root@lithium:~# aptitude search kernel-headers
v   kernel-headers                                         -                                                                 
v   kernel-headers-2.4                                     -                                                                 
p   kernel-headers-2.4.27-2                                - Header files related to Linux kernel version 2.4.27             
p   kernel-headers-2.4.27-2-386                            - Linux 2.4.27 kernel headers for 386                             
p   kernel-headers-2.4.27-2-586tsc                         - Linux 2.4.27 kernel headers for Pentium-Classic                 
p   kernel-headers-2.4.27-2-686                            - Linux 2.4.27 kernel headers for PPro/Celeron/PII/PIII/P4        
p   kernel-headers-2.4.27-2-686-smp                        - Linux 2.4.27 kernel headers for PPro/Celeron/PII/PIII/P4 SMP    
p   kernel-headers-2.4.27-2-k6                             - Linux 2.4.27 kernel headers for AMD K6/K6-II/K6-III             
p   kernel-headers-2.4.27-2-k7                             - Linux 2.4.27 kernel headers for AMD K7                          
p   kernel-headers-2.4.27-2-k7-smp                         - Linux 2.4.27 kernel headers for AMD K7 SMP                      
v   linux-kernel-headers                                   -                                                                 
p   pistachio-kernel-headers                               - L4 microkernel implementation - kernel headers                  
root@lithium:~# uname-a
-bash: uname-a: command not found
root@lithium:~# uname -a
Linux lithium 2.6.17-11-generic #2 SMP Thu Feb 1 19:52:28 UTC 2007 i686 GNU/Linux