• Table Of Content

Language Notes

C

Python

Powershell

Version Control

Rust

IA-32 Assembly

IA-64

Socket Programming

Tools of the trade

gdb

Introduction

• In some of the previous modules, we studied about how CPU fetches, decodes and executes instructions. Where do those instructions come from? They need to be written, which is done by something called Programming
• Programming is the act of writing instructions for a computer to instruct it to do something

Different generation of programming languages and their levels

The level here is used to indicate how close they are, to the hardware

First generation (1GL) - Machine language

<aside> 👉 What is this?

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• Our microprocessor only understand direct binary instructions viz. machine language.
• Very efficient and powerful code but extremely difficult to write it.

<aside> 👉 Format of a machine level language instruction

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• Opcode (Operation Code): Instruct the computer what functions are to be performed
• Operands: Instruct the computer where to find/ store data for the desired operation

<aside> 👉 Advantages

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• Instructions are executed ditrectly w/o needing any translation
• Extremely fast

<aside> 👉 Disadvantages

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• The code varies from machine to machine, since it is processor dependent, making it Incredibly difficult to write and work with
• Error prone

Second generation (1GL) - Assembly

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• aka Symbolic Language or Low Level Language
• Since writing machine code was extremely hard, processor dependent and time consuming, Assembly was made. Instead of binary instructions, mnemonics are used
• Not cross-platform, and very specific to the processor family such as Intel has IA-32 and IA-64
• Not directly understood by a processor, and an Assembler is needed to convert Assembly Code into Machine equivalent (the mnemonic to binary mappings are fixed)
• Labels are optional in nature and are used to make the task of addressing easier

label: mov A, B
In this scenario, label will have the value of the address where this instruction is loaded in memory and can be used to refence it.

<aside> 👉 Advantages

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• Relatively easier to understand& use
• Less error prone than directly writing machine language
• Faster (>high level)
• Better control on hardware

<aside> 👉 Disadvantages

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• Architecture Dependent
• Harder to learn
• Slow development time
• Less efficient
• No standardisation

Third generation (1GL) - High level language

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• Since binary shit is difficult to understand, and assembly is still difficult to learn and code in, these high level languages were developed
• Example: C, Java, COBOL, FORTRAN, C++, Perl, SQL, JavaScript etc

<aside> 👉 Disadvantages

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• Less flexible than low level
• All the additional steps increase the execution time of an application

<aside> 👉 Advantages

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• Offers ease of development (easy to read and code in, easy debugging and easy maintenance)
• Machine independent
• Lots of hardware operations managed by the language itself
• No need to know computer architecture in detail

Programming paradigms

Programming paradigms are a way to classify programming languages based on their features and the way several things are done and implemented.

Imperative programming