On 7/13/06, Shriramana Sharma <samjnaa@xxxxxxxxx> wrote:
Often I see apps which are dependent on this .so file or that. I don't know how apps can be written that depend on libraries that are not linked into the executable. So far I have been linking all needed libraries into the executable. A .so is a collection of what? An .a is a collection of .o-s, right? What is a .la? I am so very confused.
An .so file is a shared library, a collection of object files, allowing executables to be linked against at __runtime__. They are called shared objects, because multiple processes can make use of them without keeping a private copy in their process space. Additionally, shared libraries are normaly self contained, which means that they do not contain references that cannot be resolved at runtime. For example, libpng makes use of routines from libz which is loaded at runtime automatically. If both libs were static (.a files, yes, a collection .o files) all programs that depend on those libraries must be linked against them at __compile time__. Shared objects are loaded into memory at runtime on behalf of another shared object ld.so and ld-linux.so for ELF binaries. The .la files are used for linking and versioning by libtool and are created automatically. It is a simple text file that contains some important information for both static and shared libraries. Hope that helped. \Steve - : send the line "unsubscribe linux-c-programming" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
