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Message-ID: <3C61ED02.3060204@watsen.net>
Date: Wed, 06 Feb 2002 18:57:06 -0800
From: Kent Watsen <kent AT watsen DOT net>
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To: cygwin AT cygwin DOT com
Subject: Re: dlopen(0, RTLD_LAZY) doesn't work?
References: <3C61E3C1 DOT 9010200 AT watsen DOT net>
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OK, so I've written the windows equivalent of my original program
and still get the same error - is there some linking option I'm missine?

Here is the new code, again just compile (gcc foo.c) and run (foo.exe):

#include <stdio.h>
#include <windows.h>

extern __declspec(dllexport) void foo(void)
{
    printf("hello\n");
}

int main(int argc, char *argv[])
{
    void* dl   = NULL;
    void* func = NULL;

    dl = (void *) GetModuleHandle (NULL);
    if (dl == NULL) {
        printf("GetModuleHandle() failed\n");
        exit(0);
    }

    func = (void*)GetProcAddress((HMODULE)dl, "foo");
    if (func == NULL) {
        printf("GetProcAddress() failed (code %u)\n", GetLastError());
        exit(0);
    }

    printf("do something meaningful\n");

    return 0;
}









Kent Watsen wrote:

>
> Hi,
>
> I've read the mailing list archives and searched google trying
> to figure out how to get the following program to work.  All
> you have to do is save it to a file (foo.c), compile (gcc foo.c),
> and run - I always get "dlsym() failed."
>
> Note, I have tried many variations of extern and _declspec
> as well as looking for "_foo" in addition to "foo" ("nm a.exe |
> grep foo" returned "0040104c T _foo"...
>
> Here is the code - help would be greatly appreciated - thanks!
>
> #include <stdio.h>
> #include <dlfcn.h>
> #include <windows.h>
>
> extern __declspec(dllexport) void foo(void)
> {
>    printf("hello\n");
> }
>
> int main(int argc, char *argv[])
> {
>    void* dl    = NULL;
>    void* func = NULL;
>
>    dl = dlopen(0 , RTLD_LAZY);
>    if (dl == NULL) {
>        printf("dlopen() failed\n");
>        exit(0);
>    }
>
>    func = dlsym(dl, "foo");
>    if (func == NULL) {
>        printf("dlsym() failed\n");
>        exit(0);
>    }
>
>    printf("do something meaningful\n");
>
>    dlclose(dl);
>    return 0;
> }
>
>
>
>
> -- 
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