C language

The C language was developed on the UNIX operating system, and is used to code the operating system kernel. Most UNIX application programs are also written in C. However, the operating system supports many programming languages, and C compilers are available on many different operating systems.

``C language compilers'' provides a complete reference guide to the C language. Here are some features of the language:

• Basic data types-- characters, integers of various sizes, and floating point numbers;

• Derived data types-- functions, arrays, pointers, structures, and unions;

• A rich set of operators, including bit-wise operators;

• Flow of control-- if, if-else, switch, while, do-while, and for statements.

Application programs written in C usually can be transported to other machines without difficulty. Programs written in ANSI standard C (conforming to standards set down by the American National Standards Institute) have an even higher degree of portability.

Programs that require direct interaction with the operating system kernel for low-level I/O, memory management, and interprocess communication, can be written efficiently in C using the calls to system functions contained in the standard C library. See cpio(C), umask(C) and stat(S) for more information.