History of C Language

Before C: The Need for a Better Language

In the 1960s, computers were large, expensive, and programmed using low-level languages. Two languages influenced C heavily:

• BCPL (Basic Combined Programming Language) – Created by Martin Richards
• B Language – Created by Ken Thompson at Bell Labs

BCPL → B → C This evolution added better syntax, data types, and features suitable for system-level programming.

Timeline of C Language Evolution

• 1967 – BCPL developed by Martin Richards. Used for system software.
• 1969 – B Language created by Ken Thompson for early UNIX systems.
• 1972 – C Language created by Dennis Ritchie at Bell Labs.
• 1973 – UNIX rewritten in C, proving C's power for system-level coding.
• 1978 – K&R C: The first famous C book “The C Programming Language” by Kernighan & Ritchie.
• 1989 – ANSI Standardization (C89), the official standardized version of C.
• 1990 – ISO Standard (C90) adopted internationally.
• 1999 – C99: Introduced inline functions, long long int, variable-length arrays.
• 2011 – C11: Added multi-threading, atomic operations, Unicode support.
• 2018 – C18: Bug fixes and improved stability.

Why Was C Created?

• Needed a language to write the UNIX operating system
• Wanted portability → code should run on many machines
• Balance between high-level and low-level power
• Needed better control of hardware
• Wanted a simple, efficient, and flexible language

C’s Role in Developing UNIX

Originally, UNIX was written in assembly language. This made it difficult to modify or port to new hardware.

Today, C is still used in:

• Linux Kernel
• Windows core components
• Android OS
• MacOS + iOS low-level code

C’s Influence on Modern Languages

C inspired or formed the base structure of many major languages:

• C++ → direct extension of C
• Java → borrowed syntax and structure
• JavaScript → C-style syntax
• Python → C-based implementation (CPython)
• Go → C-like syntax and memory model
• Rust → low-level control similar to C

Why C is Still Popular?

• Fastest execution among high-level languages
• Used in embedded systems & hardware programming
• Powerful pointer and memory management
• Foundation for OS, compilers, interpreters
• Portable across platforms
• Simple syntax but powerful features

Summary of C's Evolution

BCPL (1967)
   ↓
B (1969)
   ↓
C (1972)
   ↓
K&R C (1978)
   ↓
ANSI C / C89 (1989)
   ↓
ISO C90 (1990)
   ↓
C99 (1999)
   ↓
C11 (2011)
   ↓
C18 (2018)

Practice Questions

1. Who developed C language and why?
2. Explain the relationship between BCPL, B, and C.
3. What changes did ANSI C introduce?
4. Why was UNIX rewritten in C?
5. List at least 5 modern languages influenced by C.

Practice Task