Linux Blimp

Linux commandline is the best and most powerful thing that fascinates a new user and provides extreme power to experienced users and geeks. For those who work on Server and Production, they are already aware of this fact. It would be interesting to know that Linux console was one of those first features of the kernel that was written by Linus Torvalds way back in the year 1991.

Terminal is a powerful tool that is very reliable as it does not have any movable part. Terminal serves as an intermediate between console and GUI environment. Terminal themselves are GUI application that run on top of a desktop environment. There are a lot of terminal application some of which are Desktop Environment specific and rest are universal. Terminator, Konsole, Gnome-Terminal, Terminology, XFCE terminal, xterm are a few terminal emulators to name.

Last day while surfing web, I came across a terminal namely ‘guake‘ which is a terminal for gnome. Though this is not the first time I have learned about Guake. I’d known this application nearly one year ago but somehow I could not write on this and later it was out of my mind until I heard it again. So finally the article is here. We will be taking you to Guake features, installation on Debian, Ubuntu and Fedora followed by quick testing.

What is Guake?

Guake is a Drop Down Terminal for Gnome Environment. Written from scratch mostly in Python and a little in C this application is released under GPLv2+ and is available for Linux and alike systems. Guake is inspired by a console in computer game Quake which slides down from the top by pressing a specially Key (Default is F12) and then slides-up when the same key is pressed.

Important to mention that Guake is not the first of this kind. Yakuake which stands for Yet Another Kuake, a terminal emulator for KDE Desktop Environment and Tilda which is a GTK+ terminal Emulator are also inspired by the same slide up/down console of computer game Quake.

Features of Guake

1. Lightweight
2. Simple Easy and Elegant
3. Functional
4. Powerful
5. Good Looking
6. Smooth integration of terminal into GUI
7. Appears when you call and disappear once you are done by pressing a predefined hot key
8. Support for hotkeys, tabs, background transparency makes it a brilliant application, must for every Gnome User.
9. Extremely configurable
10. Plenty of color palette included, fixed and recognized
11. Shortcut for transparency level
12. Run a script when Guake starts via Guake Preferences.
13. Able to run on more than one monitor

Guake 0.7.0 was released recently, which brings numerous fixes as well as some new features as discussed above. For complete Guake 0.7.0 changelog and source tarball packages can be found Here.

Installing Guake Terminal in Linux

If you are interested in compiling Guake from source you may download the source from the link above, build it yourself before installing.

However Guake is available to be installed on most of the distributions from repository or by adding an additional repository. Here, we will be installing Guake on Debian, Ubuntu, Linux Mint and Fedora systems.

First get the latest software package list from the repository and then install Guake from the default repository as shown below.

---------------- On Debian, Ubuntu and Linux Mint ----------------
$ sudo apt-get update
$ apt-get install guake

---------------- On Fedora 19 Onwards ----------------
# yum update
# yum install guake

After installation, start the Guake from another terminal as:

$ guake

After starting it, use F12 (Default) to roll down and roll up the terminal on your Gnome Desktop.

Seems very beautiful specially the transparent background. Roll down… Roll up… Roll down… Roll up…. run command. Open another tab run command… Roll up… Roll down…

If your wallpaper or working windows color don’t match you may like to change your wallpaper or reduce the transparency of the Guake terminal color.

Next is to look into Guake Properties to edit settings as per requirements. Run Guake Preferences either by running it from Application Menu or by running the below command.

$ guake --preferences

Scrolling Properties..

Appearance Properties – Here you can modify text and background color as well as tune transparency.

Keyboard Shortcuts – Here you may edit and Modify Toggle key for Guage Visibility (default is F12).

Compatibility Setting – Perhaps you won’t need to edit it.

Conclusion

This Project is not too young and not too old, hence has reached certain level of maturity and is quiet solid and works out of the box. For someone like me who need to switch between GUI and Console very often Guake is a boon. I don’t need to manage an extra window, open and close frequently, use tab among a huge pool of opened applications to find terminal or switch to different workspace to manage terminal now all I need is F12.

I think this is a must tool for any Linux user who makes use of GUI and Console at the same time, equally. I am going to recommend it to anyone who want to work on a system where interaction between GUI and Console is smooth and hassle free.

That’s all for now.

Terminal is one of the most important application in Linux which makes it possible for the end user to communicate to the Linux shell and pass instructions. There are several Terminal-like Application, available either in repository or by third party for most of the Standard Linux Distribution. But this time it is a bit different.

Yeah! We are going to test “Nautilus Terminal”. The name itself tells a lot about itself. The Nautilus is default file browser for GNOME Desktop Environment. Nautilus Terminal is an embedded terminal into the nautilus file browser.

What is Nautilus Terminal?

Nautilus Terminal is a Nautilus file browser embedded terminal, which follows your movement and automatically cd to your current directory. Nautilus Terminal makes it possible to work in command line while navigating in Real GUI.

Features of Nautilus Terminal

1. Completely compatible with Nautilus File Browser.
2. Designed to follow your movement and Instructions within directories.
3. Feature of Hide/Show Terminal in file browser, as required makes it very much useful.
4. Supports Copy and Paste in Terminal.
5. Supports Drag and Drop of files/folders in Terminal.
6. The Embedded Terminal is re-sizeable, as per need.

Install Nautilus Terminal in Linux

Nautilus can be downloaded from the link below. Download the correct package, according to your System architecture.

1. http://projects.flogisoft.com/nautilus-terminal/download/

After Downloading the package which is in the form of *.tar.gz from its official website, as pointed out above, we need to do rest of it, as described below.

$ cd Downloads/ 
$ tar -zxvf nautilus-terminal_1.0_src.tar.gz 
$ cd nautilus-terminal_1.0_src 
# ./install.sh -i

Sample Output

:: Checking the Runtime Dependencies... 

  > Python (>= 2.6)                                                      [ OK ] 
  > PyGObject                                                            [ OK ] 
  > GObject Introspection (and Gtk)                                      [MISS] 
  > VTE                                                                  [MISS] 
  > Nautilus Python (>= 1.0)                                             [MISS] 
  > Nautilus (>= 3.0)                                                    [ OK ] 
E: Some dependencies are missing.

We need to resolve dependencies manually. These dependencies were required to be fixed on my Debian 6.0.9 (Squeeze). This may not be the case with you.

On Ubuntu/Debian/Linux Mint

On an Debian based systems, you can use the official PPA to install nautilus from repository as shown below.

$ sudo add-apt-repository ppa:flozz/flozz
$ sudo apt-get update
$ sudo apt-get install nautilus-terminal

After successful installation of Nautilus Terminal, we are ready to test it but before that it is necessary to restart nautilus as.

$ nautilus -q

Next, start the nautilus terminal using the following command.

$ nautilus

Conclusion

Nautilus Terminal is a wonderful tool, which lets your execution in GUI to be visible in embedded command line and Vice-versa. It is a very nice tool for those newbies who are afraid of Linux command Line and/or Newbie.

That’s all for now.

There are multiple terminal emulators you can find on the Linux platform today, with each of them offering users some remarkable features.

But sometimes, we find it difficult to choose which terminal emulator to work with, depending on our preferences. In this overview, we shall cover one exciting terminal emulator for Linux called Tilix.

Tlix (previously called Terminix – name changed due to a trademark issue) is a tiling terminal emulator that uses GTK+ 3 widget called VTE (Virtual Terminal Emulator). It is developed using GTK 3 with aims of conforming to GNOME HIG (Human Interface Guidelines).

Additionally, this application has been tested on GNOME and Unity desktops, although users have also tested it successfully on various other Linux desktops environments.

Just like the rest of Linux terminal emulators, Tilix comes with some illustrious features and these include:

1. Enables users to layout terminals in any style by splitting them vertically or horizontally
2. Supports drag and drop functionality to re-arrange terminals
3. Supports detaching of terminals from windows using drag and drop
4. Supports input synchronization between terminals, therefore commands typed in one terminal can be reproduced in another
5. Terminal grouping can be saved and loaded from disk
6. Supports transparent backgrounds
7. Allows use of background images
8. Supports automatic profile switches based on hostname and directory
9. Also supports notification for out of view process completion
10. Color schemes stored in files and new files can be created for custom color schemes

How to Install Tilix on Linux Systems

Let us now uncover the steps you can follow to install Tilix on the various Linux distributions, but before we move any further, we have to list the various requirements for Tilix to work on Linux.

Dependencies

To work very well, the application requires the following libraries:

1. GTK 3.14 and above
2. GTK VTE 0.42 and above
3. Dconf
4. GSettings
5. Nautilus-Python for Nautilus integration

If you have all the above requirements on your system, then proceed to install Tilix as follows.

On RHEL/CentOS 7 and Fedora 22-27

First, you need to add the package repository by creating a file /etc/yum.repos.d/tilix.repo using your favorite text editor as follows.

# vi /etc/yum.repos.d/tilix.repo

Then copy and paste the text below into the file above:

[ivoarch-Tilix]
name=Copr repo for Tilix owned by ivoarch
baseurl=https://copr-be.cloud.fedoraproject.org/results/ivoarch/Tilix/epel-7-$basearch/
type=rpm-md
skip_if_unavailable=True
gpgcheck=1
gpgkey=https://copr-be.cloud.fedoraproject.org/results/ivoarch/Tilix/pubkey.gpg
repo_gpgcheck=0
enabled=1
enabled_metadata=1

Save the file and exit.

Then update your system and install Tilix as shown:

---------------- On RHEL/CentOS 7 ---------------- 
# yum update
# yum install tilix

---------------- On Fedora 22-27 ---------------- 
# dnf update
# dnf install tilix

On Ubuntu and Linux Mint

There is no official package repository for Ubuntu/Linux Mint, but you can use WebUpd8 PPA to install it as show.

$ sudo add-apt-repository ppa:webupd8team/terminix
$ sudo apt-get update
$ sudo apt-get install tilix

On Debian, tilix added to official repository and can be installed using command:

$ sudo apt-get install tilix

Alternatively, you can install using source code manually using the commands below:

$ wget -c https://github.com/gnunn1/tilix/releases/download/1.7.7/tilix.zip
$ sudo unzip tilix.zip -d / 
$ sudo glib-compile-schemas /usr/share/glib-2.0/schemas/

OpenSUSE users can install tilix from the default repository and Arch Linux users can install the AUR Tilix package.

# pacman -S tilix

Tilix Screenshot Tour

How to Uninstall or Remove Tilix Terminal

In case you installed it manually and want to remove it, then you can follow the steps below to uninstall it. Download the uninstall.sh from Github repository, make it executable and then run it:

$ wget -c https://github.com/gnunn1/tilix/blob/master/uninstall.sh
$ chmod +x uninstall.sh
$ sudo sh uninstall.sh

A Terminal emulator is a computer program that reproduces a video terminal within some other display structure. In other words the Terminal emulator has an ability to make a dumb machine appear like a client computer networked to the server. The terminal emulator allows an end user to access console as well as its applications such as text user interface and command line interface.

You may find huge number of terminal emulators to choose from this open source world. Some of them offers large range of features while others offers less features. To give a better understanding to the quality of software that are available, we have gathered a list of marvelous terminal emulator for Linux. Each title provides its description and feature along with screenshot of the software with relevant download link.

1. Terminator

Terminator is an advanced and powerful terminal emulator which supports multiple terminals windows. This emulator is fully customizable. You can change the size, colour, give different shapes to the terminal. Its very user friendly and fun to use.

Features of Terminator

1. Customize your profiles and colour schemes, set the size to fit your needs.
2. Use plugins to get even more functionality.
3. Several key-shortcuts are available to speed up common activities.
4. Split the terminal window into several virtual terminals and re-size them as needed.

Terminator Homepage
Download and Installation Instructions

2. Tilda

Tilda is a stylish drop-down terminal based on GTK+. With the help of a single key press you can launch a new or hide Tilda window. However, you can add colors of your choice to change the look of the text and Terminal background.

Features of Tilda

1. Interface with Highly customization option.
2. You can set the transparency level for Tilda window.
3. Excellent built-in colour schemes.

Tilda Homepage

3. Guake

Guake is a python based drop-down terminal created for the GNOME Desktop Environment. It is invoked by pressing a single keystroke, and can make it hidden by pressing same keystroke again. Its design was determined from FPS (First Person Shooter) games such as Quake and one of its main target is be easy to reach.

Guake is very much similar to Yakuaka and Tilda, but it’s an experiment to mix the best of them into a single GTK-based program. Guake has been written in python from scratch using a little piece in C (global hotkeys stuff).

Guake Homepage

4. Yakuake

Yakuake (Yet Another Kuake) is a KDE based drop-down terminal emulator very much similar to Guake terminal emulator in functionality. It’s design was inspired from fps consoles games such as Quake.

Yakuake is basically a KDE application, which can be easily installed on KDE desktop, but if you try to install Yakuake in GNOME desktop, it will prompt you to install huge number of dependency packages.

Yakuake Features

1. Fluently turn down from the top of your screen
2. Tabbed interface
3. Configurable dimensions and animation speed
4. Customizable

Yakuake Homepage

5. ROXTerm

ROXterm is yet another lightweight terminal emulator designed to provide similar features to gnome-terminal. It was originally constructed to have lesser footprints and faster start-up time by not using the Gnome libraries and by using a independent applet to bring the configuration interface (GUI), but over the time it’s role has shifted to bringing a higher range of features for power users.

However, it is more customizable than gnome-terminal and anticipated more at “power” users who make excessive use of terminals. It is easily integrated with GNOME desktop environment and provides features like drag & drop of items into terminal.

ROXTerm Homepage

6. Eterm

Eterm is a lightest color terminal emulator designed as a replacement for xterm. It is developed with a Freedom of Choice ideology, leaving as much power, flexibility, and freedom as workable in the hands of the user.

Eterm Homepage

7. Rxvt

Rxvt stands for extended virtual terminal is a color terminal emulator application for Linux intended as an xterm replacement for power users who don’t need to have a feature such as Tektronix 4014 emulation and toolkit-style configurability.

Rxvt Homepage

8. Wterm

Wterm is a another light weight color terminal emulator based on rxvt project. It includes features such as background images, transparency, reverse transparency and an considerable set or runtime options are accessible resulting in a very high customizable terminal emulator.

Wterm Homepage

9. LXTerminal

LXTerminal is a default VTE-based terminal emulator for LXDE (Lightweight X Desktop Environment) without any unnecessary dependency. The terminal has got some nice features such as.

LXTerminal Features

1. Multiple tabs support
2. Supports common commands like cp, cd, dir, mkdir, mvdir.
3. Feature to hide the menu bar for saving space
4. Change the color scheme.

LXTerminal Homepage

10. Konsole

Konsole is yet another powerful KDE based free terminal emulator was originally created by Lars Doelle.

Konsole Features

1. Multiple Tabbed terminals.
2. Translucent backgrounds.
3. Support for Split-view mode.
4. Directory and SSH bookmarking.
5. Customizable color schemes.
6. Customizable key bindings.
7. Notification alerts about activity in a terminal.
8. Incremental search
9. Support for Dolphin file manager
10. Export of output in plain text or HTML format.

Konsole Homepage

11. TermKit

TermKit is a elegant terminal that aims to construct aspects of the GUI with the command line based application using WebKit rendering engine mostly used in web browsers like Google Chrome and Chromium. TermKit is originally designed for Mac and Windows, but due to TermKit fork by Floby which you can now able to install it under Linux based distributions and experience the power of TermKit.

TermKit Homepage

12. st

st is a simple terminal implementation for X Window.

st Homepage

13. Gnome-Terminal

GNOME terminal is a built-in terminal emulator for GNOME desktop environment developed by Havoc Pennington and others. It allow users to run commands using a real Linux shell while remaining on the on the GNOME environment. GNOME Terminal emulates the xterm terminal emulator and brings a few similar features.

The Gnome terminal supports multiple profiles, where users can able to create multiple profiles for his/her account and can customize configuration options such as fonts, colors, background image, behavior, etc. per account and define a name to each profile. It also supports mouse events, url detection, multiple tabs, etc.

Gnome Terminal

14. Final Term

Final Term is a open source stylish terminal emulator that has some exciting capabilities and handy features into one single beautiful interface. It is still under development, but provides significant features such as Semantic text menus, Smart command completion, GUI terminal controls, Omnipotent keybindings, Color support and many more. The following animated screen grab demonstrates some of their features. Please click on image to view demo.

Final Term

15. Terminology

Terminology is yet another new modern terminal emulator created for the Enlightenment desktop, but also can be used in different desktop environments. It has some awesome unique features, which do not have in any other terminal emulator.

Apart features, terminology offers even more things that you wouldn’t assume from a other terminal emulators, like preview thumbnails of images, videos and documents, it also allows you to see those files directly from Terminology.

You can watch a following demonstrations video created by the Terminology developer (the video quality isn’t clear, but still it’s enough to get the idea about Terminology).

Terminology

16. Xfce4 terminal

Xfce terminal is a lightweight modern and easy to use terminal emulator specially designed for Xfce desktop environment. The latest release of xfce terminal has some new cool features such as search dialog, tab color changer, drop-down console like Guake or Yakuake and many more.

Xfce4 Terminal

17. xterm

The xterm application is a standard terminal emulator for the X Window System. It maintain DEC VT102 and Tektronix 4014 compatible terminals for applications that can’t use the window system directly.

xterm

18. LilyTerm

The LilyTerm is a another less known open source terminal emulator based off of libvte that desire to be fast and lightweight. LilyTerm also include some key features such as:

1. Support for tabbing, coloring and reordering tabs
2. Ability to manage tabs through keybindings
3. Support for background transparency and saturation.
4. Support for user specific profile creation.
5. Several customization options for profiles.
6. Extensive UTF-8 support.

LilyTerm

19. Sakura

The sakura is a another less known Unix style terminal emulator developed for command line purpose as well as text-based terminal programs. Sakura is based on GTK and livte and provides not more advanced features but some customization options such as multiple tab support, custom text color, font and background images, speedy command processing and few more.

Sakura

20. rxvt-unicode

The rxvt-unicode (also known as urxvt) is a yet another highly customizable, lightweight and fast terminal emulator with xft and unicode support was developed by Marc Lehmann. It got some outstanding features such as support for international language via Unicode, the ability to display multiple font types and support for Perl extensions.

rxvt-unicode

eDEX-UI is a geeky, fullscreen, highly configurable and cross-platform desktop application resembling a movie-like futuristic computer interface, that runs on Linux, Windows and MacOS. It creates the illusion of a desktop environment without windows.

It is heavily inspired from DEX-UI and the TRON Legacy movie effects. It uses a number of open-source libraries, frameworks and tools. It was designed and intended to be used on devices with large touchscreens, but it works well on a regular desktop computer or perhaps a tablet PC or laptops with touchscreens.

eDEX-UI runs the shell of your choice in a real terminal, and displays live system information about the CPU, memory, temperature, top processes, and network. By default, eDEX runs bash on Linux, but this is configurable. It also has a file manager, and an onscreen keyboard. It comes with various customization options, including multiple themes that you can load from the interface itself.

Terminator is a terminal emulator released under General Public License and is available for GNU/LinuxPlatform. The application program lets you use multiple splitted and resized terminals, all at once on a single screen similar to tmux terminal multiplexer.

How it is Different

Having multiple Gnome Terminal in one window in a very flexible manner is a plus for Linux nerds.

Who Should use It

Terminator is aimed at those who normally arrange lots of terminals near each other, but don’t want to use a frame based window manager.

What are its Features

1. Automatically logs of all the terminal sessions.
2. Drag and Drop features for text and URLs.
3. Horizontal scrolling is supported.
4. Find, a function to search for any specific text within the terminal.
5. Support for UTF­8.
6. Intelligent Quit – It knows about the running process, if any.
7. Vertical scrolling is convenient.
8. Freedom of use, General Public License.
9. Support for Tab based Browsing.
10. Portal ­ written in Python.
11. Platform – Support for GNU/Linux Platform.

Installation of Terminator Emulator on Linux

On most of the standard Linux Distributions, terminator 0.97 version is available in the repository, and cab be installed using apt or yum.

On RHEL/CentOS/Fedora

First, you need to enable RPMForge repository under your system and then you install Terminator emulator using yum command as shown.

# yum install terminator

On Debian/Ubuntu/Linux Mint

On Debian based distributions, you can easily install using apt-get command as shown.

# apt­-get install terminator

How to use Terminator

Run the “terminator” command in the terminal to use it. Once, you fire the command you will see a screen similar to below.

Terminal Emulator Keyboard Shortcuts

To get the most out of Terminator it is crucial to know the key-bindings to control Terminator. The default shortcut keys that I use most are shown below.

1. Split Terminal Horizontally – Ctrl+Shift+0

1. Split Terminal Vertically – Ctrl+Shift+E

1. Move Parent Dragbar Right – Ctrl+Shift+Right_Arrow_key
2. Move Parent Dragbar Left – Ctrl+Shift+Left_Arrow_key
3. Move Parent Dragbar Up – Ctrl+Shift+Up_Arrow_key
4. Move Parent Dragbar Down – Ctrl+Shift+Down_Arrow_key
5. Hide/Show Scrollbar – Ctrl+Shift+s

Note: Check the hidden scrollbar above, it can again be made visible using the same above key combination.

1. Search for a Keyword – Ctrl+Shift+f
2. Move to Next Terminal – Ctrl+Shift+N or Ctrl+Tab

1. Move to the Above Terminal – Alt+Up_Arrow_Key
2. Move to the Below Terminal – Alt+Down_Arrow_Key
3. Move to the Left Terminal – Alt+Left_Arrow_Key
4. Move to the Right Terminal – Alt+Right_Arrow_Key
5. Copy a text to clipboard – Ctrl+Shift+c
6. Paste a text from Clipboard – Ctrl+Shift+v
7. Close the Current Terminal – Ctrl+Shift+w
8. Quit the Terminator – Ctrl+Shift+q
9. Toggle Between Terminals – Ctrl+Shift+x
10. Open New Tab – Ctrl+Shift+t
11. Move to Next Tab – Ctrl+page_Down
12. Move to Previous Tab – Ctrl+Page_up
13. Increase Font size – Ctrl+(+)
14. Decrease Font Size – Ctrl+(­)
15. Reset Font Size to Original – Ctrl+0
16. Toggle Full Screen Mode – F11
17. Reset Terminal – Ctrl+Shift+R
18. Reset Terminal and Clear Window – Ctrl+Shift+G
19. Remove all the terminal grouping – Super+Shift+t
20. Group all Terminal into one – Super+g

Note: Super is a key with the windows logo right of left CTRL.

Reference Links

https://launchpad.net/terminator

That’s all for now.

We will see what is the use of SciPy library in Python and how it helps us to work with mathematical equations and algorithms in an interactive manner. The good thing about SciPy Python package is that if we want classes or construct web pages, SciPy is fully compatible with the system as a whole and can provide seamless integration.

Once the library is installed, we can import it as:

Finally, as we will be using NumPy as well (It is recommended that for all NumPy operations, we use NumPy directly instead of going through the SciPy package):

 

It is possible that in some cases, we will also like to plot our results for which we will use the Matplotlib library. Perform the following import for that library:

 

I will be using the Anaconda manager for all the examples in this lesson. I will launch a Jupyter Notebook for the same:

Now that we are ready with all the import statements to write some code, let’s start diving into SciPy package with some practical examples.

Working with Polynomial Equations

We will start by looking at simple Polynomial equations. There are two ways with which we can integrate Polynomial functions into our program. We can make use of poly1d class which makes use of coefficients or the roots of a polynomial for initialising a polynomial. Let’s look at an example:

When we run this example, we will see the following output:

Clearly, the polynomial representation of the equation is printed as the output so that the result is pretty easy to understand. We can perform various operations on this polynomial as well, like square it, find its derivative or even solve it for a value of x. Let’s try doing all of these in the next example:

When we run this example, we will see the following output:

Just when I was thinking that this is all we could do with SciPy, I remembered that we can integrate a Polynomial as well. Let’s run a final example with Polynomials:

The integer we pass tells the package how many times to integrate the polynomial:

We can simply pass another integer which tells the package how many times to integrate this polynomial.

Solving Linear Equations

It is even possible to solve linear equations with SciPy and find their roots, if they exist. To solve linear equations, we represent the set of equations as NumPy arrays and their solution as a separate NumPy arrays. Let’s visualise it with an example where we do the same and make use of linalg package to find the roots of the equations, here are the equations we will be solving:

Let’s solve the above equations:

 

When we run the above program, we will see that the dot product equation gives zero result, which means that the roots which the program found were correct:

Fourier Transformations with SciPy

Fourier Transformations helps us to express a function as separate components that make up that function and guides us about the way through which we can recombine those components to get the original function back.

Let’s look at a simple example of Fourier Transformations where we plot the sum of two cosines using the Matplotlib library:

Here, we started by constructing a sample space and cosine equation which we then transformed and plotted. Here is the output of the above program:

This is one of the good example where we see SciPy being used in a complex mathematical equation to visualise things easily.

Vectors and Matrix with SciPy

Now that we know a lot of things which SciPy is capable of, we can be sure that SciPy can also work with Vectors and Matrix. The matrices are an important part of linear algebra as matrices is something we use to represent Vector mappings as well.

Just like we looked at solving linear equations with SciPy, we can represent vectors with np.array() functions. Let’s start by constructing a matrix:

Here is the output of the above snippet:

Whenever we talk about matrices, we always talk about Eigenvalues and Eigenvectors. To put in simple words, Eigenvectors are the vectors which, when multiplied with a matrix, do not change their direction, as opposed to most of the vectors. This means that even when you multiply an Eigenvectors with a matrix, there exists a value (or eigenvalue) which is one of the factor of the multiplication. This means:

In above equation, A is the matrix, λ is the Eigenvalue and x is the Vector. Let’s write a simple code snippet to find the Eigenvalues for a given Vector:

When we run this example, we will see the following output:

Calculating Matrix Determinant

The next operation we will carry out with SciPy is to calculate the determinant of a 2-dimensional matrix. We will reuse the matrix we used in the last code snippet here:

When we run this example, we will see the following output:

Conclusion

In this lesson, we looked at a lot of good examples where SciPy can help us by carrying out complex mathematical computations for us with an easy to use API and packages.

Source

In Hollywood movies, hacking always seems interesting, especially because the whole action is spiced up with fancy desktop environments/backgrounds, rapidly uncontrolled typing (with loud typing noise/keystrokes) and rapid scrolling of command output on colorful terminals.

To make it all seem real, the hackers normally keep on explaining real-world hacking concepts (and mentioning used tools/commands) while breaking into computer systems or networks and the action gets done in a matter of seconds or minutes, which is far different from the practical real-world scenario.

However, if you want to get a feel of hacking in the movies, easily on your Linux console, then you need to install the Hollywood terminal emulator: developed by Canonical’s Dustin Kirkland.

Watch how Hollywood Terminal works:

This terminal emulator produces Hollywood melodrama technobabble in your byobu console. In this article, we will show you how to setup the byubo console and Hollywood movies hackers’ terminal emulator in Ubuntu and it’s derivatives such as Linux Mint, Kubuntu etc.

First, add the appropriate repository to your system software sources, then update the packages’ sources list and finally install the packages as follows:

$ sudo apt-add-repository ppa:hollywood/ppa
$ sudo apt-get update
$ sudo apt-get install byobu hollywood

To launch Hollywood terminal type:

$ hollywood

To stop it, simply press [Ctrl+C] to kill the hollywood script itself, then type exit to quit the byobu console.

To set the number of splits to divide your screen, use the -s flag.

$ hollywood -s 4

You can turn off the theme song, using -q flag like this.

$ hollywood -q

You might also like to read these following related articles on Linux Terminal.

1. Terminator – A Terminal Emulator to Manage Multiple Terminal Windows on Linux
2. Terminix – A New GTK 3 Tiling Terminal Emulator for Linux
3. Shell In A Box – A Web-Based SSH Terminal to Access Remote Linux Servers
4. Nautilus Terminal – An Embedded Terminal for Nautilus File Browser in GNOME
5. Guake – A Drop-Down Terminal for Gnome Desktops
6. GoTTY – Share Your Linux Terminal (TTY) as a Web Application

That’s all. Hope you find this interesting but remember real life hacking is complicated, you need to take time to learn, understand and penetrate operating systems or applications and beyond.

If you know of any similar fancy command line utilities out there, do share with us including any other thoughts about this article

GoTTY is a simple GoLang based command line tool that enables you to share your terminal(TTY) as a web application. It turns command line tools into web applications.

It employs Chrome OS’ terminal emulator (hterm) to execute a JavaScript based terminal on a web browsers. And importantly, GoTTY runs a web socket server that basically transfers output from the TTY to clients and receives input from clients (that is if input from clients is permitted) and forwards it to the TTY.

Read Also: Teleconsole – Share Your Linux Terminal with Your Friends

Its architecture (hterm + web socket idea) was inspired by Wetty program which enables terminal over HTTPand HTTPS.

Prerequisites:

You should have GoLang (Go Programming Language) environment installed in Linux to run GoTTY.

How To Install GoTTY in Linux Systems

If you already have a working GoLang environment, run the go get command below to install it:

# go get github.com/yudai/gotty

The command above will install the GoTTY binary in your GOBIN environment variable, try to check if that is the case:

# ls $GOPATH/bin/

How To Use GoTTY in Linux

To run it, you can use the GOBIN env variable and command auto-completion feature as follows:

# $GOBIN/gotty

Else, run GoTTY or any other Go program without typing the full path to the binary, add your GOBIN variable to PATH in the ~/.profile file using the export command below:

export PATH="$PATH:$GOBIN"

Save the file and close it. Then source the file to effect the changes above:

# source ~/.profile

The general syntax for running GoTTY commands is:

Usage: gotty [options] <Linux command here> [<arguments...>]

Now run GoTTY with any command such as the df command to view system disk partitions space and usage from the web browser:

# gotty df -h

GoTTY will start a web server at port 8080 by default. Then open the URL: http://127.0.0.1:8080/ on your web browser and you will see the running command as if it were running on your terminal:

How To Customize GoTTY in Linux

You can alter default options and your terminal (hterm) in the profile file ~/.gotty, it will load this file by default in case it exists.

This is the main customization file read by gotty commands, so, create it as follows:

# touch ~/.gotty

And set your own valid values for the config options (find all config options here) to customize GoTTY for example:

// Listen at port 9000 by default
port = "9000"

// Enable TSL/SSL by default
enable_tls = true

// hterm preferences
// Smaller font and a little bit bluer background color
preferences {
    font_size = 5,
    background_color = "rgb(16, 16, 32)"
}

Shell In A Box (pronounced as shellinabox) is a web based terminal emulator created by Markus Gutschke. It has built-in web server that runs as a web-based SSH client on a specified port and prompt you a web terminal emulator to access and control your Linux Server SSH Shell remotely using any AJAX/JavaScript and CSSenabled browsers without the need of any additional browser plugins such as FireSSH.

In this tutorial, I describe how to install Shellinabox and access remote SSH terminal using a modern web browser on any machine. Web-based SSH is very useful when you are protected with firewall and only HTTP(s) traffic can get through.

Installing Shellinabox on Linux

By default, Shellinabox tool is included on many Linux distributions through default repositories, including Debian, Ubuntu and Linux Mint.

Make sure that your repository enabled and available to install Shellinabox from the that repository. To check, do a search for Shellinabox with the “apt-cache” command and then install it using “apt-get” command. `

On Debian, Ubuntu and Linux Mint

$ sudo apt-cache search shellinabox
$ sudo apt-get install openssl shellinabox

On RHEL, CentOS and Fedora

On Red Hat based distributions, you need to first have enable EPEL repository and then install it using the following “yum” command. (Fedora users don’t need to enable EPEL, it’s already a part of Fedora project).

# yum install openssl shellinabox

Configuring Shellinabox

By default, shellinaboxd listens on TCP port 4200 on localhost. For security reason, I change this default port to a random (i.e. 6175) to make it difficult for anyone to reach your SSH box. Also, during installation a new self-signed SSL certificate automatically created under “/var/lib/shellinabox” to use HTTPS protocol.

On Debian, Ubuntu and Linux Mint

$ sudo vi /etc/default/shellinabox

# TCP port that shellinboxd's webserver listens on
SHELLINABOX_PORT=6175

# specify the IP address of a destination SSH server
SHELLINABOX_ARGS="--o-beep -s /:SSH:172.16.25.125"

# if you want to restrict access to shellinaboxd from localhost only
SHELLINABOX_ARGS="--o-beep -s /:SSH:172.16.25.125 --localhost-only"

On RHEL, CentOS and Fedora

# vi /etc/sysconfig/shellinaboxd

# TCP port that shellinboxd's webserver listens on
PORT=6175

# specify the IP address of a destination SSH server
OPTS="-s /:SSH:172.16.25.125"

# if you want to restrict access to shellinaboxd from localhost only
OPTS="-s /:SSH:172.16.25.125 --localhost-only"

Starting Shellinabox

Once you’ve done with the configuration, you can start the service by issuing following command.

On Debian, Ubuntu and Linux Mint

$ sudo service shellinaboxd start

On RHEL and CentOS

# service shellinaboxd start

On Fedora

# systemctl enable shellinaboxd.service
# systemctl start shellinaboxd.service

Verify Shellinabox

Now let’s verify whether Shellinabox is running on port 6175 using “netstat” command.

$ sudo netstat -nap | grep shellinabox
or
# netstat -nap | grep shellinabox

tcp        0      0 0.0.0.0:6175            0.0.0.0:*               LISTEN      12274/shellinaboxd

Now open up your web browser, and navigate to https://Your-IP-Adress:6175. You should be able to see a web-based SSH terminal. Login using your username and password and you should be presented with your shell prompt.

You can right-click to use several features and actions, including changing the look and feel of your shell.

Make sure you secure you shellinabox on firewall and open 6175 port for specific IP Address to access your Linux shell remotely.

Reference Links

Shellinabox Homepage