[plug] Moving an older app

[Craig Ringer]

> Hi, I have a dynamicly linked, propriety application that has been
> compiled against RedHat 7.0 that I would dearly like to move to a later
> RedHat.
> 
> Is it possible to copy the 7.0 libs somewhere and get the app to call
> them only?

Yes, but there are other potential issues. The best way is to try it and 
see. You can simply set an LD_LIBRARY_PATH environment variable in a 
wrapper script that calls the app, and that'll ensure it loads the right 
libs first. For example

#!/bin/bash
export LD_LIBRARY_PATH=/usr/local/oldapp/libs
/usr/local/oldapp/bin/oldapp

... try that and see how you go. Naturally, you'll need to find out not 
only which libs the app links to, but which libs they in turn depend on. 
Use "ldd /path/to/library_or_application_file" to get the dependencies 
of an app, and then use ldd on those dependencies until you have 
everything. Some libs may also require additional files in /etc, 
/usr/lib, etc.

Craig Ringer