Question

Is it possible to use shared object files in a portable way like DLLs in Windows??

I’m wondering if there is a way I could provide a compiled library, ready to use, for Linux. As the same way you can compile a DLL in Windows and it can be used on any other Windows (ok, not ANY other, but on most of them it can).

Is that possible in Linux?

EDIT:
I’ve just woke up and read the answers. There are some very good ones.
I’m not trying to hide the source code. I just want to provide an already-compiled-and-ready-to-use library, so users with no experience on compilation dont need to do it themselves.
Hence the idea is to provide a .so file that works on as many different Linuxes as possible.
The library is written in C++, using STL and Boost libraries.

Answer 1

I highly highly recommend using the LSB app / library checker. Its going to tell you quickly if you:

• Are using extensions that aren’t available on some distros
• Introduce bash-isms in your install scripts
• Use syscalls that aren’t available in all recent kernels
• Depend on non-standard libraries (it will tell you what distros lack them)
• And lots, upon lots of other very good checks

You can get more information here as well as download the tool. Its easy to run .. just untar it, run a perl script and point your browser at localhost .. the rest is browser driven.

Using the tool, you can easily get your library / app LSB certified (for both versions) and make the distro packager’s job much easier.

Beyond that, just use something like libtool (or similar) to make sure your library is installed correctly, provide a static object for people who don’t want to link against the DSO (it will take time for your library to appear in most distributions, so writing a portable program, I can’t count on it being present) and comment your public interface well.

For libraries, I find that Doxygen works the best. Documentation is very important, it surely influences my choice of library to use for any given task.

Really, again, check out the app checker, its going to give you portability problem reports that would take a year of having the library out in the wild to obtain otherwise.

Finally, try to make your library easy to drop ‘in tree’, so I don’t have to statically link against it. As I said, it could take a couple of years before it becomes common in most distributions. Its much easier for me to just grab your code, drop it in src/lib and use it, until and if your library is common. And please, please .. give me unit tests, TAP (test anything protocol) is a good and portable way to do that. If I hack your library, I need to know (quickly) if I broke it, especially when modifying it in tree or en situ (if the DSO exists).