History of C

Contents 1 Early C 2 Standard C 2.1 Future development 2.2 See also 2.3 External links

Early C

• 1969: B created, based on BCPL, to replace PDP-7 assembler as the system programming language for Unix

• added operators ++ , -- , compound assignment, remained a typeless language like BCPL

• 1971: NB ("new B") created when porting B to PDP-11

• types ( int , char , arrays and pointers), array-to-pointer conversion, compilation to machine code

• 1972: Language renamed to C

• struct , operators && and || , preprocessor, portable I/O

• 1973: Unix re-written in C

• unsigned , long , union , enumerations, increased type safety

• 1978: The C Programming Language, 1st edition

Standard C

• 1983: ANSI established X3J11 committee
• 1988: The C Programming Language, 2nd edition
• 1989: C89 , the ANSI C standard published

1. codified existing practices
2. new features: volatile , enum , signed , void , locales
3. From C++: const , function prototypes

• 1990: C90 , the ANSI C standard accepted as ISO/IEC 9899:1990
• 1994: Technical corrigendum 1 (ISO/IEC 9899:1990/Cor.1:1994)

• 44 small changes

• 1995: C95 (ISO/IEC 9899:1990/Amd.1:1995) ( online store )

1. greatly expanded wide and multibyte character support ( <wctype.h> , <wchar.h> , additions and changes to stream I/O, etc)
2. digraphs, <iso646.h> ,

• 1996: Technical corrigendum 2 (ISO/IEC 9899:1990/Cor.2:1996)

• 24 small changes

• 1999: C99 (ISO/IEC 9899:1999)

1. new features: bool , long long , <stdint.h> , <inttypes.h> , restrict , compound literals, variable length arrays, flexible array members, designated initializers, <fenv.h> , variadic macros, complex numbers, __func__ , hexadecimal floating-point format ( % a ), monetary formatting in lconv , isblank , concatenation of narrow and wide string literals, trailing comma in enumerations, empty arguments in function-like macros, STDC_ * pragmas, va_copy , null return of tmpnam , null pointer in setvbuf , hh and ll length-specifiers in printf , snprintf , _Exit , <tgmath.h> , POSIX-like strftime specifiers
2. from C++: inline , mix declarations and code, declarations in the init-clause of the for loop, // comments, universal character names in source code
3. removed implicit functions and implicit int

• 2001: Technical corrigendum 1 (ISO/IEC 9899:1999/Cor.1:2001)

• 11 defects fixed

• 2004: Technical corrigendum 2 (ISO/IEC 9899:1999/Cor.2:2004)
• 2004: Unicode TR (ISO/IEC TR 19769:2004) ( ISO store ) ( N1040 November 7, 2003 draft)
• 2007: Technical corrigendum 3 (ISO/IEC 9899:1999/Cor.3:2007) ( N1256 September 7, 2007 draft)

• deprecated gets

• 2007: Bounds-checking interfaces TR (ISO/IEC TR 24731-1:2007) ( ISO store ) ( N1225 March 28, 2007 draft)
• 2008: Embedded TR (ISO/IEC TR 18037:2008) ( ISO store ) ( N1021 September 24, 2003 draft)
• 2009: Decimal floating-point TR (ISO/IEC TR 24732:2009) ( ISO store ) ( N1241 July 5, 2007 draft)
• 2009: Mathematical special functions TR (ISO/IEC TR 24747:2009) ( ISO store ) ( N1182 August 2, 2006 draft)
• 2010: Dynamic allocations functions TR (ISO/IEC TR 24731-2:2010) ( ISO store ) ( N1388 June 1, 2009 draft)
• 2011: C11 (ISO/IEC 9899:2011) ( ISO store ) ( ANSI store ) ( N1570 April 12, 2011 draft)

1. thread-aware memory model, <stdatomic.h> , <threads.h> , type-generic functions, alignas / alignof , noreturn , static_assert , analyzability extensions, extensions to complex and imaginary types, anonymous structures and unions, exclusive file open mode, quick_exit
2. removed gets
3. from Bounds-checking interfaces TR: bounds-checking interfaces,
4. from Unicode TR: char16_t , char32_t , and <uchar.h>

• 2012: Technical corrigendum 1 (ISO/IEC 9899:2011/Cor 1:2012) ( ISO store )

• Fixes DR 411

• 2013: Secure Coding Rules TS (ISO/IEC TS 17961:2013) ( ISO store ) ( N1718 May 30, 2013)
• 2014: FP TS part 1: Binary floating-point arithmetic (ISO/IEC TS 18661-1:2014) ( ISO store ) ( N1778 2013 draft)

1. provides changes to C11 (mostly to Annex F) that cover all basic requirements and some recommendations of IEC 60559:2011 (C11 was built on IEC 60559:1989)

• 2015: FP TS part 2: Decimal floating-point arithmetic (ISO/IEC TS 18661-2:2015) ( ISO store ) ( N1912 2015 draft)

1. provides changes to C11 to support all the requirements, plus some basic recommendations, of IEC 60559:2011 for decimal floating-point arithmetic. This supersedes ISO/IEC TR 24732:2009.

• 2015: FP TS part 3: Interchange and extended types (ISO/IEC TS 18661-3:2015) ( ISO store ) ( N1945 2015 draft)

1. provides changes to C11 to support the recommendations of IEC 60559:2011 for extended floating‐point formats and the interchange formats, both arithmetic and non-arithmetic.

• 2015: FP TS part 4: Supplementary functions (ISO/IEC TS 18661-4:2015) ( ISO store ) ( N1950 2015 draft)

1. provides changes to C11 to support all mathematical operations recommended by IEC 60559:2011, including trigonometry in π units, inverse square root, compounded interest, etc.

• 2016: FP TS part 5: Supplementary attributes (ISO/IEC TS 18661-5:2016) ( ISO store ) ( N2004 2016 draft)

1. provides changes to C11 to support all supplementary attributes (evaluation model, exception handling, reproducibility, etc) recommended by IEC 60559:2011

• 2018: C17 (ISO/IEC 9899:2018) ( ISO Store ) ( Final draft )

Main Article: C17

• 2023 C23 (ISO/IEC 9899:2024). C23 is the current revision of the C standard.

Main Article: C23

Future development

• Parallelism TS (Draft N2017 2016-03-10)
• Transactional Memory TS (Draft N1961 2015-09-23)
• C (Latest draft n3550 2025-05-04)

1. List of issues that were not granted DR status: ( N2556 2020-08-02)

Main Article: C29 ?

Next major C language standard revision

See also

C++ documentation for History of C++

External links

1.	The Development of the C Language by Dennis M. Ritchie
2.	Rationale for the C99 standard