Skip to content
W3S101

C Overview

C Language - Overview

Section titled “C Language - Overview”

C is a powerful, general-purpose programming language known for its efficiency and control over system resources. It was originally developed by Dennis M. Ritchie at Bell Labs in 1972 to create the UNIX operating system.

The first widely known description of the language was in the book “The C Programming Language” by Brian Kernighan and Dennis Ritchie (often called K&R C), published in 1978. Later, the language was standardized by the American National Standards Institute (ANSI) in 1989 (ANSI C or C89) and subsequently by the International Organization for Standardization (ISO). Several revisions followed, including C99, C11, and C17, each adding new features and refining the language.

Despite its age, C remains highly relevant. The UNIX/Linux operating systems, their core utilities, and countless other foundational software systems are written in C. It’s a popular choice for system programming, embedded systems, performance-critical applications, and developing other programming languages and tools.

  • Relatively simple syntax, making it a good foundation for learning other languages.
  • Provides low-level access to memory via pointers.
  • Produces highly efficient code, often comparable to assembly language.
  • Structured language supporting functions and modular programming.
  • Portable, with compilers available for nearly every hardware platform.

Key Facts about C

Section titled “Key Facts about C”
  • Developed initially for writing the UNIX operating system.
  • Evolved from an earlier language called B.
  • Formalized by ANSI in 1988/1989 (ANSI C / C89) and ISO (ISO/IEC 9899).
  • Subsequent standards include C99, C11, C17, and the upcoming C23.
  • Forms the basis for many other programming languages, including C++, C#, Objective-C, and Java.
  • Widely used in operating systems (Linux, Windows, macOS kernels), embedded systems, databases (like PostgreSQL, MySQL), compilers, interpreters, and high-performance computing.

Why Learn and Use C?

Section titled “Why Learn and Use C?”

C provides a unique combination of performance, control, and portability, making it suitable for a wide range of applications where efficiency is critical:

  • Operating Systems Development (Kernels, Drivers)
  • Embedded Systems Programming (Microcontrollers, IoT devices)
  • Compilers and Interpreters for other languages
  • Database Systems
  • Game Engines and Development
  • High-Performance Scientific Computing
  • Network Protocols and Drivers
  • System Utilities and Tools
  • Cross-platform Libraries and APIs

C Programs

Section titled “C Programs”

A C program consists of code written in one or more text files, typically with the “.c” extension (e.g., hello.c). You can use any plain text editor to write your C code. Popular choices include VS Code, Vim, Emacs, Sublime Text, or even simpler editors like Notepad (Windows) or TextEdit (Mac).

This tutorial assumes you are comfortable using a text editor to create and save files containing source code.