root@ubuntu:/# aptitude search linux-image
p   linux-image                     - Generic Linux kernel image.
v   linux-image-2.6                 -
p   linux-image-2.6.31-10-rt        - Linux kernel image for version 2.6.31 on I
p   linux-image-2.6.32-21-386       - Linux kernel image for version 2.6.32 on i
pi  linux-image-2.6.32-21-generic   - Linux kernel image for version 2.6.32 on x
p   linux-image-2.6.32-21-generic-p - Linux kernel image for version 2.6.32 on x
p   linux-image-2.6.32-21-virtual   - Linux kernel image for version 2.6.32 on x
p   linux-image-2.6.32-22-386       - Linux kernel image for version 2.6.32 on i
pi  linux-image-2.6.32-22-generic   - Linux kernel image for version 2.6.32 on x
p   linux-image-2.6.32-22-generic-p - Linux kernel image for version 2.6.32 on x
p   linux-image-2.6.32-22-virtual   - Linux kernel image for version 2.6.32 on x
p   linux-image-2.6.32-305-ec2      - Linux kernel image for version 2.6.32 on x
p   linux-image-2.6.32-306-ec2      - Linux kernel image for version 2.6.32 on x
p   linux-image-386                 - Generic Linux kernel image
p   linux-image-ec2                 - Linux kernel image for ec2 machines
pi  linux-image-generic             - Generic Linux kernel image
p   linux-image-generic-pae         - Generic Linux kernel image
p   linux-image-rt                  - Realtime (RT) Linux kernel image
p   linux-image-server              - Linux kernel image on Server Equipment.
p   linux-image-virtual             - Linux kernel image for virtual machines
root@ubuntu:/#


root@ubuntu:/# aptitude search '~i~nlinux-image'
root@ubuntu:/# sudo aptitude search '~i~nlinux-image'
sudo: unable to resolve host ubuntu
root@ubuntu:/#