32 and 64 bit RPM contents

[Maryyy]

I installed 64bit Linux for the first time, so my question can be quite silly.
After some struggle with nvidia installer and 32bit apps, and 32bit apps in general I noticed one thing. Same packages, but for different arch can actually contain identical files in identical locations.

Small example:

rpm -qa SDL_net-devel
SDL_net-devel-1.2.7-4.fc9.i386
SDL_net-devel-1.2.7-4.fc9.x86_64


rpm -ql SDL_net-devel-1.2.7-4.fc9.x86_64
/usr/include/SDL
/usr/include/SDL/SDL_net.h
/usr/lib64/libSDL_net.so

rpm -ql SDL_net-devel-1.2.7-4.fc9.i386
/usr/include/SDL
/usr/include/SDL/SDL_net.h
/usr/lib/libSDL_net.so

In this case SDL_net.h is the same in both cases. But there are many other examples of this.
Also, I noticed, that if I e.g. uninstall x86_64 arch package and leave the i386 one and then do rpm -ql name.i386.rpm, it shows files which are not available on the system anymore, because they were removed with the x86_64 rpm.

It's likely normal behaviour and I'm probably overlooking something obvious, but it's bugging me.

Thx in advance for enlightening.

[Firewing1]

The .h files are header includes, so unlike binaries they don't vary from i386 to x86_64. So in this case, it's safe for both packages to own them.

Although I don't think that removing the x86_64 RPM should also remove the header files if the i386 version is still installed.

[stevea]

Ehhh not so fast. A *lot* of the standard /usr/include .h files vary between 32 & 64.
You just haven't looked if you think otherwise. Pull glibc-headers for the two and
compare for example.

If a package is truly arch independent it will carry a 'noarch' suffix.
*Some, even many if the includes are common, but quite a few differ.

[Firewing1]

glibc is a core system package though, it's a bit different... On the application level, it's very common for two arches to share the same headers.