CentOS Package Search – Linux Hint

Whenever you’re looking for a package/software to enjoy, there are several ways you can get that into your Linux system. By default, the fastest and easiest method is to just tell the system’s package manager to install that package. Otherwise, you may need to download the source code, build it by yourself and then, install it.

Hello, CentOS users! In the case of CentOS, the Linux distro is a pretty cool one that gives the complete vibe and feel of the server/enterprise environment. CentOS and RHEL both uses “yum” as the default package manager.

In this case, you have 2 available options for searching a certain package/software – asking “yum” to search by name or, checking the internet for the exact package name.

Don’t worry. Everything is as pretty simple and quick.

As “yum” is the default package manager, you can use the following command structure for searching –

For example, you can search for GNOME using the following command –

Now, that’s LONG list of GNOME and apps!!!

There’s another available GUI tool for searching, listing and installing packages on CentOS – yumex. The package is available on the EPEL repository. THat’s why make sure that your system has EPEL repository enabled –

sudo yum install epel-release

Then, install “yumex” –

Now, fire up “yumex” –

Searching the internet

Now, if you’re out of luck finding out the right package name on your package manager, consider checking out the internet! It’s a faster and more convenient solution for most of us.

The best place for searching for Linux packages is Pkgs.org. It’s a fine place that keeps the record of numerous Linux packages of almost all the popular and non-popular Linux distros you’ll ever enjoy in your machine.

For example, I found the “yumex” package directly on Pkgs.org –

Enjoy!

About the author

Sidratul Muntaha

Student of CSE. I love Linux and playing with tech and gadgets. I use both Ubuntu and Linux Mint.

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January 7, 2019January 8, 2019

The Unix Security Audit and Intrusion Detection Tool

Tiger is a free, open source collections of shell scripts for security audit and host intrusion detection, for Unix-like systems such as Linux. It’s a security checker written entirely in shell language and employs various POSIX tools in the backend. It’s major purpose is to check the system configuration and status.

It’s very extensible than the other security tools, and has a good configuration file. It scans system configuration files, file systems, and user configuration files for possible security problems and reports them.

In this article, we will show how to install and use Tiger security checker with basic examples in Linux.

How to Install Tiger Security Tool in Linux

On Debian and its derivatives such Ubuntu and Linux Mint, you can easily install Tiger security tool from the default repositories using package manger as shown.

$ sudo apt install tiger

On other Linux distributions, you can download the latest source (the current stable release is 3.2.3, at the time of writing) and run it straight away from the terminal as as root or use the sudo command to gain root privileges.

$ wget  -c  http://download.savannah.gnu.org/releases/tiger/tiger-3.2rc3.tar.gz
$ tar -xzf tiger-3.2rc3.tar.gz
$ cd tiger-3.2/
$ sudo ./tiger

By default all checks are enabled, in the tigerrc file and you can edit it using a CLI editor of your liking to enable only the checks you are interested in:

Run Tiger Security Audit Tool on Linux

When the security scan is complete, a security report will be generated in the log sub directory, you will see a message similar to this (where tecmint is the hostname):

Security report is in `log//security.report.tecmint.181229-11:12'.

You can view the contents of the security report file using cat command.

$ sudo cat log/security.report.tecmint.181229-11\:12

View Security Report

If you just want more information on a specific security message, run the tigexp (TIGer EXPlain) command and provide the msgid as an argument, where “msgid” is the text inside the [] associated with each message.

For example, to get more information about the following messages, where [acc001w] and [path009w] are the msgids:

--WARN-- [acc015w] Login ID nobody has a duplicate home directory (/nonexistent) with another user.  
--WARN-- [path009w] /etc/profile does not export an initial setting for PATH.

Simply run these commands:

$ sudo ./tigexp acc015w
$ sudo ./tigexp path009w

View Security Messages

If you want to insert the explanations (more information on a particular message generated by tiger) in the report, you can either run tiger with the -E flag.

$ sudo ./tiger -E

Or if you have already run it, then use tigexp command with the -F flag to specify the report file, for example:

$ sudo ./tigexp -F log/security.report.tecmint.181229-11\:12

View Security Report with Messages

To generate a separate explanation file from a report file, run the following command (where -f is used to specify the report file):

$ sudo ./tigexp -f log/security.report.tecmint.181229-11\:12

As you can see, installing tiger is not necessary. However, if you want to install it on your system for purposes of convenience, run the following commands (use ./configure – -help to check configure script options):

$ ./configure
$ sudo make install

For more information, see the man pages under the ./man/ sub-directory, and use the cat command to view them. But if you have installed the package, run:

$ man tiger 
$ man tigerexp

Tiger project homepage: https://www.nongnu.org/tiger/

Tiger is a set of scripts that scan a Unix-like system looking for security problems – it’s a security checker. In this article, we have shown how to install and use Tiger in Linux. Use the feedback form to ask questions or share your thoughts about this tool.

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January 7, 2019January 8, 2019

CentOS Add Users to Sudoers – Linux Hint

In the case of any Linux system, there’s a very powerful user – the “root”. It upholds the ULTIMATE power over the entire system, even modifying data at the hardware level! That’s why it’s so delicate and dangerous at the same time. Without the “root” access, hackers are forced to follow a trickier and more difficult path for taking over the system.The “root” privilege is responsible for performing all the actions that modifies the system files and packages. That’s why in the enterprise/professional workspace, not all users are allowed to run commands as they wish.

CentOS also comes up with a similar policy. It only allows a certain users to perform actions with the “root” privilege. For example, whenever you run any command with the “sudo” command, you’ll get the following error –

For fixing the issue, the user account must be in the “sudoers” file. In this tutorial, we’ll check out on adding a user into the “sudoers” file.

The trick here is NOT directly editing the “/etc/sudoers” file. Instead, we’ll be adding the specific user into the “wheel” group. In the case of CentOS, all the users in the group have the ability of running “sudo” commands and that’s the easier and safer way.

This is also proven within the “/etc/sudoers” file –

Optional – creating a new user

I’m going to create a new user for the “sudo” purpose only. Don’t worry; you can easily add the existing user.

Enter the “root” mode –

Now, create a new user –

Time to add a password for the newly created username –

It’s finally time to add the user “Yasuo” on the “wheel” group. At first, make sure that you’re logged as the “root” –

Now, perform the final action –

usermod -aG wheel <username>

Everything is set!

Testing the outcome

Well, it’s always worth testing the outcome, no matter how obvious it may seem. Let’s try out running a “sudo” command as “Yasuo” –

Voila! “Yasuo” is now a privileged user account capable of “sudo”!

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January 6, 2019January 8, 2019

DevOps: Get up to speed with these handy guides

Download: “The Ultimate DevOps Hiring Guide” and “The Open Source Guide to DevOps Monitoring Tools”

In 2018, the Open Source DevOps team helped produce two amazing guides to help advance our DevOps practices.

The Ultimate DevOps Hiring Guide

In April, we released The Ultimate DevOps Hiring Guide. It’s a wonderful collection of advice, tactics, and information about the state of DevOps hiring for both job seekers and hiring managers. It starts by discussing the importance of culture for your organization and how it impacts your ability, or inability, to get the right talent on your team. Then it provides an overview of the DevOps hiring landscape and market trends. The final section offers best practices for prospective employees and hiring managers.

Download The ultimate DevOps hiring guide

The Open Source Guide to DevOps Monitoring Tools

In August, contributor and Opensource.com community moderator Dan Barker put together The Open Source Guide to DevOps Monitoring Tools. The extremely popular, in-depth guide walks you through the variety of open source tools available for everything from monitoring to log aggregation and visualization to distributed tracing.

Download The open source guide to DevOps monitoring tools

New guides on the way in early 2019

As we begin the new year, we’ve got two new guides in the works. I’m excited to announce that in early 2019 we plan to have the following guides available for download:

Getting Started with DevSecOps: The Open Source Guide to DevOps Security
Introduction to Small Scale Scrum

Source

January 6, 2019January 8, 2019

Download BusyBox Linux 1.30.0

BusyBox, dubbed by its developers “The Swiss Army Knife of Embedded Linux,” is an open source and freely downloadable software project comprised of a wide range of command-line tools designed to help you interact better with a Linux kernel-based operating system, whether it is installed on a personal computer, laptop, mobile phone or embedded device.

Includes some of the most common Linux/UNIX tools

Some of the most common Linux/UNIX tools, that you’ve most probably used at least once in your life, are included in the BusyBox package, which is usually installed by default on any GNU/Linux or UNIX-like operating system. Among these, we can mention chmod, mount, umount, ps,

It contains all the important command-line utilities

To learn more about the importance of BusyBox into a GNU/Linux operating system, we can tell you that it includes all the mainstream and important command-line utilities that are either used by other command-line or graphical applications, or used directly by you, the user, for various tasks.

For example, it includes all the necessary archiving utilities, such as unzip for extracting zip files, tar for extracting tar archives, as well as bzip2, gzip, rpm, lzop, cpio, ar, bbunzip, dpkg, and rpm2cpio. It also includes many editors, tools for managing file systems, email utilities, find tools, Debian utilities, logging tools, printing tools, and numerous networking utilities.

Can be installed on any GNU/Linux operating system

It BusyBox is not already installed on your GNU/Linux box, you can easily install it by downloading the latest release from its website or via Softpedia, saving the archive on your Home directory, unpacking it using an archive manager tool, and opening a Terminal app.

In the Terminal emulator, go to the location where you’ve extracted the source package (e.g. cd /home/softpedia/busybox-1.23.1), run either of the ‘make oldconfig’. ‘make menuconfig’ or ‘make defconfig’ commands to configure BusyBox, then run the ‘make’ command to compile all tools. Install them system wide by running the ‘sudo make install’ command after a successful compilation.

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January 6, 2019January 8, 2019

Python Matplotlib Tutorial – Linux Hint

Python Matplotlib Tutorial

In this lesson on Python Matplotlib library, we will look at various aspects of this data visualisation library which we can use with Python to generate beautiful and intuitive graphs which can visualise data in a form which business wants from a platform. To make this lesson complete, we will cover the following sections:

What is Python Matplotlib?
Types of Plots we can construct, like Bar Graph, Histogram, Scatter Plot, Area Plot and Pe Chart
Working with Multiple plots
Some alternatives for Python Matplotlib

What is Python Matplotlib?

The matplotlib.pyplot is a graph plotting package which can be used to construct 2-dimensional graphics using Python programming language. Due to its pluggable nature, this package can be used in any GUI applications, Web application servers or simple Python scripts. Some toolkits which extend the functionality of Python Matplotlib are:

Basemap is a map plotting library that provides features to create map projects, coastlines and political boundaries
Natgrid can be used to grid irregular data into spaced data
Excel tools can be used to exchange data between MS Excel and Matplotlib
Cartopy is a much complex mapping library which even provides image transformation features apart from point, line & polygon projections

Just a note before starting is that we use a virtual environment for this lesson which we made with the following command:

python -m virtualenv matplotlib
source matplotlib/bin/activate

Once the virtual environment is active, we can install matplotlib library within the virtual env so that examples we create next can be executed:

pip install matplotlib

We see something like this when we execute the above command:

You can use Anaconda as well to run these examples which is easier. If you want to install it on your machine, look at the lesson which describes “How to Install Anaconda Python on Ubuntu 18.04 LTS” and share your feedback. Now, let us move forward to various types of plots which can be constructed with Python Matplotlib.

Types of Plots

Here, we demonstrate the types of plots which can be drawn with Python Matplotlib.

Simple Graph

The first example we will see will be of a simple graph plot. This example is used as a demonstration of how simple it is to construct a graph plot along with simple customisations that come with it. We start by importing matplotlib and defining the x and y coordinates we want to plot:

from matplotlib import pyplot as plt
x = [3, 6, 9]
y = [2, 4, 6]

After this, we can plot these coordinates on the graph and show it:

plt.plot(x, y)
plt.show()

When we run this, we will see the following graph:

With just few lines of code, we were able to plot a graph. Let us add a few customisations to make this graph a little more expressive:

plt.title(‘LH Plot’)
plt.ylabel(‘Y axis’)
plt.xlabel(‘X axis’)

Add above lines of code just before you show the plot and graph will now have labels:

We will give one more attempt in customising this graph to make it intuitive with the following lines of code before we show the plot:

x1 = [3, 6, 9]
y1 = [2, 4, 6]

x2 = [2, 7, 9]
y2 = [4, 5, 8]

plt.title(‘Info’)
plt.ylabel(‘Y axis’)
plt.xlabel(‘X axis’)

plt.plot(x1 ,y1 , ‘g’, label=‘Quarter 1’, linewidth=5)
plt.plot(x2, y2, ‘r’, label=‘Quarter 2’, linewidth=5)
plt.legend()
plt.grid(True,color=‘k’)
plt.show()

We will see the following plot when we run the above code snippet:

Notice what we started with and what we ended up with, a very intuitive and attractive graph which you can use in your presentations and it is made with pure Python code, definitely something to be proud of !

Making a Bar Graph

A bar graph is specifically useful when we want to platform a comparison with specific and limited measures. For example, comparing the average marks of students with a single subject is a good use-case. Let us construct a bar graph for the same use-case here, the code snippet for this will be:

avg_marks = [81, 92, 55, 79]
physics = [68, 77, 62, 74]

plt.bar([0.25, 1.25, 2.25, 3.25], avg_marks, label=“Average”, width=.5)
plt.bar([.75, 1.75, 2.75, 3.75], physics, label=“Physics”, color=‘r’, width=.5)

plt.legend()
plt.xlabel(‘Range’)
plt.ylabel(‘Marks’)
plt.title(‘Comparison’)

plt.show()

The bar graph created with the above sample data will look like the following:

There are multiple bars present here to establish a comparison. Please note that we have provided the width of each bar as a first parameters and bar is shifted 0.5 values from the previous one.

We can combine this bar graph construction with Pandas library to customise this more but we will cover it in a different lesson on Pandas.

Distributions with Histograms

Histograms are often confused with Bar charts. The most basic difference lies in their use-case. Bar charts are used to establish comparisons between data whereas histograms are used to describe data distribution.

For example, let us apply the example for student marks again but this time, we will only look at the average marks of students and look at how are they distributed. Here is the code snippet, very similar to the previous example:

bins = [0,10,20,30,40,50,60,70,80,90,100]
avg_marks = [81, 77, 55, 88, 81, 66, 51, 66, 81, 92, 55, 51]

plt.hist(avg_marks, bins, histtype=‘bar’, rwidth=0.8)

plt.xlabel(‘Range’)
plt.ylabel(‘Marks’)
plt.title(‘Comparison’)

plt.show()

The histogram created with above sample data will look like the following:

The Y-axis show here that how many students have got the same marks which were provided as the data for the construction.

Making a Scatter Plot

When it comes to comparing multiple variables and establish their effect on each other, Scatter plot is a good way to present the same. In this, data is represented as points with value of one variable reflected by horizontal axis and the value of second variable determines the position of the point on the vertical axis.

Let us look at a simple code snippet to describe the same:

x = [1,1.5,2,2.5,3,3.5,3.6]
y = [75,8,85,9,95,10,75]

x1=[8,8.5,9,9.5,10,10.5,11]
y1=[3,35,3.7,4,45,5,52]

plt.scatter(x,y, label=’10 High scoring students’,color=‘r’)
plt.scatter(x1,y1,label=’10 Low scoring students’,color=‘b’)
plt.xlabel(‘Marks’)
plt.ylabel(‘Student count’)
plt.title(‘Scatter Plot’)
plt.legend()
plt.show()

The scatter plot created with above sample data will look like the following:

Area Plots

The area plots are used mainly to track changes in data over time. They are also termed as stack plots in various texts. For example, if we want to establish a representation of time invested by a student to each subject in a single day, here is the code with which we can do the same:

days = [1,2,3,4,5]

physics =[2,8,6,5,7]
python = [5,4,6,4,1]
r =[7,9,4,3,1]
math = [8,5,7,8,13]

plt.plot([],[],color=‘m’, label=‘Physics’, linewidth=5)
plt.plot([],[],color=‘c’, label=‘Python’, linewidth=5)
plt.plot([],[],color=‘r’, label=‘R’, linewidth=5)
plt.plot([],[],color=‘k’, label=‘Math’, linewidth=5)

plt.stackplot(days, physics, python, r, math, colors=[‘g’,‘k’,‘r’,‘b’])

plt.xlabel(‘x’)

plt.ylabel(‘y’)
plt.title(‘Stack Plot’)
plt.legend()
plt.show()

The area plot created with above sample data will look like the following:

The above output clearly establish a difference in time spent by a student in each subject with a clear way of providing the difference and the distribution.

Pie Charts

When we want to break whole part into multiple parts and describe the amount each part occupies, a pie chart is a good way to make this presentation. It is used to show the percentage of data in complete data set. Here is a basic code snippet to make a simple pie chart:

labels = ‘Python’, ‘C++’, ‘Ruby’, ‘Java’
sizes = [225, 130, 245, 210]
colors = [‘r’, ‘b’, ‘g’, ‘c’]
explode = (0.1, 0, 0, 0) # explode 1st slice

# Plot
plt.pie(sizes, explode=explode, labels=labels, colors=colors,

autopct=‘%1.1f%%’, shadow=True, startangle=140)

plt.axis(‘equal’)
plt.show()

The pie chart created with above sample data will look like the following:

In above sections, we looked at various graphical components we can construct with Matplotlib library to represent our data in various forms and establish differences in an intuitive manner while being statistical.

Features and Alternatives for Matplotlib

One of the best features for matplotlib is that it can work on many operating systems and graphical backends. It supports dozens of Operating systems and graphical output which we looked at in this lesson. This means we can count on it when it comes to providing an output in a way we need.

There are various other libraries present which can compete with matplotlib like:

Even though above mentioned libraries might present some advanced ways to describe and present data in graphical manner but there no denial in the simplicity and effective nature of the matplotlib library.

Conclusion

In this lesson, we looked at various aspects of this data visualisation library which we can use with Python to generate beautiful and intuitive graphs which can visualise data in a form which business wants from a platform. The Matplotlib is one of the most important visualisation library when it comes to data engineering and presenting data in most visual forms, definitely a skill we need to have under our belt.

January 6, 2019January 8, 2019

How to Install the KDE Plasma Desktop on Ubuntu 18.04 LTS

A display manager is the component of your Operating system responsible for launching your display server and the login session. This is the reason it is sometimes called the login manager. The layout of the screen that you see while entering your username and password(the greeter), your login session and user authorization are some of the tasks that the display manager performs. A few common types of default display managers are gdm, gdm3, lightdm, kdm, and sddm, etc.

In this article, we will explain how to install KDE Plasma Desktop and use its sddm display manager for your Linux system. KDE Plasma Desktop is an enriched and beautiful desktop environment that offers high speed, customization, and security while being very simple in use.

We have run the commands and procedures mentioned in this article on a Ubuntu 18.04 LTS system. We will be using the Ubuntu command line, the Terminal, in order to install KDE Plasma on your system. You can open the Terminal application either through the system Dash or the Ctrl+Alt+T shortcut.

Step1: Install Tasksel; a prerequisite for installing Kubuntu

The tasksel command line tool for Ubuntu helps you in installing multiple related packages as a collective task. Ubuntu 18.04 LTS does not have this utility installed by default. Please use the following command as sudo in order to install it on your system as we will later be using it to install Kubuntu Desktop:

$ sudo apt install tasksel

Please note that only authorized users can add/remove and configure software on Ubuntu.

The system might ask you to provide the password for your sudo account. Please enter the password after which the installation procedure will begin. During installation, the system will prompt you with a Y/n option for installation confirmation. Please enter y and hit Enter in order to complete the successful installation of the software.

Step 2: Install Kubuntu Desktop

Now that you have tasksel installed on your system, please enter the following command as sudo in order to install the Kubuntu Desktop:

$ sudo tasksel install kubuntu-desktop

The installation and package configuration procedure will begin as follows:

This process will take some time, depending on your Internet speed and you will be able to see the following output at the end of the installation:

Meanwhile, the system will, ideally, start the configuration process for sddm as follows:

The sddm display manager is the default one for KDE Plasma desktop. Hit Enter for Ok. The system will then offer you to make a selection for configuring sddm as follows:

You can see that my system has two display managers installed on it; gdm3(default for Ubuntu 18.04 LTS) and sddm. Since I have to select sddm, I will use the keyboard down arrow to select it and then hit Enter for Ok.

Workaround if the configuration choice is not presented to you

On some systems, this configuration choice is not presented by itself. For those systems, you manually need to install sddm by using the following apt command as sudo:

$ sudo apt install sddm

Even if that does not initiate the configuration process, it means that like us sddm was already installed on your system. In that case, simply run the following command to manually configure the already installed sddm display manager:

$ sudo dpkg-reconfigure sddm

This command will open the Package Configuration manager as follows:

Use the keyboard down arrow to select sddm and then hit Enter for Ok.

Step 3: Restart your system to login to KDE Plasma

Once you have configured sddm, you now need to restart your system.

On the Login screen of Kubuntu Desktop, select the Desktop Session as Plasma and log in with your existing Ubuntu credentials.

This is how your Kubuntu Plasma Desktop looks like:

You are now in the beautiful environment of the KDE Plasma desktop and ready to enjoy its integrated features. Some procedures on the Internet make it so long to achieve this process that many people leave the installation midway. This article, however, presented the simplest and quickest manner in which you can switch to Kubuntu Plasma.

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January 6, 2019January 8, 2019

Beginner’s Guide: How To Install Ubuntu Linux 18.04 LTS

Two surprising things happened this year in my personal tech life. Dell’s XPS 13 laptop became my daily driver, finally pulling me away from Apple’s MacBook Pro. Then I ditched Windows 10 in favor of Ubuntu. Now I’ve gone down the Linux rabbit hole and become fascinated with the wealth of open source (and commercial!) software available, the speed and elegance of system updates and the surprising turn of events when it comes to gaming on Linux. I’ve also seen a rising interest in Linux inside my community, so I wanted to craft a guide to help you install Ubuntu on your PC of choice.

After you’ve done this, check out my guide to updating your graphics driver and playing Windows-only games on Steam for Linux!

Ubuntu “Circle of Friends” LogoCANONICAL

This installation guide is targeted purely at beginners. I’m a relative beginner myself, so in between the steps we’ll explore why you’re doing what you’re doing rather than just listing instructions. If you’re a Linux pro and spot an error or want to suggest an improvement, please reach out to me on Twitter (@KillYourFM) and I’ll update this guide accordingly.

Ok, you’re here because you’re curious, so let’s chat about why you’d want to consider installing Ubuntu or any other flavor of Linux.

Why You Might Love Using Desktop Linux

Linux distributionsTEAM ENCRYPT / LINUX IN A NUTSHELL 6TH ED.

The most popular operating system in the world is actually built on Linux. Hi Android users! Of course, that’s your phone and not your desktop PC. In that space, Linux has many, many variations called “distributions.” While that can result in an overwhelming amount of choice, it also ushers in freedom of choice which simply isn’t possible using MacOS or Windows. There are flavors of Linux built for students, for musicians and creative professionals, for, um, anime fans? You can even roll your own distribution from scratch and literally make it your own.

Furthermore, Linux is ridiculously customizable. It’s free to download and install (although developers welcome donations). You can throw just about any Linux distribution on a USB stick and test drive it without installing it to your computer. It’s also far more attractive than it used to be, rivaling if not exceeding the user interfaces of Windows 10 or MacOS.

You may simply love Linux because it’s an alternative to Windows 10 at a time when Microsoft is guiding their operating system toward being more of a service they have aggressive control over, and not something that resembles a “personal” operating system for your personal computer.

Why You Might Love Using Ubuntu

The Activities overview screen on Ubuntu LinuxCANONICAL

I previously outlined 5 reasons why you should switch from Windows to Linux, but those are largely subjective opinions. Give it a read and decide for yourself. I’ll quickly summarize them here:

Ubuntu gets out of your way. It doesn’t nag you; it just works
The average user will never need to touch a command line (Terminal) window
Installing software is shockingly easy, and there’s a ton of it. Faster, more secure and more elegant than Windows
System updates are fast, happen in the background, and you aren’t forced to reboot
In my experience the Linux community is incredibly helpful. You don’t be left out in the cold if you have issues

Long story short: Ubuntu pulled me from the shackles of Windows 10, and I haven’t looked back.

PART 1: GET PREPARED

Yep, you can carry around a bootable, persistent, modern OS on this.KINGSTON

Before we install Ubuntu, let’s get everything prepped. I’m going to assume you’re reading this guide from Windows. It’s also assumed that you’re using a 64-bit version of Windows; highly likely if you’re using Windows 7, 8 or 10. (You can do Part 1 on a Mac, but I have less experience with Linux installs on Apple hardware so we’ll stick to traditional PCs)

You’ll need at least a 4GB USB stick and an internet connection.

Step 1: Evaluate Your Storage Space

Let’s not go into this blind. Put some thought into whether you want to completely wipe out Windows, or dual-boot with both Windows and Ubuntu. The installation you’re about to do will give you full control to completely erase your hard drive, or be very specific about partitions and where to put Ubuntu. If you have an extra SSD or hard drive installed and want to dedicate that to Ubuntu, things will be more straightforward. (Don’t worry, you’ll get to choose Windows or Ubuntu when your system boots up.)

If you’re running on a single drive with Windows and are almost out of space, you may want to consider adding that extra drive! Ubuntu doesn’t take nearly as much space as Windows, but assuming you enjoy the experience and want to use it regularly, you’ll appreciate thinking about this ahead of time.

Windows 10 disk management tool. In my example I’ve devoted a spare drive to Ubuntu. It’s not formatted or partitioned yet.MICROSOFT

Because of the variables here, I can’t give you specific instructions for each one. But to check out your current drive situation, click the Windows key (Start button) and type “disk management.” This will show you the number of drives you have, and how they’re partitioned.

Step 2: Create A Live USB Version Of Ubuntu

UNetBootin is a lightweight piece of software that works on Windows, Linux and MacOS. It not only creates a bootable USB stick for you, but it also downloads dozens of different Linux distributions automatically.

UNetBootin websiteGITHUB

Insert your USB stick of choice (make sure there’s nothing on it you want to keep as UNetBootin will format it).

Then, visit unetbootin.github.io/ and download the Windows version. Save it to a location of your choice, or just select “Run” after the download has finished.

UNetbootin Main ScreenGITHUB

Once it launches, select “Ubuntu” from the left dropdown menu. Then you want to select the version. Choose “Ubuntu 18.04 Live x64”. This is the latest “LTS” release. LTS stands for “Long Term Support” meaning that Canonical, the company behind Ubuntu, will support it with regular maintenance and security updates for five years after its release. The “Live” part means that you can try it right from the USB stick without installing anything. And “x64” means that it’s built for modern 64-bit operating systems.

Now, just make sure the right USB stick is selected at the bottom and click OK.

Sidebar: Did you know a Live USB stick can be transported across multiple PCs? It means you can take Ubuntu with you and boot right into it with your saved settings (like WiFi passwords or Firefox bookmarks and logins) and files intact. This is called “persistence” and UNetbootin supports this. To enable it, just look for the “space used to preserve files across reboots” field and set an amount in MB. You can use a minimum of 1MB and a maximum of 4GB. I know people who carry around a Live Linux USB just for their online banking! From a security point of view, not a terrible idea. . .

UNetbootin download progressGITHUB

Sit back and wait while Ubuntu downloads. Then the software will format your USB stick and create a live, bootable USB.

Step 2: Prepare Your PC To Boot From USB

Things may get a little tricky here, but rest assured the answer is out there if you get stuck. You’ve created a bootable USB stick, but you have to your PC to boot from it first. To do that, you may need to go into your system’s BIOS screen, which is accessible only when you first boot your system. (Some PCs may automatically boot to a USB stick if it’s inserted and bootable.)

For the majority of systems, you’ll probably want to hit the “DEL” key right when your PC boots. Sometimes it may be F12, F11, F10 or F2. If in doubt, consult an online manual for your motherboard.

BIOS Screen for my MSI motherboardMSI

Every BIOS screen is different, but I’m using an MSI motherboard so I’m showing that example above. Ordinarily you’ll need to find a category called “Boot” where you’ll see the order your PC looks for devices to boot from. It’s probably set to look at a CD/DVD drive first, and the drive where Windows is installed next. Click on the top or first option and change it to USB. This will probably look something like “UEFI USB Hard Disk” and should have the name of the manufacturer next to it.

While you’re here, I recommend disabling “Secure Boot.” This could save you headaches down the road.

Made it this far? Awesome! Now hit “F10” and select “Save settings and reboot.” (Again the wording may be slightly different on your PC).

Get ready, it’s time install Ubuntu!

PART 2: UBUNTU TEST DRIVE AND INSTALLATIONYou have a bootable Live USB, and your PC should boot from it. When you boot up your system again you should see a text menu with the options to try or install Ubuntu. For now, let’s take it for a test drive. It’s optional, but it will get you familiar with the layout and user interface, see if your WiFi adapter is detected and check if things like resolution and graphics cards are working properly.

Don’t worry about messing anything up here. Have a look around, browse the Software Center and get to know the Settings menus. While you’re in Settings you can connect to your Wireless network, connect Bluetooth devices and adjust your display options among many other things. If you set up “persistence” during the UNetbootin portion of this guide, you’ll be able to reboot and have all your settings saved.

Sidebar: Ubuntu ships with graphics drivers for AMD Radeon cards, and will automatically install a basic, open-source driver for your Nvidia GeForce card. For basic graphics acceleration you shouldn’t need to do anything more out of the box. I’ll get into more detail in the next guide which focuses on gaming (including playing some of your favorite Steam for Windows games!)

Step 1: Starting The Installation

Ready to roll? If you’re just booting up, select “Install Ubuntu.” If you’re taking a test drive, click the top-most icon the dock that says “Install” (it may be a shortcut on the desktop as well).

Installing Linux is so much easier than it used to be, so most of this will be straightforward. Just in case, I’ve tried to capture and represent each basic step.

Select LanguageCANONICAL

Select keyboard layout (you can add additional layouts at any time)CANONICAL

In the opening screens you’ll choose your language and a keyboard layout, which you can change or add to at any time.

Step 2: Get Connected

Get connected!CANONICAL

Then you’ll connect to your wired or wireless network. A wired network (ethernet cable) will be automatically detected and initialized, but you’ll need to choose your Wireless network name and enter a password. Getting connected now means you can download security and feature updates while Ubuntu is installing.

At its core, Linux supports a large number of wireless adapters and they’re normally detected without issue. If yours isn’t, you have many options after the installation, including using a Windows driver! It’s a bit outside the scope of this guide, though. If you need help, check here first. Then holler at @AskUbuntu on Twitter or explore www.AskUbuntu.com.

Step 3: Updates & Other Software

So far so good? Excellent! Now we’re going to add a variable or two to the installation process. First, select “Normal” at the top for the fully featured experience. Most users coming from Windows aren’t going to want a minimal installation.

Additional installation optionsCANONICAL

If you have an internet connection check the box to download updates while installing. And definitely check the box that says “install 3rd-party software.” This will open up options to activate optional Nvidia or AMD drivers, get you loaded up on media codecs for playing a wider range of music and video formats, and in general supply more hardware support out of the box.

Some PCs will have a Secure Boot option here. If so, Ubuntu will ask you for one-time password that you’ll enter here, and then again when your system reboots. Don’t worry, the OS will tell you when it’s going to happen and instruct you what to press. It’ll be during your first post-installation boot. As mentioned earlier, I do recommend disabling Secure Boot altogether in your BIOS.

Sidebar: What is Secure Boot? It’s basically a verification system that makes sure code launched by firmware is trustworthy. A lot of systems shipped with Windows on it have pre-loaded keys that indicate trusted hardware vendors and software providers. When you install some third-party drivers on Linux, Secure Boot will need to be turned off. To the best of knowledge these third-party drivers don’t pose any risk, but it’s a necessary step. If you’re interested in learning more, check out this Wiki.

Step 4: Partition Magic

Now the part that makes people nervous: where to install Ubuntu. Depending on your system’s configuration, you’ll be presented with a couple core options. Do you want to install Ubuntu alongside Windows, or erase a disk entirely for Ubuntu? (Remember that you if you choose to dual-boot Windows on a single disk, you can choose which OS to load during boot.)

Want to erase a disk and have Ubuntu do the partitioning for you?CANONICAL

For erasing a disk, you’ll get to choose which disk in the following screen. If you have that spare drive installed, just choose that and let Ubuntu do all the heavy lifting and auto-partitioning.

Now, both the above options are equivalent to pressing the easy button. Ubuntu will automatically partition your drive. If you’re opting for either of the above, I’ll see at Step 5!

“Something Else” is the exact opposite of easy.

“Something Else” means you don’t want to install Ubuntu alongside Windows, and you don’t want to erase that disk either. It means you have full control over your hard drive(s) here. You can delete your Windows install, resize partitions, erase everything on all disks. So proceed with caution. On the plus side all the changes you make won’t be executed until you click Install. You can always go back or start over.

The example I’m going to use is a system with two drives. One has Windows on it, and I want to leave it untouched. The other is blank.

Partition Manager during Ubuntu setup. Be careful here.CANONICAL

The above example might make your eyes water, and I felt the same way the first few times. Are you SURE you don’t want to just erase your disk and avoid all this? Just kidding! So what do all these letters and numbers mean? Time for a. . .

Sidebar: Here’s how Linux identifies devices. “dev” simply means “a device that you can read from or write to.” Then we see “sda, sda1, sda2,” etc. In Unix “sd” indicates a block device that can carry data. Then it identifies them alphabetically in the order they’re discovered. Finally, the number (1, 2, 3) indicates the partitions. So /dev/sda1 simply means the first partition of the first drive.

Partitions? Think of them as slices of a pie. You can use one entire drive without doing anything to it. Or you can divide it into partitions — logically but not physically separating them. One of my 2TB drives is divided into 1TB partitions. The 2nd partition is just for Steam game installations, so even if I reinstall an operating system, that part of the drive remains intact and loses no data. With Linux, partitions are necessary.

Knowing that, you “Something Else” adventurers will need to add about 4 partitions to your extra drive. I’m going to take you through it step-by-step.

Identify the drive you want to install Ubuntu toCANONICAL

First, identify the drive you want to install Ubuntu to. I know that it’s “sdb” because it lists 1TB of free space and there are no partitions. So, highlight yours (remember it will be the one that looks like “/dev/sdb”and then click “New Partition Table.”

Now you will need to create 3 partitions, beginning with a “Swap Area.”

Create a “Swap Area” partitionCANONICAL

Swap is a small space on the drive that is used like system memory (RAM). As a rule of thumb, you’ll want it to be slightly larger than the amount of RAM you have in your PC. I have 16GB of RAM, so I’m creating a 20GB (or 20000MB) swap partition.

Sidebar: You may be required to create an “EFI Partition” as well, and if so Ubuntu will tell you. The EFI partition is where the boot loader is installed and tells your PC which operating systems can be booted. Sometimes you can install it to your Windows drive, and you’ll notice there’s a drop-down menu to choose where that happens. If you’re asked to create one, just follow the same procedure as all other partitions. Make it 250MB.

Create a Root partition with the EXT4 filesystem.CANONICAL

Then select “/” as the mount point.CANONICAL

Next let’s create our “root” partition using the Ext4 filesystem. (Fun fact: the Ext4 filesystem supports volumes up to 1,152,921,504 GB!) The root partition is the top-most directory of the drive and Linux won’t work without it.

For its size, you can use the remaining space on your drive which should be automatically inserted. Some will argue that a “/home” partition should also be created (think of /home as the account directory in a Windows installation like “C:/Users/Jason.” But Ubuntu will automatically create a “home” folder for your documents, photos, videos and other media and files. It’s very easy to back up or transfer to another Ubuntu installation, so I choose to use only the Swap and Root partitions. (As a relative beginner I’m happy to have my mind changed!)

You’ve told Ubuntu setup how to partition your drive, and when you click “Install” those instructions will get executed. First you’ll get a confirmation of the changes. If you’re happy with them, make it so!

Step 5: Your Region & Account Info

The hard part is over, and I hope it went smoothly for you. All that remains is choosing your region and creating a username and strong password. Because I’m lazy, I usually choose to log in automatically.

Choose your location!CANONICAL

Create a username and a strong password. Optionally, choose to log in automatically.CANONICAL

Step 6: Grab A (Small) Cup Of Coffee

Now Ubuntu will start installing and downloading any additional packages if you chose to grab updates. But wait, why a small cup of coffee? Because it’s fast. Really fast. On my Dell XPS 13 with a USB 3.0 stick and an NVMe drive, it took less than 4 minutes. Even on older hardware it’s really snappy.

Step 7: Enjoy Ubuntu

Ubuntu installationCANONICAL

You should be prompted to remove your installation media and reboot. If you had to do the secure boot option, you’ll be taken to that screen and your password will be requested.

For me, the installation process was just a first small step in a longer and much more exciting journey. Hopefully yours is headache free, productive, and fun! Explore the Snap store to install popular apps like Spotify, Skype, Discord and Telegram in a single click, or check out the wealth of open source software available.

Ready to start gaming? Check out my beginner’s guide to updating your graphics drivers and playing Windows-only games on Steam for Linux!

RESOURCES

If you get stuck along the way, here are some resources to get you unstuck.

MORE ABOUT LINUX:

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January 6, 2019January 8, 2019

CentOS Change Password – Linux Hint

Passwords are the oldest and yet, effective form of security measure that almost every single system in the world offers to protect privacy and user data. In the case of CentOS, it’s more important to make sure that everything is secure with a powerful password. However, in cases, passwords need to be changed. There can be a number of reasons, for example, the password being obsolete or disclosed in other security breaches etc. Today, let’s check out the details changing the password on CentOS.

Changing the password

Note that there are 2 different types of passwords – “root” and user(s). If you’re currently within the system, you can easily change the password with a few commands. If not, it will require a bit of a task to change the “root” password and then, the other user(s) password(s).

Change the current user password

Fire up a terminal –

Run the following command –

At first, you have to enter the “root” password. Now, time to enter your new password –

Once changed, you can see the success message.

Changing other user’s password

This is also possible. However, make sure that whatever you’re doing is the right thing. Don’t forget to notify your system admin first!

Enter the user account –

Now, use the “passwd” tool for performing the password change –

Voila! The user now got a new password!

Changing the “root” password

The same technique applies for the “root” user as well. At first, enter the root –

Now, run the command for changing the password –

Voila! Password change successful!

Now, in some cases, you forgot the passwords completely and not able to login into any other users, then the following steps must be followed. Make sure to follow each and every single step PRECISELY. Otherwise, you may ruin the entire system! Restart your system –

When the CentOS icon flashes, hit “e” key on keyboard for entering the grub edit mode.

Scroll down to the line that starts with “linux” or “linux16” –

Now, change the word “ro” with the following line –

Then, press “Ctrl + X” for booting with the configuration.

Now, we need to mount the system so that we can run all the commands as if we were inside the system. Enter the following command –

Time to perform the password change!

The following step is an additional step. Apply this only if your system had SELinux enabled.

Exit the edit mode –

Voila! Your system password is changed! Enjoy!

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January 6, 2019January 8, 2019

How to Filter By IP in Wireshark – Linux Hint

.What is Wireshark?

Wireshark is a networking packet capturing and analyzing tool. It is an open source tool. There are other networking tools but Wireshark is one of the strongest tools among them. Wireshark can be run in Windows, Linux, MAC etc operating system also.

How Wireshark looks like?

Here is the picture of Wireshark version 2.6.3 in Windows10. Wireshark GUI can be changed depending on Wireshark version.

Where to put filter in Wireshark?

Look at the marked place in Wireshark where you can put display filter.

How to put IP addresses Display filter in Wireshark?

There are different ways you can use display IP filter.

Source IP address:

Suppose you are interested in packets from a particular source IP address. So you can use display filter as below.

ip.src == X.X.X.X => ip.src == 192.168.1.199

Then you need to press enter or apply to get the effect of the display filter.

Check the below picture for scenario

Destination IP address :

Suppose you are interested in packets which are destining to a particular IP address. So you can use display filter as below.

ip.dst == X.X.X.X => ip.dst == 192.168.1.199

Then you need to press enter or apply to get the effect of the display filter.

Check the below picture for scenario

Just IP address:

Suppose you are interested in packets which has particular IP address. That IP address is either Source or Destination IP address. So you can use display filter as below.

ip.addr == X.X.X.X => ip.adr == 192.168.1.199

Then you need to press enter or apply [For some older Wireshark version] to get the effect of the display filter.

Check the below picture for scenario

So when you put filter as “ip.addr == 192.168.1.199” then Wireshark will display every packet where Source ip == 192.168.1.199 or Destination ip == 192.168.1.199.

In another way you write filter like below also

ip.src == 192.168.1.199 || ip.dst == 192.168.1.199

See below screenshot for above display filter

Note:

Make sure the display filter background is green when you enter any filter otherwise the filter is invalid.

Here is screenshot of valid filter.

Here is the screenshot for invalid filter.

You can do multiple IP filtering based on logical conditions [ || , && ]

OR condition:

(ip.src == 192.168.1.199 ) || ( ip.dst == 192.168.1.199)

AND condition:

(ip.src == 192.168.1.199) && (ip.dst == 192.168.1.1)

How to put IP addresses capture filter in Wireshark?

Follow below screenshots to put capture filter in Wireshark

Note:

Like display filter capture filter also considered as valid if background is green.
Do remember display filters are different from capture filter in case of syntax.

Follow this link for valid capture filters

https://wiki.wireshark.org/CaptureFilters

What is relation between Capture filter and Display filter?

If capture filter is set and then Wireshark will capture those packets which matches with capture filter.

For example:

Capture filter is set as below and Wireshark is started.

After Wireshark is stopped we can see only packet from or destined 192.168.1.199 in whole capture. Wireshark did not capture any other packet whose source or destination ip is not 192.168.1.199. Now coming to display filter. Once capturing is completed, we can put display filters to filter out the packets we want to see at that movement.

In another way we can say, Suppose we are asked to buy two types of fruits apple and mango. So here capture filter is mangoes and apples. After you got mangoes [different types] and apples [green, red etc] with you, now you want to see only green apples from all apples. So here green apple is display filter. Now if I ask to you show me orange from the fruits, you cannot show as you did not buy oranges. If you would have bought all types of fruits [Means you would have not put any capture filter] you could have shown me oranges

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