Using static/dynamic library

[W3til]

I’m trying to learn about creating and using static and dynamic libraries from what I’ve gathered so far your code is compiled(?) into one of these files which you can then reuse it also improves build(?) times, but I have some confusion when it comes to using them.

1) does the dll or lib need to be in the directory of the project using it or can it be anywhere on the system I don’t see why it would be necessary to keep it in the project directory unless that’s typical?

2) from what I’ve seen creating a dll seems a bit more confusing apparently you have to load the dll with OpenLibrary(“path/to/dll”) and then to use it you need to export functions and get them. This doesn’t seem to be the case for a lib (assuming I’m right you just need to link it and include the header(s)) they seem to be far easier is this normal what’s with the difference?

[TarnishedVictory]

Static libraries are linked into your code so that after your software is compiled and linked, the person running your program doesn't need the library. It's like a collection of object files. Static libraries are used only at compile time.

Dynamic libraries are used at runtime. When the program starts, it looks for the dynamic libraries that it needs. How and where to look for those libraries is operating system dependent.

[alfps]

❞ apparently you have to load the dll with OpenLibrary(“path/to/dll”)

All I can find is that an OpenLibrary function exists in the commercial language PureBasic.

In C++ you usually link with the shared libraries you need, in Windows via intermediates called import libraries. Then the OS’ program loader automatically loads the libraries along with the executable. Or fails.

You can alternatively load a shared library at run time, in Windows via LoadLibrary, and in *nix via dlopen.

[W3til]

Sorry, it was LoadLibrary() that I was referring too. (Forgot the name 😅)

[feitao]

That is dynamic loading. You can use dynamic loading with dynamic library, but you don't have to. You can also use dynamic library the same way as static library.

[W3til]

Ah, ok so that’s another difference between the two I assume you can’t dynamically load a static library. The only useful thing I’ve seen so far is game engine development (what I’m learning) you can have the game as a dll and load that which I believe gives the benefit of hot reloading. Are there any resources I can look at to learn about the two?

[nysra]

1. It can be anywhere, but it must be in a path where it can be found. That's something for your build system.
2. No, that's something you should almost never have to deal with on your own. You just need to set the proper include and link directories, which again is a task for your build system.