in reply to Re^6: Plz suggest what is the problem in the following code?
in thread Plz suggest what is the problem in the following code?

I wouldn't build an .so that has a main defined.

That's like saying that you wouldn't write two classes that exported the same named method.

There is nothing magical about the name:main, and there is absolutely no conflict between having a main in a dynamically linked library and the "main" (if it has one), in the executable that dynamically links to that library.

Indeed, it is easy to demonstrate that any executable (with or without a main of its own), can perfectly safely dynamically link to 2, 3 or 200 .so/.dlls that each export their own routine called "main" (or anything else). Once you have (runtime) loaded the library, you query the address of the "main" routine by name and assign the results to a variable (function pointer). You can easily have an array of function pointers, each initialised with the address of a routine named "main" in each of as many .sos as you care to load, and call them all with no confict whatsoever.

You wouldn't be able to statically link them to the executable, but why would you try?

but the examples do segfault on every *nix box I run...

That I really do not understand, and would appreciate your help in understanding it. (Can anyone else conform this under linux?)

What happens if you rename the "main" routine in the final example to say: "mainx"?

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
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Re^8: Plz suggest what is the problem in the following code?
by derby (Abbot) on Feb 04, 2009 at 13:42 UTC

    Runs fine when I rename main to mainx ... and like I said ... by convention/cargo-cult/angry-monkey I would never write a C shared library that redefined main (or didn't have the convention of prefixed method names) because unlike C++ (name mangling) or Java, the *possiblity* of symbol clashing is too great. Sure, there are ways around that but like I said cargo-cult.

    -derby
[reply]
      I said ... by convention/cargo-cult/angry-monkey I would never write a C shared library that redefined main ... because unlike C++ or Java, the *possiblity* of symbol clashing is too great.

      And as I pointed out, the possibility of symbol clashing is no greater with the name "main" than it is with 'start' or 'new' or any other name.

      So, regardless of whether you would or wouldn't do it--that's your choice--the reasoning for not doing it is bogus! Being proud of cargo-cult doesn't make it more legitimate.

      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]

        Proud? Where did you get that from? Nothing could be farther from the truth. Obviously you've mistaken what I've written (or more than likely I did a poor job of writing) to construe that I would *continue* the practice.

        -derby
[reply]

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