Hey, Ulrich Drepper has written quite alot about shared libraries. He also did some performance tests uppon that topic. * http://people.redhat.com/drepper/ (look at papers) * http://udrepper.livejournal.com/ think it's better to read his papers first, bet noone will explain it that accuratly here. Markus On 7/14/06, Glynn Clements <glynn@xxxxxxxxxxxxxxxxxx> wrote:
Shriramana Sharma 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? A .so (shared object) is structurally quite similar to a single .o file. The difference is that a .so is meant to be able to be linked at run-time. Linking against a .so file doesn't copy the code/data from the .o file to the executable; it just stores references to the .so file in the executable. The loader (ld-linux.so) will load any shared libraries which the executable requires when the executable is loaded. If it can't find one or more libraries, you get an error when you try to run the executable. > An .a is a collection of .o-s, right? It can be a collection of anything (a .a file is just an archive, similar to a .zip file), but it's usually just a collection of .o files. Linking against a .a file is similar to linking against the individual .o files which it contains, except that only those .o files which supply a required symbol (function, variable) are used. > What is a .la? A .la file is a metadata file created and used by libtool. It contains information (e.g. dependencies) which libtool needs to link against a static library. -- Glynn Clements <glynn@xxxxxxxxxxxxxxxxxx> - : 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
-- Markus Rechberger - : 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
