You can collect your own functions together into a library. Most programming packages come with a librarian that manages groups of object modules. Each librarian has its own commands, but the general idea is this: if you want to create a library, make a header file containing the function prototypes for all the functions in your library. Put this header file somewhere in the preprocessor’s search path, either in the local directory (so it can be found by #include "header") or in the include directory (so it can be found by #include <header>). Now take all the object modules and hand them to the librarian along with a name for the finished library (most librarians require a common extension, such as .lib or .a). Place the finished library where the other libraries reside so the linker can find it. When you use your library, you will have to add something to the command line so the linker knows to search the library for the functions you call. You must find all the details in your local manual, since they vary from system to system.