How To prevent Static Cling :)

Static vs Dynamic Linking: The Basics

Static Linking

Static linking means that all required libraries are bundled directly into your executable at compile-time. This makes deployment easier since your program doesn’t rely on external dependencies at runtime.

Pros:

• No missing DLLs or shared libraries—your program has everything it needs!
• Faster load times because no external lookups are needed.
• Less risk of versioning issues since everything is baked in.

Cons:

• Bigger executable sizes (since it contains all the library code).
• More memory usage because each process loads its own copy of the library.
• Updating the library means recompiling everything that depends on it.

Dynamic Linking

Dynamic linking, on the other hand, means that your program relies on shared libraries (.so on Linux, .dll on Windows) that are loaded at runtime.

Pros:

• Smaller executable size.
• Memory savings—multiple programs can share the same library in RAM.
• Libraries can be updated without recompiling dependent applications.

Cons:

• If a required shared library is missing, your program won’t run.
• Version mismatches can lead to runtime crashes.
• Debugging can be a nightmare.

Now that we’ve covered the basics, let’s compare how Windows and Linux handle this.

Windows vs. Linux: The Linker Showdown

Windows: Living with DLLs

Windows relies heavily on DLLs (Dynamic Link Libraries). The big issue here is DLL Hell, which happens when:

• Different applications need different versions of the same DLL.
• A system update replaces a DLL, breaking older programs.
• Multiple copies of the same DLL exist, leading to chaos.

Windows developers have fought back with:

• Side-by-side (SxS) assemblies (basically, “versioned” DLLs).
• Redistributable packages (e.g., the Visual C++ Redistributable).
• Static linking (when you don’t want to deal with DLLs at all).

Linux: Shared Libraries and .so Files

Linux handles shared libraries using .so (Shared Object) files. Instead of dumping them in a system folder like Windows, Linux uses:

• /usr/lib and /usr/local/lib for system-wide libraries.
• LD_LIBRARY_PATH for user-defined locations.
• Versioning with soname (e.g., libmylib.so.1 ensures compatibility).

Linux users still face missing .so issues, but package managers (apt, dnf, etc.) make installing dependencies easier.

DLL Hell vs. Shared Library Chaos

Windows developers suffer from DLL Hell, while Linux users encounter dependency nightmares.

DLL Hell happens when:

• A DLL version change breaks compatibility.
• A missing DLL prevents an app from running.
• Multiple apps need different versions of the same DLL.

Shared Library Chaos happens on Linux when:

• A .so file is missing or outdated.
• The system linker (ld.so) can’t find the correct version.
• A program requires a very specific library version.

Both problems are why static linking is sometimes preferred, even if it makes binaries larger.

How the GPL Ties into All of This

If you think linking is just a technical issue, think again! The GNU General Public License (GPL) has some strong opinions about it.

Static Linking and the GPL

• If you statically link to a GPL-licensed library, your entire program is now considered a derivative work and must also be GPL.
• This means you must release your source code under the GPL.

Dynamic Linking and the GPL

• If you dynamically link to a GPL library, things get a little murky.
• Some argue that since the library is a separate file, your code isn’t a derivative work.
• The LGPL (Lesser GPL) was created to allow dynamic linking without forcing your entire app to be GPL.

How Companies Work Around This

• They use MIT/BSD-licensed alternatives to avoid GPL headaches.
• They provide plugin-based architectures where users can load libraries dynamically.
• They release open-source versions to comply with the GPL but sell commercial versions with different licenses.

This is why some proprietary software avoids GPL libraries entirely—they don’t want to risk their code becoming “infected” by the GPL.

Key Takeaways

References

• Windows DLL Documentation
• Linux Shared Library Docs
• GNU GPL and Linking