How would you link a program to a DLL?

This is a discussion on How would you link a program to a DLL? within the C++ Programming forums, part of the General Programming Boards category; No, the main difference is that dynamic linking allows you load an unload dlls at any time. It also allows ...

  1. #16
    C++まいる!Cをこわせ! Elysia's Avatar
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    No, the main difference is that dynamic linking allows you load an unload dlls at any time. It also allows you to dynamically specify which dlls to load, as opposed to implicit linking. Dynamic linking will also allow to ignore if a dll fails to load or provide your own custom error messages.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  2. #17
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    Oh I see bithub just called it explicit. However, according to MSDN, it's called implicit linking.
    But even so, the name doesn't really mean that much. It's the first method I mentioned, using a .lib file.
    Where does it say that? By calling LoadLibrary() you are explicitly linking to the DLL file. By using a .lib file with no LoadLibrary() call, you are implicitly linking to the DLL file. I'd like to see where MSDN says otherwise. Especially considering they make it very clear right here.

  3. #18
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    :S This is getting a little confusing. Oh well, would you really need to know the difference when all you're trying to do is link a DLL to a program?

  4. #19
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    http://msdn2.microsoft.com/en-us/library/d14wsce5.aspx
    Implicit linking is using a .lib file. Explicit linking, aka dynamic linking, is using LoadLibrary and GetProcAddress.

    Quote Originally Posted by PЯO View Post
    :S This is getting a little confusing. Oh well, would you really need to know the difference when all you're trying to do is link a DLL to a program?
    You should. But most times you only need to use implicit linking (.lib file).
    Dynamic linking might be useful if you need to, for example, load all dlls in a certain directory (for example, plugins).

    Well, actually, the link states that there are two methods:
    Implicit linking (also known as static linking or load-time linking)
    and
    Explicit linking (also known as dynamic linking).
    Last edited by Elysia; 02-09-2008 at 03:37 PM.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  5. #20
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    Talking

    Quote Originally Posted by Elysia View Post
    http://msdn2.microsoft.com/en-us/library/d14wsce5.aspx
    Implicit linking is using a .lib file. Explicit linking, aka dynamic linking, is using LoadLibrary and GetProcAddress.


    You should. But most times you only need to use implicit linking (.lib file).
    Dynamic linking might be useful if you need to, for example, load all dlls in a certain directory (for example, plugins).
    When you are doing implicit linking, what is the .lib file needed for?

  6. #21
    C++まいる!Cをこわせ! Elysia's Avatar
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    It does an automatic GetProcAddress for you, to put it simply. So the function calls are made correctly.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  7. #22
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    Do the .lib files come with the compiler? Because I think I know what you're talking about.

  8. #23
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    Yes, they typically do for dll files for the C++ standard libraries (and C too).
    You'll also find them in SDKs such as Windows SDK to link statically with Windows DLLs (such as winmm.dll).
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  9. #24
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    Well, actually, the link states that there are two methods:
    Implicit linking (also known as static linking or load-time linking)
    and
    Explicit linking (also known as dynamic linking).
    No, they are sometimes called static or dynamic loading. Once again, if it is a DLL file then it is always dynamic linking.

  10. #25
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    Quote Originally Posted by bithub View Post
    No, they are sometimes called static or dynamic loading. Once again, if it is a DLL file then it is always dynamic linking.
    Implicit linking is sometimes referred to as static load or load-time dynamic linking. Explicit linking is sometimes referred to as dynamic load or run-time dynamic linking.
    Where does it say that it's always dynamic linking when it's dlls? Your link certainly doesn't mention.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  11. #26
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    Where does it say that it's always dynamic linking when it's dlls? Your link certainly doesn't mention.
    It's always a dynamic link with DLL files because the link is always done at runtime. A static link is done at compile time (these are done with .a files, not .dll files). Hense the name Dynamic Link Library.

  12. #27
    CSharpener vart's Avatar
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    There is such method as delay-load dlls

    you link dll using lib-file,
    you do not need to use LoadLibrary and GetProcAddress functions
    but you can check if the library is available - and if not - your application still can be loaded without showing this nice windows message "File not found" and work successfully, just not calling any function from dll
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

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    Can someone give me an example of both the DLL, and the program itself? Thank you.
    Hand over your source code, and nobody gets hurt.

  14. #29
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    Why don't you do the DLL and ask for help in making the application use it, if you can't figure it out yourself?
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

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