Re: build configuration help

[John Calcote]

Bob Rossi wrote:
> Will it only work if I install with the default installation directory? 
> What if I change the --prefix=/home/bob/foo. Will /home/bob/foo/bin/bar
> be able to find /home/bob/foo/lib/wxwidgets.so ?
>   
If you install libraries into a "non-standard" location, you're going to 
have the same problems on Unix that you do on Windows. Windows has one 
additional option for finding libraries in non-standard places - it 
always looks in the same directory as the executable first for a DLL. 
You can BUILD an application to install and run from a specific location 
- that is, if you use a -R<libdir> option on your app's linker command 
line, the system will look for libraries in that location, as well as 
the system locations.

The way you implement this is to use $(prefix)/lib, or $(libdir) in your 
-R option, which will resolve to the configured library installation 
directory - /home/bob/foo/lib. When you use -R like this, however, just 
realize that this binary can only be installed on this one non-standard 
location (it can still be installed in standard locations).

The difference between windows and linux in this case, is that windows 
allows you to run your binary from anywhere, and find the library in the 
same relative location (the same directory, in fact). Linux doesn't 
allow this because...can you guess? It's a security risk. Microsoft's 
taken a lot of heat for this over the years.
> OK, I didn't know this. That's awesome. Is this something that I can
> count on being portable? Meaning, will it work on all the unix systems
> you know about, or is it only a feature of gnu ld?
>   
This is fairly standard Unix fare.

John