Re: dlopen searching application?

From: bd (bdonlan_at_bd-home-comp.no-ip.org)
Date: 04/29/03 

Date: Mon, 28 Apr 2003 19:52:19 -0400

On Mon, 28 Apr 2003 23:29:50 +0000, Fletcher Glenn wrote:

> bd wrote:
>>
>> How can I get dlopen to link functions in the program calling it? E.g, I
>> have a function foo() in the program itself, and at some point the program
>> loads library bar, which needs to call foo(). How can I get dlopen to do
>> this?
>
> Isn't that what dlsym is supposed to do?

You misunderstand - foo() is in the programming calling dlsym(). It's like
this:
--- app.c ---
void foo(){
/* ... */
}

void bar(){
  void *lib;
  void (*quux)();
  lib = dlopen("somelib.so", RTLD_NOW | RTLD_GLOBAL);
  quux = dlsym(lib, "quux");
  quux();
  dlclose(lib);
}
--- end app.c ---

--- somelib.c ---
extern void foo();

void quux(){
  /* ... */
  foo();
  /* ... */
}

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