CHeader

CHeader commonly refers to a C header file, designated by the .h extension, that declares the interfaces to a C module. A C header file serves as the interface for a module and is included by multiple source files to share declarations. It typically contains function prototypes, type definitions (typedefs, structs, enums), macro definitions, inline functions, and sometimes constants. It does not usually contain the full function implementations. The corresponding implementation is placed in a .c source file.

Header files commonly use include guards to avoid multiple inclusion, using patterns like #ifndef FOO_H ... #define FOO_H ... #endif, or the #pragma once directive where supported.

In cross-language projects, header files may include extern "C" blocks to ensure C linkage when compiled with a C++ compiler, preserving symbol names.

Best practices: keep headers lightweight and free of implementation details; minimize dependencies by forward-declaring types when possible and using opaque pointers; place only necessary declarations in the header to reduce compile-time coupling; document interfaces for users and maintainers.

Build and tooling: compilers and build systems locate headers via include paths; tools like doxygen can parse headers to generate API documentation. In some contexts, CHeader may refer to a helper utility or generator that produces header files from metadata, but the standard usage remains the declaration file that defines the public interface of a C module.