History of C

< c‎ | language

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
  • structs, operators && and ||, preprocessor, portable I/O
  • 1973: Unix re-written in C
  • unsigned, long, unions, 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
  • 1995: C95 (ISO/IEC 9899 AM1) (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,
  • 1995: Technical corrigendum 1 (ISO/IEC 9899 TCOR1)
  • 1996: Technical corrigendum 2 (ISO/IEC 9899 TCOR2)
  • 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 lengthspecifiers 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(E))
  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)
  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) (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) (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) (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)(2016 draft)
  1. provides changes to C11 to support all supplementary attributes (evaluation model, exception handling, reproducibility, etc) recommended by IEC 60559:2011
Includes the deprecation of ATOMIC_VAR_INIT and the fixes to the following defect reports:
Defect Reports fixed in C17 (54 defects)

Future development

  • Parallelism TS (Draft n2017 2016-03-10)
  • Transactional Memory TS (Draft n1961 2015-09-23)
  • C2x (Draft n2347 2019-03-13)) Next major C language standard revision

See also

References