blogging), cacti (for monitoring), and even parts of Facebook.

Perl

Perl was originally developed to perform text manipulation. Over the years, it gained favor with systems administrators and still continues to be improved and used in everything from automation to building web applications.

cp(copy)

The cp command is used to copy files. It requires that you specify a source and a destination. The source is the file you wish to copy. The destination is where you want the copy to be located. When successful, the cp command will not have any output.

password issues

The easiest thing you can do is to use a good, unique password everywhere you go, especially on your local machine. A good password is at least 10 characters long and contains a mixture of numbers, letters (both upper and lower case) and special symbols.

&

The function of ___ is to make the command run in background. Just type the command followed with a white space and ___. You can execute more than one command in the background, in a single go

mkdir

The mkdir command is used to create a directory.

NFS

The native file sharing protocol for UNIX is called the Network File System (NFS).

Open Source business models

The simplest way to make money is to sell support or warranty around the software. You may make money by installing the software for people, helping people when they have problems, or fixing bugs for money. You are effectively a consultant.

home

The term home directory often causes confusion to beginning Linux users. To begin with, on most Linux distributions there is a directory called home under the root directory: /home. Additionally, when you open a shell, you should automatically be placed in your home directory, as this is where you will do most of your work.

PATH environment variable

The term path refers to a list that defines which directories the shell will look in for commands. If you type in a command and receive a "command not found" error, it is because the BASH shell was unable to locate a command by that name in any of the directories included in the path

recursive listing

There will be times when you want to display all of the files in a directory as well as all of the files in all subdirectories under a directory. This is called a recursive listing. To perform a recursive listing, use the -R option to the ls command.

PIPE Operator (|)

This ____ operator is very useful where the output of first command acts as an input to the second command.

Thunderbird

Thunderbird is a full featured desktop email client. Thunderbird connects to a POP or IMAP server, displays email locally, and sends email through an external SMTP server.

rm

To delete a file, use the rm command. The files will be permanently deleted

ls -a

To display all files, including hidden files, use the -a option to the ls command.

mv

To move a file, use the mv command. The syntax for the mv command is much like the cp command. When a file is moved, the file is removed from the original location and placed in a new location.

ls -d

When the command ___ is used, it refers to the current directory, and not the contents/sub-directories within it.

. and ..

While the double dot (..) is used to refer to the directory above the current directory, the single dot (.) is used to refer to the current directory.

rmdir

You can also delete a directory with the rmdir command, but only if the directory is empty

ls -l

You can view the ownership of a file with the -l option to the ls command.

Apache HTTPD

___ is the dominant web server in use today. ___ was originally a standalone project but the group has since formed the ___ Software Foundation and maintains over a hundred open source software projects.

Export

after exporting variable 1, it is now an environment variable. The export command can also be used to make an environment variable upon its creation

CentOS

and others like it (such as Scientific Linux) are largely compatible with RHEL and integrate some newer software, but do not offer the paid support that Red Hat does.

touch

command is used to create an empty file. The touch command doesn't place any data within the new file.

Echo

command that displays text, used to demonstrate globbing in chapter 4

cp -p

copy from the source directory and preserve file attributes

Free Software

does not refer to the price, but to the freedom to share, study, and modify the underlying source code.

Creative Commons

organization has created the Creative Commons Licenses which try to address the intentions behind FOSS licenses for non software entities

Open SUSE

originally derived from Slackware, yet incorporates many aspects of Red Hat.

Red Hat

started out as a simple distribution that introduced the Red Hat Package Manager (RPM). Over time, Red Hat started to focus more on the server applications such as web and file serving, and released Red Hat Enterprise Linux, which was a paid service on a long release cycle.

cp -v or --verbose

switch displays the source and target when the cp command is executed

Bash

the most commonly used shell for Linux distributions is called the BASH shell.

Type

the type command can be used to determine information about various commands

History

to view the history list of a terminal, use the "history" command.

pwd(Present Working Directory)

tool prints the name of the present/current working directory(Present Working Directory)