History of C

 

C

Language

Standard Library

Type support

Dynamic memory management

Error handling

Program utilities

Date and time utilities

Strings library

Algorithms

Numerics

Input/output support

Localization support

Thread support (C11)

Atomic operations (C11)

 

C language

General topics
Preprocessor
Comments
Keywords
Escape sequences
History of C
Flow control
Conditional execution statements
if statement	switch statement
Iteration statements
for loop	while loop do-while loop
Jump statements
continue statement break statement	goto statement return statement
Functions
function declaration
inline specifier
Types
fundamental types pointer types compound types enumeration types	union types function types
Specifiers
cv specifiers
storage-class specifiers
alignas specifier (C99)
function specifiers (C99)
Literals
integer literals character literals floating-point literals	string literals boolean literals(C99)
Expressions
order of evaluation
operators
operator precedence
alternative operators
Utilities
typedef declaration
attributes (C99)
casts
Miscellaneous
Inline assembly

 

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
3. From C++: const, function prototypes

• 1990: the ANSI standard accepted as ISO/IEC 9899-1990
• 1995: C95 (ISO/IEC 9899 AM1)

1. multibyte character support (wchar_t and all wide and multibyte character functions, wchar.h, wctype.h, and those added to existing headers and corresponding changes to stream I/O, etc)
2. digraphs, iso646.h,

• 1995: Technical corrigendum 1 (ISO/IEC 9899 TCOR1)

• 44 small changes

• 1996: Technical corrigendum 2 (ISO/IEC 9899 TCOR2)

• 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 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))

• 11 defects fixed

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

• deprecated gets

• 2007: Bounds-checking interfaces TR (ISO/IEC TR 24731-1:2007)
• 2009: Decimal floating-point TR (ISO/IEC TR 24732:2009)
• 2010: Dynamic allocations functions TR (ISO/IEC TR 24731-2:2010)
• 2011: C11 (ISO/IEC 9899:2011) (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)

• 2 minor bug fixes

• 2013: Secure Coding Rules TS (ISO/IEC TS 17961:2013) (2012 draft)

Future development

• Floating-point extensions TS (ISO/IEC TS 18661, supersedes ISO/IEC TR 24732:2009). 2013/2014 drafts:

• part 1 (final)
• part 2 (final)
• part 3 (PDTS)
• part 4 (PDTS)
• part 5

References

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