Re: Best way of compiling applications to run on older linux distros

[Andrew Haley <aph at redhat dot com>]

Tom Quarendon wrote:
>> So, let me see.  You have a Centos4 machine that you could use to build
>> (indeed, you need such a machine to do the testing) but for some
>> reason you
>> don't want to build on that box as well.
> It's just the way we set our machines up. "as well" here is the key
> phrase. We rather assumed that there would be no "as well". We don't
> build one version of the windows product for windows 200, one for XP,
> one for server 2003, one for Vista etc. We just build one. I'm just
> suprised that this is the way that you have to build things for Linux.

You only have to build one.  That's been explained already.

>>> Your implication is that "properly" means building a version for Centos4
>>> on Centos4, a version for linux distro x on linux distro x etc etc. This
>>> isn't in any way obvious, and isn't how things work for Windows, or
>>> indeed Solaris, AIX, zSeries.
>>
>> I've already explained backwards compatibility and how it works on Linux.
> 
> Well I obvisouly didn't understand it then. Most other systems appear to
> have methods of allowing you to build on newer and run on older. This
> doesn't appear to be the case on linux. If that is so, they fine, we'll
> just build on older.

Excellent.  You don't need also to build on newer.

> Still not clear though the affect that the compiler
> has on this. If I compile on Centos4 with latest gcc 4.3.2, is that
> backward compatible? And if I build on Centos4 how compatible is that
> with SUSE for example?

Sometimes you'll need to install older versions of libstdc++ etc.
Distros often include compat- versions of such libraries.  For example,
Red Hat Enterprise Linux 5 includes compat-libstdc++-296 for old
g++ 2.96 compiled packages.

Andrew.