C Standards and Implementation In C Language

C is standardized by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) through the ISO/IEC 9899 standard. This standard defines the syntax, data types, and library functions of the C language, and provides a specification for the behavior of conforming C implementations.

The most recent version of the C standard is C11, which was published in 2011, and it added new features such as _Bool type, anonymous structures, and improved Unicode support. The previous version is C99, which was published in 1999 and it included features such as inline functions, variable-length arrays, and complex numbers.

There are several popular C compilers that implement the C standard, including GCC (GNU Compiler Collection), Clang, and Microsoft Visual C++. These compilers are available on a wide range of platforms, including Windows, Linux, and macOS.

Each compiler has its own specific features and extensions that may not be part of the standard, but they are widely used. For example, GCC provides a set of extensions known as GNU C extensions that add additional functionality to the C language, such as variable-length arrays and designated initializers.

It's important to keep in mind that not all compilers fully comply with the C standard, and some may have their own extensions or variations. Therefore, it's recommended to use standard library functions and features to avoid compatibility issues when running the code on different compilers or platforms.

Additionally, it's important to note that the C standard only defines the behavior of the language, not the specific implementation details. Therefore, different compilers may produce slightly different machine code for the same C source code, which can result in slightly different performance characteristics.