What is C?

C (.c) files contain C source code, the foundation of modern computing. C is the language used to write operating systems (Unix, Linux, Windows kernel), embedded systems, and countless applications. Its influence is seen in C++, C#, Java, JavaScript, and many other languages.

C provides direct hardware access, minimal runtime overhead, and procedural programming. Despite being over 50 years old, C remains essential for systems programming, embedded devices, and performance-critical applications.

Did you know? The C language was originally developed to write the Unix operating system!

History

C was created at Bell Labs by Dennis Ritchie to develop Unix. Its simplicity and power made it the foundation for system software development and influenced countless programming languages.

Key Milestones

  • 1972: C developed by Dennis Ritchie at Bell Labs
  • 1978: "The C Programming Language" book (K&R C)
  • 1989: ANSI C (C89) standard
  • 1999: C99 with improved features
  • 2011: C11 with threads and atomics
  • 2018: C17 bug fixes and clarifications

Key Features

Core Capabilities

  • Low-Level Access: Direct memory manipulation with pointers
  • Procedural Programming: Function-based code organization
  • Minimal Overhead: Runs close to hardware
  • Portability: Platform-independent with compilation
  • Standard Library: stdio, stdlib, string functions
  • Preprocessor: Macros and conditional compilation

Common Use Cases

Operating Systems

Linux kernel, Unix systems

Embedded Systems

Microcontrollers, IoT devices

Databases

SQLite, PostgreSQL core

Device Drivers

Hardware interfaces

Advantages

  • Extremely fast execution
  • Direct hardware control
  • Minimal resource usage
  • Highly portable
  • Mature and stable
  • Industry standard for systems

Disadvantages

  • Manual memory management
  • Buffer overflow vulnerabilities
  • No built-in safety features
  • Steep learning curve
  • Verbose for simple tasks
  • Undefined behavior pitfalls

Technical Information

Format Specifications

Specification Details
File Extension .c
MIME Type text/x-c
Header Files .h
Standard ISO C (C17)
Compilation Native machine code
Paradigm Procedural

Common Tools

  • Compilers: GCC, Clang, MSVC
  • Build Tools: Make, CMake
  • Debuggers: GDB, LLDB