How do I link libraries correctly (static vs shared)?

Linking libraries in C++ can be a bit tricky, especially when deciding between static and shared libraries. Understanding the differences and how to link them correctly is crucial for successful compilation and execution of your programs.

Static vs Shared Libraries

Static libraries are archives of object files, which are linked into the application at compile time. This means that the resulting executable file contains all the necessary code from the library. This can lead to larger executable sizes but eliminates dependency issues since all required code is included.

Shared libraries, on the other hand, are linked during runtime. They are not included in the executable file, which keeps the executable size smaller and allows multiple programs to share the same library in memory. However, this requires the library to be available on the user's system.

Linking Static Libraries

To link a static library, you typically use the `-l` flag followed by the name of the library (without the `lib` prefix and file extension) and the `-L` flag to point to the directory containing the library. For example:

Linking Shared Libraries

Linking a shared library is similar, but you need to ensure that the shared library is present at runtime. You can link it in the same way as a static library:

Make sure the shared library is in a location specified in your system's library path, or use the `LD_LIBRARY_PATH` environment variable to specify its location before running your program.