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Dennis MacAlistair Ritchie --the father of the c language

Dennis MacAlistair Ritchie (born September 9, 1941) is an American computer scientist notable for his influence on ALTRAN, B, BCPL, C, Multics, and Unix. He received the Turing Award in 1983 and the National Medal of Technology in 1998. Ritchie was the head of Lucent Technologies System Software Research Department when he retired in 2007.

Arrise of c language---1972

The milestones in C's development as a language are listed below: UNIX developed c. 1969 BCPL -- a user friendly OS providing powerful development tools developed from BCPL. Assembler tedious long and error prone. A new language ``B'' a second attempt. c. 1970. A totally new language ``C'' a successor to ``B''. c. 1971 By 1973 UNIX OS almost totally written in ``C''.

Ea rly de velo pme nt s The initial development of C occurred at AT&T Bell Labs between 1969 and 1973; ac cor ding t o R it chi e, the m ost c reat ive pe riod oc cu rred in 19 72 . It was nam ed "C " be cau se m an y o f its fe atur es w ere de rived fr om a n e arli er lan gu age c all ed "B", Th e orig in of C i s cl osel y t ied to the de velo pme nt of t he Uni x o pe rat in g system the C l an gua ge ha d bec om e p ow erfu l e no ug h that mo st of the Un ix ke rnel w as r ew ritten in C. Th is was o ne of the fi rs t ope rat in g system ke rnel s i mpl em ent ed in a lan gu age ot he r t han as semb ly

During the late 1970s and 1980s, versions of C were implemented for a wide variety of mainframe computers, minicomputers, and microcomputers, including the IBM PC, as its popularity began to increase significantly. At the same time, Bjarne Stroustrup and others at Bell Labs began work on adding object-oriented programming language constructs to C, resulting in the language now called C++. In 1983, the American National Standards Institute (ANSI) formed a committee, X3J11, to establish a standard specification of C. In 1989, the standard was ratified as ANSI X3.159-1989 "Programming Language C."

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THIS VERSIONS OF THE LANGUAGE IS OFTEN REFERRED TO AS ANSI C ,STANDARD C,OR C89 In 1990, the ANSI C standard (with a few minor modifications) was adopted by the International Organization for Standardization (ISO) as ISO/IEC 9899:1990. This version is sometimes called C90. Therefore, the terms "C89" and "C90" refer to essentially the same language. One of the aims of the C standardization process was to produce a superset of K&R C, incorporating many of the unofficial features subsequently introduced

C89 is supported by current C compilers, and most C code being written nowadays is based on it Any program written only in Standard C and without any hardware-dependent assumptions will run correctly on any platform with a conforming C implementation, within its resource limits. In cases where code must be compilable by either standard-conforming or K&R C-based compilers the __STDC__ macro can be used to split the code into Standard and K&R sections to take advantage of features available only in Standard C.

C99 is also the name of a C compiler for the Texas Instruments TI-99/4A home computer. Aside from being a C compiler, it is otherwise unrelated After the ANSI standardization process, the C language specification remained relatively static for some time Normative Amendment 1 created a new standard for the C language in 1995 but only to correct some details of the C89 standard and to add more extensive support for international character sets the standard underwent further revision in the late 1990s, leading to the publication of ISO 9899:1999 in 1999. This standard is commonly referred to as "C99." It was adopted as an ANSI standard in May 2000

C99 introduced several new features, many of which had already been implemented as extensions in several compilers inline functions variable declaration no longer restricted to file scope or the start of a compound statement several new data types, including long long int optional extended integer types, an explicit boolean data type, and a complex type to represent complex numbers variable-length arrays support for one-line comments beginning with //, as in BCPL or C++ new library functions such as snprintf new header files, such as stdbool.h and inttypes.h type-generic math functions (tgmath.h) improved support for IEEE floating point designated initializers

C99 is for the most part upwardcompatible with C90, but is stricter in some ways; in particular, a declaration that lacks a type specifier no longer has int implicitly assumed. The C standards committee decided that it was of more value for compilers to diagnose inadvertent omission of the type specifier than to silently process legacy code that relied on implicit int. In practice, compilers are likely to diagnose the omission but also assume int and continue translating the program.

Su pp ort by m ajo r c omp il er s GCC and other C compilers now support many of the new features of C99. However, there has been less support from vendors such as Microsoft and Borland that have mainly focused on C++, since C++ provides similar functionality improvement. GCC, despite its extensive C99 support, is still not a completely compliant implementation; several key features are missing or don't work correctly

C's primary use is for "system programming", including implementing operating systems and embedded system applications C has also been widely used to implement end-user applications, although as applications became larger much of that development shifted to other,higherlevel languages. One consequence of C's wide acceptance and efficiency is that the compilers, libraries, and interpreters of other higher-level languages are often implemented in C. C is used as an intermediate language by some implementations of higher-level languages, which translate the input language to C source code, perhaps along with other object representations The C source code is compiled by a C compiler to produce object code. This approach may be used to gain portability C was designed as a programming language, not as a compiler target language, and is thus less than ideal for use as an intermediate language

Runs the C Language Executor and Macro Executor programs on the PC for operation training and application software debugging ,Debugs at the source level of the C Language executor programs. Machine Signal Simulation ,Programs machine I/O signals with LADDER with ease Reads and writes I/O signals on the simulator from MTB's PC application software via the FOCAS2/Ethernet Can simulate PMC axis control (August 2006)

THE PYRAMID REPRESENTATION SHOW THE VALUE OF C LANGUAGE

Each source file contains declarations and function definitions. Function definitions, in turn, contain declarations and statements Declarations either define new types using keywords such as struct, union, and enum, or assign types to and perhaps reserve storage for new variables, usually by writing the type followed by the variable name Keywords such as char and int specify built-in types. Sections of code are enclosed in braces ({ and }) to limit the scope of declarations and to act as a single statement for control structure As an imperative language, C uses statements to specify actions. The most common statement is an expression statement, consisting of an expression to be evaluated, followed by a semicolon as a side effect of the evaluation, functions may be called and variables may be assigned new values To modify the normal sequential execution of statements, C provides several control-flow statements identified by reserved keywords Structured programming is supported by if(-else) conditional execution and by do-while, while, and for iterative execution (looping).

Nat ion al Med al of Te chn olo gy

On April 27, 1999, Thompson and Ritchie jointly received the 1998 National Medal of Technology from President Bill Clinton for co-inventing the UNIX operating system and the C programming language which together have led to enormous advances in computer hardware, software, and networking systems and stimulated growth of an entire industry, thereby enhancing American leadership in the Information Age

The c language is a middle level language Which is creative nature of programming for Multiple applications,, and it can be used in any Computer platforms,, so that c is is used widely For their structure with keywords play an important Role,, thus c is a important language,, and c is Resembled To the sea of languages