Which format does static library (*.lib) files use

Question

Just now I found that static libraries in *nix systems, in other words *.a libraries are nothing but archives of relocatables(*.o files) in ar fromat.

1. What about static libraries(*.lib files) in windows? Which format are they in?

2. I found an article (archived copy 1, archived copy 2) which explains *.lib file structure. But Where can I find "Official" specifications of *.lib file structure/format?

3. Other than ar.exe of mingw is there any tool from Microsoft which extracts relocatable objects of *.lib & *.a files?

EDIT:

I wonder why I'm unable to get to this question. If there are no official specifications. Then how does the compiler ('linker' to be more correct) writers work with *.LIB files?

Answer 1

I found that *.LIB file uses the ar file format.

Official Specifications: Section 7. "Archive (Library) File Format" of Microsoft Portable Executable and Common Object File Format Specification describes this format.

Answer 2

mingw's ar works just fine on *.lib files - even ones created under VisualStudio.

We've actually used it in the past to pull out parts of a library we needed when it contained some other stuff we couldn't link with (due to conflicts with other libraries). Kinda hacky, but it works.