.a Files.

[Netaro]

So, i was looking through the c++ standart header, and the thing i've noticed, those only contain the declarations of functions. Ok, but where are the definitions? For example, i wanted to see what's "inside" the system() function, how it works etc, etc... So, i noticed those .a files. So, two questions i'd like to ask: What are .a files, what they contain, and where are the "insides" of those std functions?

[JosAH]

So, i was looking through the c++ standart header, and the thing i've noticed, those only contain the declarations of functions. Ok, but where are the definitions? For example, i wanted to see what's "inside" the system() function, how it works etc, etc... So, i noticed those .a files. So, two questions i'd like to ask: What are .a files, what they contain, and where are the "insides" of those std functions?

The source code of the definitions is most likely not there unless you've downloaded
the sources. The .h files simply declare the existence of functions, externals,
classes etc. The .a files (.a == archive) are static libraries that contain the compiled
versions of the definitions of all those functions, classes etc.

kind regards,

Jos

[Cucumber]

Just to complement a little.

In the Windows world, static libraries usually are named as ".lib" files. For instance, when I programmed un TurboC, there were a bunch of lib files that were automatically linked with my programs by the IDE.

(By the way, that is one of the advantages of using an IDE, IDEs will link your programs using a basic set of libraries so they can run in the operating system you are working with. If IDEs didnt exist, we would be using makefiles or worst, we would be compiling by hand file by file and the linking all of them together.)

GNU compilers that run on Windows use the same name format that is used in Unix machines, where the static libraries are identified as .a files. That is why users of mingw or any other GNU compiler for windows will see .a files rather than .lib files.

As a final note, I think the most basic static lib that is always linked with MSDOS and WIndows programs is the CRT lib, but Im not sure. CRT stands for C Run Time, which means that library contains all the precompiled C language standard functions like sprintf, sscanf etc.