What is included?

included is a term often used in programming and configuration files, particularly in contexts like:

• Configuration Files: Many configuration systems (like those for web servers, build tools, and linters) allow you to break down large configuration files into smaller, more manageable pieces. The included directive is used to specify that the contents of another file should be treated as if they were directly inserted into the current file at the point where the included statement appears. This promotes modularity and reusability. For example, instead of repeating common settings across multiple project configuration files, you could define them in a separate file and then include that file in each project.
• Programming Languages (Specifically Preprocessing): Some languages, like C and C++, use a preprocessor that handles directives like #include. When the preprocessor encounters #include "my_header.h", it essentially copies the contents of my_header.h into the current source file before compilation. This is a form of including. These are often used to include header files that declare functions, structures, and variables used in the program.
• Build Systems: Build systems (like Make, CMake, or Gradle) often have mechanisms for including other build scripts or configuration files. This allows you to reuse common build logic across multiple projects or modules. You might, for example, include a file that defines common compiler flags or library dependencies.

Key benefits of using included files:

• Modularity: Breaks down large files into smaller, more manageable units.
• Reusability: Allows you to reuse common configurations or code across multiple projects.
• Organization: Improves the overall structure and readability of your project.
• Maintainability: Changes to common settings only need to be made in one place, reducing the risk of errors.

Important Considerations:

• Circular Dependencies: Be careful to avoid circular include dependencies, where file A includes file B, which includes file A (either directly or indirectly). This can lead to errors or infinite loops during preprocessing or configuration loading.
• Order of Inclusion: The order in which files are included can sometimes be important, as later inclusions can potentially override settings or definitions from earlier inclusions.
• Scope: Understand the scope of variables and definitions within included files. In some cases, they might be local to the included file, while in other cases, they might be global.

The specific syntax and semantics of include vary depending on the programming language, build system, or configuration tool being used. Consult the documentation for your specific tool for details. The concept of modularity is closely related to using includes effectively.