Shared Objects and Dynamic Link Libraries

Shared Objects and Dynamic Link Libraries

[Soubhik Bhattacharya]

hi!
i have to ask something which is very trivial to many of you...
what is the basic difference between shared objects and dynamic link
libraries (if there's any)? it'll be highly appreciated if you refer me to
good online documentations for libraries, linkers and binary formats
(relocatable, static, shared, elf, coeff, a.out etc etc).....
regards,
soubhik.

Re: Shared Objects and Dynamic Link Libraries

[Ian Lance Taylor]

Soubhik Bhattacharya <soubhik@cse.iitk.ac.in> writes:

> i have to ask something which is very trivial to many of you...
> what is the basic difference between shared objects and dynamic link
> libraries (if there's any)? it'll be highly appreciated if you refer me to
> good online documentations for libraries, linkers and binary formats
> (relocatable, static, shared, elf, coeff, a.out etc etc).....

Your question is somewhat vague.  I will provide some general
information.

``Shared object'' is a term often used with ELF.  It means the same
thing as ``shared library.''  ``Dynamic link library'' is a term often
used with Windows.  It also means the same thing as ``shared
library.''

There are differences between the ELF and Windows implementations of
shared libraries.  Basically, the Windows implementation is more
primitive: it requires using different source code for references to
global variables, depending upon whether they are referenced in the
main program or in a shared library.  Windows also does not support
overriding a function defined in a shared library from the main
executable.  The only advantage of the Windows approach that I can
think of is that it saves an instruction or two per function call
within a shared library.

I am not aware of any single source for online documentation of
libraries, linkers, and binary formats.

Ian