DEV Community: Mehreen Mallick Fiona

Demystifying Linux Architecture: A Beginner's Guide

Mehreen Mallick Fiona — Tue, 20 Feb 2024 18:18:18 +0000

Linux, the operating system that powers many of our devices, is like a well-organized city, with different parts working together to make everything run smoothly. Let's take a closer look at its architecture in simple terms.

The Kernel: Think of the kernel as the mayor of our city. It's in charge of managing all the resources our computer needs, like memory, processing power, and connecting with devices such as printers or keyboards. It ensures that everything works together efficiently.
System Libraries: These are like the city's libraries, full of books and resources that people can use. System libraries provide helpful functions and tools for software developers to create programs without having to worry about the nitty-gritty details of how the computer works. They make it easier for programs to talk to the kernel and save files or connect to the internet.
System Utilities: Just like the services in our city, such as garbage collection or electricity, Linux has utilities that help with everyday tasks. These utilities are like handy tools that allow us to manage files, run programs, or configure computer settings. They come in different shapes and sizes from simple commands we type into a terminal to graphical programs with buttons and menus.

The beauty of Linux architecture lies in its simplicity and flexibility. Because it's open-source, anyone can contribute to improving is just like how citizens can suggest improvements for their city. And because it's modular, meaning it's built-in small, interchangeable parts, Linux can be customized to suit different needs, whether it's running on a powerful server or a tiny smartphone.

In essence, Linux architecture is like a well-designed city with the kernel as its mayor, system libraries as its libraries full of resources and system utilities as its helpful services. Understanding how these parts work together can empower anyone to make the most of Linux and explore its vast possibilities.

GUI vs CLI

Mehreen Mallick Fiona — Fri, 09 Feb 2024 16:15:23 +0000

The operating system relies on someone to communicate with the hardware to execute tasks. And that someone is you. By interacting with the operating system, you can assign tasks to the hardware.

The user communicates with the operating system via an interface. A user interface is a program that allows a user to control the functions of the operating system. We will look at two types of user interfaces: the graphical user interface (GUI) and the command-line interface (CLI). Let's cover these interfaces in more detail.

Graphical User Interface (GUI)

A GUI is a user interface that uses on-screen icons to manage various computer tasks. Most operating systems can be used with a graphical user interface. If you've used a personal computer or a cell phone, you have experienced operating a GUI. Most GUIs include these components: a start menu with program groups, a taskbar for launching programs, and a desktop with icons and shortcuts. All these components help you communicate with the operating system to execute tasks.

Command Line Interface (CLI)

In contrast, the command-line interface (CLI) is a text-based user interface that allows you to interact with your computer through commands. These commands communicate with the operating system and execute tasks like opening programs. The command-line interface is a much different structure than the graphical user interface. When you use the CLI, you'll immediately notice a difference. There are no icons or graphics on the screen. The command-line interface looks similar to lines of code using certain text languages. Let me show you another example:

Diving into C/sea🌊?

Mehreen Mallick Fiona — Mon, 08 Jan 2024 18:56:12 +0000

Programming Language-C

Did you know that Dennis Ritchie created the programming language C in the 1970s? It's still widely used and considered highly influential in programming. Many developers consider C the "mother language" of all modern programming languages.

Let us begin with getting familiar with the datatypes that are dealt in C. There are two types of data types in C.

Image description

Depending on the declaration of a variable in C, there are two types of variables. They are as follows:

Global variable: This variable is assigned outside the main() function of C.
Local variable: This variable is assigned inside the main() function of C.

#include <stdio.h>
int r = 8; // global variable
int main() 
{
 int f =13; //local variable
}

N.B: Every C statement ends with a semicolon ;

You can see that I used "include " in the above code. It's a mandatory header file library that allows us to work with input/output functions like 'printf()' for displaying our desired output.

#include <stdio.h>
int main() {
  printf(" Henlo World");
  return 0;
}

Any code inside main()'s curly bracket is considered the notebook and it will be executed as per instruction. Here "return 0;" ends the main() function.

Arrays

Mehreen Mallick Fiona — Sat, 11 Nov 2023 13:51:57 +0000

An array is one kind of data structure where a collection of the same data type is stored. It has two distinct characteristics. They are:

Element: Each item stored inside the array is called element.
Index: Each location of an element stored inside an array holds a numerical position.

P.S:

First value is always stored in the Oth index.
In the case of a circular array, the first value can be at any index.

Python print() function

Mehreen Mallick Fiona — Mon, 14 Nov 2022 18:59:18 +0000

🖨 Print Function:

print() function is a built-in function of python for displaying value of an expression written inside the parentheses as an output.
When we write a set of code and want to see any text output on the screen, we use the print() function.For example:

💥A cool way to format your print statements:

Way 01:

Way 02:

Python's arithmetic operations and its order of precedence

Mehreen Mallick Fiona — Mon, 14 Nov 2022 16:45:44 +0000

Intro:

Guido van Rossum created 'Python' which is a high-level and object oriented programming language in 1991. With emphasis on code readability, and its syntax allows programmers to express their concepts in fewer lines of code and almost like human readable language.
That's how the journey of learning the language of snake starts!

🔵 Numbers:

There are various data types in Python. Today we will only talk about Numbers and how to do basic math in Python. We know that there are two types of basic numbers in arithmetic. They are as follow:

Integer (int):
Positive or negative whole numbers (without a fractional part).
For example: 10,5000000,-35
Floating-point (float):
Any real numbers with “decimal” points or floating-point representation.
For example: -5.678,190.90

And with either of these numbers you can perform basic arithmetic as you would expect.

🟣Arithmetic Operations:

Addition:

Here, 1 and 1 are operands, and "+" is the operator computing addition.

Multiplication:

Here, 1 and 3 are operands, and "*" is the operator computing multiplication in python. We cannot use "x" or "X" for this command.

Division:

Here, 1 and 2 are operands, and "/" is the operator computing multiplication in python. We cannot use ÷ for this command. Division of numbers always yields a float.

Exponentiation:

Basically it's the power operator. Here, 2 and 4 are operands, and "**" is the operator computing exponents in python.

🟢Now we will introduce to two more exciting arithmetic operations that we will use regularly in Python. i.e. floor division and modulus.

Floor Division:

In this arithmetic operation, the double-backslash operator (//) is the floor division operator.
Floor division of integers results in an integer. If one of the operands is float, then the floor division results in a float.

Here we can see, 7 divided by 5 yields 1.4 . But while using the floor division (//), it basically discards the part after the decimal point and returns a whole number by flooring the value to the nearest integer number. i.e. 1

Modulus:

In this arithmetic operation, the percentage sign (%) is the modulus operator and it basically returns the remainder after division. It works as a brilliant checker for finding odd or even number. **
To check whether the number is odd or even, we have to **mod by 2 and if the remainder yields zero then its a even number. Otherwise, the number is odd.
For example:

We can see that 4 divide by 2 yields quotient 2 and remainder 0. So the number is even.

🟡 Order of Precedence:

After learning all the arithmetic operations, we need to know the order of precedence of them. i.e. PEMDAS

We know that Python executes from top to bottom and reads code from left to right. Now, let us see a compound expression below:

Here, according to PEMDAS, operations in brackets should be carried out first. After that, from left to right we can see that next in line is multiplication and then division. Lastly, addition is done.

That's all for today! Feel free to ask me any question if you don't understand.

Installing Git and Creating a GitHub account

Mehreen Mallick Fiona — Sun, 13 Nov 2022 18:09:20 +0000

What is the purpose of Git and GitHub?

To connect tech-enthusiastic people from all around the world.
To reach out to my past version of myself while coding.
To keep track of individual projects.
To look back at any timeline of the project.
To allow us to host a git repository for an open-source project with everyone.
To know who is working with us on the project and what changes are made by them.

To conclude, GitHub is a portable online portfolio for all.

Installation of Git:

Go to https://git-scm.com/downloads
Depending on your operating system, you can choose to download the link:
After clicking that,
- For Windows users: We can download according to our system type. i.e. 32-bit or 64-bit operating system.

N.B: Just in case, if someone does not know how many bits their operating system is, you can check it by the following steps:

Go to "Settings".
Click on "System". and then look for "About".
After opening "About", we can see Device
Specifications and let us know any information about our
operating system i.e.system type. For example, my system
is:

How to make a GitHub account?:

Go to https://github.com/

Click on "Sign up" and follow the steps as instructed by the website to create a GitHub account.