NOTE: These notes are very random and These are some concept but are not in detail and explained enough , so it’s best to treat them as concepts to research on , so do your on deep dive into each of the concepts using Google, Youtube and AI

Created by Salman Al Qureshi Linkedin: Salman Qureshi

http://www.linkedin.com/in/salman-qureshi-4aa41a247

Linux Deep Dive

• linux is made by linus benedict tornvalds, first version was released in 1991 on the internet
• Shell in linux means a program that serves as a interface between the user and the computer OS . there are many linux shell types like bash, zsh, cshell, sh shell etc .
• linux file system is how linux stores files and folders and how it manages them

• Interpreted languages takes the code and then an interpreter program reads the source code line by line, translates it to a format the computer understands, and executes it immediately., This process happens each time the code is executed that’s why these code needs an interpreter to be executed . Because of the on-the-fly translation, interpreted code can be slower than compiled code.
• Compiled languages in these languages the program is converted into machine code and then saved in a file as an executable, This conversion happens once and this process is called compiling, once this process is done, the code can be sent to others without any need for compiler
• Scripting involves writing scripts or small programs to automate tasks or manipulate existing systems. It is characterized by its focus on rapid development and ease of use. Scripting languages such as Python, Perl, and JavaScript are commonly used for tasks like system administration, web development, and automation. Scripts are typically executed line by line by an interpreter without the need for compilation, allowing for quick testing and modification. The scripting development process often emphasizes rapid prototyping and iterative development, enabling developers to solve specific problems efficiently. Overall, scripting provides a flexible and efficient approach to automating tasks and simplifying complex operations.
• Programming encompasses a broader range of activities, including designing, implementing, and maintaining software systems. Unlike scripting, programming involves a more structured approach to software development. Programming languages such as C, C++, Java, and C# offer extensive control over system resources and performance optimization. Programs are typically compiled into machine code or bytecode before execution, which can provide better performance but may require additional steps in the development process. The programming development process involves various stages, including requirements analysis, design, testing, debugging, and maintenance. While scripting focuses on smaller, specialized tasks, programming addresses a wider range of software development needs, from applications and games to operating systems and databases.

RHEL:

• In linux almost commands are developed in C language & then converted in binary. In windows we call it exe & in linux we call it binary.In windows we call it restart & in linux we call it reboot. Windows have registry & in linux no registry but FS hierarchy. Windows have defrag & in linux no defrag because of the way how files are written. So anyways commands are atlast binary file which are kept in some path[location] from where we call them & run it as a command.