Dynamic libraries

[Unregistered]

I am totally confused about the whole dynamic libraries concept. could someone give a brief description of what they are and why they are used, or point me in the right direction (google was giving nothing away).

most of all though; as I understand it, dynamic libraries are ones that are 'called' at runtime (?). How does the program locate the mentioned DL ???

any help appreciated

gaz

[Prelude]

>How does the program locate the mentioned DL ???
The executable contains filenames that the loader uses to find the libraries at runtime. This is good because it makes the executable considerably smaller than statically linked programs, where the executable contains complete copies of the libraries. One can also create several executables that link to the same libraries, so it's not as wasteful there either.

-Prelude

[Fordy]

>>How does the program locate the mentioned DL ???

There is a predefined search method (with windows anyway)....

It goes somthing like;

[list=1][*]The directory from which the application loaded. [*]The current directory for the process[*]The system directory (\windows\system or \windows\system32 depending on OS)[*]The windows directory[*]Whatever you have listed in the PATH environment [/list=1]

You can also load the dlls at runtime afer execution of your code has started.....with this you can also specify alternate locations.

[Unregistered]

Great - that search order is what I am looking for: does anyone know the search order for *nix?
I take it that it is similar but with /usr/lib rather than winnt/system32??

cheers

[lliero]

i want to add on what prelude said,,


dll - are dynamic libraries..

we have in process dll and outprocess dll

in process dll are dll that executes within a process

while outprocesss dll, obviously execute outside the process..

so what are these things?

in an in processDll
when an application crashes it crashes the dll too
together with those other application with it..

in an outprocess
when an application crashes it does not crahes the
dll..


i hope i contributed something