How can I get a list of 32-bit packages that are not built in 64-bit Ubuntu ?

This bash script can be helpful:
-----------------
#!/bin/bash
for i in i386 amd64
do
  rm -rf Packages_$i packages_$i
  for j in main restricted universe multiverse
  do
    wget -O - http://archive.ubuntu.com/ubuntu/dists/lucid/$j/binary-$i/Packages.bz2 | bzcat |grep 'Package'| awk '{print $2}' >> packages_$i
  done
  sort packages_$i | uniq > Packages_$i
done
echo "Packages in i386 that are not in amd64:"
diff Packages_i386 Packages_amd64 |grep '<' | sort | awk '{print $2}'
------------

After running the script I got the followin output:

Packages in i386 that are not in amd64:
ardour-i686
athcool
atitvout
avifile-win32-plugin
bsign
circlepack
cobalt-panel-utils
dietlibc
digitools
dvisvga
fdflush
fenix
flashplugin-nonfree-extrasound
fp-units-i386
fso-usaged
gatos
gdb64
ggcov
gkrellm-x86info
glide2-bin
gmod
gnome-speech-dectalk
gogo
gstreamer0.10-pitfdll
ikarus
imaze-lesstif
imazesrv
imaze-xaw
imaze-xlabed
imaze-xview
inn2-lfs
kon2
lib64asound2
lib64asound2-dev
lib64asound2-plugins
lib64bz2-1.0
lib64bz2-dev
lib64expat1
lib64expat1-dev
lib64ffi5
lib64ffi-dev
lib64gcc1
lib64gcc1-dbg
lib64gfortran3
lib64gfortran3-dbg
lib64gomp1
lib64gomp1-dbg
lib64mudflap0
lib64mudflap0-dbg
lib64ncurses5
lib64ncurses5-dev
lib64objc2
lib64objc2-dbg
lib64readline5
lib64readline5-dev
lib64readline6
lib64readline6-dev
lib64stdc++6
lib64stdc++6-4.1-dbg
lib64stdc++6-4.3-dbg
lib64stdc++6-4.4-dbg
lib64z1
lib64z1-dev
liballegro4.2-plugin-svgalib
libatlas-3dnow-dev
libatlas3gf-3dnow
libatlas3gf-sse
libatlas3gf-sse2
libatlas-sse2-dev
libatlas-sse-dev
libc6-amd64
libc6-dev-amd64
libc6-i686
libc6-xen
libcomplearn-mod-ppmd
libcomplearn-mod-ppmdx
libfreebasic
libgatos0
libgatos-dev
libgl1-mesa-swx11-i686
libglide2
libglide2-dev
libmysqlcppconn-stlport4
libmysqlcppconn-stlport-dev
libopenspc0
libopenspc-dev
librtai1
librtai-dev
librte1
librte-dev
libsdl-stretch-0-3
libsdl-stretch-dev
libstlport4.6-dev
libstlport4.6ldbl
libvideo-info-perl
libxflaim3.2
libxflaim-dev
lightning
linux-386
linux-backports-modules-alsa-2.6.32-21-generic-pae
linux-backports-modules-alsa-lucid-generic-pae
linux-backports-modules-headers-lucid-generic-pae
linux-backports-modules-wireless-2.6.32-21-generic-pae
linux-backports-modules-wireless-lucid-generic-pae
linux-generic-pae
linux-headers-2.6.32-21-386
linux-headers-2.6.32-21-generic-pae
linux-headers-386
linux-headers-generic-pae
linux-headers-lbm-2.6.32-21-generic-pae
linux-image-2.6.32-21-386
linux-image-2.6.32-21-generic-pae
linux-image-386
linux-image-generic-pae
longrun
lphdisk
martian-modem
martian-modem-source
mit-scheme
mit-scheme-dbg
mknbi
mozart
mpg123-oss-3dnow
mpg123-oss-i486
mwavem
nestra
partimage
partimage-server
paxtest
pforth
ppmd
pptview
pstack
python-psyco
radiance-sse3
retty
rio
rtai
rtai-source
s3switch
sabre
sb16ctrl-bochs
scsh-0.6
set6x86
sl-modem-source
spicctrl
strace64
tcc
tendra
userful-multiplier
workman
xgmod
xjove
xmame-svga
xserver-xorg-video-amd
xserver-xorg-video-amd-dbg
xserver-xorg-video-geode
xserver-xorg-video-geode-dbg
xserver-xorg-video-glide
xvmount
zsnes