== RPM tricks for dealing with multiarch machines

Why do we need some new RPM tricks for dealing with multiarch machines?
Simple:

>  ; rpm -q glibc
>  glibc-2.5-10.fc6
>  glibc-2.5-10.fc6

That's not an error, that's just my machine having both the 32-bit and
the 64-bit glibc RPMs installed. On a multiarch machine it's routine
to have RPMs with identical names, and _rpm_ itself hasn't been fully
adapted for this situation.

The big RPM trick for dealing with a multiarch machine is to know that
you can pick out a specific architecture's RPM by putting the name of
the architecture on the end of the name of the RPM:

>  ; rpm -q glibc.x86_64
>  glibc-2.5-10.fc6

(You can use this format with _yum_ as well as with _rpm_.)

The other trick is using RPM query formats to actually show you which
architecture a specific RPM is for. Query formats are sufficiently
complicated that a full explanation is well beyond the scope of this
entry, but the basics are reasonably simple:

>  ; rpm --qf '%{NAME}.%{ARCH}\n' -q glibc
>  glibc.x86_64
>  glibc.i686

The normal '_rpm -q_' output format is
'%{NAME}-%{VERSION}-%{RELEASE}\n', or '%{N}-%{V}-%{R}\n' in the compact
form (technically this is slightly incorrect because it omits the
epoch, but that almost never matters). To add the architecture you use
an explicit query format of '%{N}-%{V}-%{R}.%{ARCH}\n', and for many
purposes just the name and the architecture is enough, so you can just
use '%{NAME}.%{ARCH}\n'.

(And the '\n' is important. Many a time I've accidentally left it out
and gotten all of the output smashed together into one line.)

There is probably something you can set up in your _.rpmmacros_ file
to make _rpm_ use this query format by default, but I don't know it.
You can just make a cover script instead, so you don't have to type the
query format all the time:

 ; cat rpmq
 #!/bin/sh
 exec rpm --qf '%{N}-%{V}-%{R}.%{ARCH}\n' "$@"

(My fingers are busy telling me that this should also supply the '_-q_'
argument too, so I can just do '_rpmq kernel_' and it'll work.)