CODEWITHSUNDEEP
c++winapivisual-c++
Steve Quezadas
Steve Quezadas

Reputation: 744

How does GetModuleHandle work in Visual c++

I am new to c++ and this code always returns NULL even though i know the file exists:

HMODULE hModule = GetModuleHandle(TEXT("C:\\Users\\Steve\\Desktop\\stub.exe"));

Interestingly, if i copy stub.exe to C:\Windows\system32, it finds the module with this code:

HMODULE hModule = GetModuleHandle(TEXT("stub.exe"));

Am i missing something incredibly basic?

Upvotes: 3

Views: 29976

Answers (3)

MSalters
MSalters

Reputation: 179779

You can only call GetModuleHandle(L"C:\\Users\\Steve\\Desktop\\stub.exe"); when you're running C:\Users\Steve\Desktop\stub.exe.

But in general, you don't call GetModuleHandle for your EXE name. Since there's only one EXE per process, you just call GetModuleHandle(0).

Upvotes: 9

Necrolis
Necrolis

Reputation: 26171

Firstly, GetModuleHandle requires that you load the dll into the process before hand.

Windows has specific paths that it uses to search for modules, as well as some switches to force 'safe' dll loading, you may want to look into SetDllDirectory and AddDllDirectory if you wish to expand the locations searched. See this for an explanation of how Windows search for binaries.

Upvotes: 3

Don Reba
Don Reba

Reputation: 14031

Here is a quote from MSDN:

GetModuleHandle Function

Retrieves a module handle for the specified module. The module must have been loaded by the calling process.

This means that you have to load the module with LoadLibrary first. System32 might get special treatment, but you really should not be copying anything there. The folder is strictly for the operating system's usage.

Upvotes: 0

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