ubuntu@ubuntu:~$ sudo apt-get install testdisk
E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable)
E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?
ubuntu@ubuntu:~$ sudo apt-get install testdisk
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package testdisk
ubuntu@ubuntu:~$ sudo apt-get update
Ign cdrom://Ubuntu 11.04 _Natty Narwhal_ - Release i386 (20110427.1) natty InRelease
Ign cdrom://Ubuntu 11.04 _Natty Narwhal_ - Release i386 (20110427.1) natty/main TranslationIndex
Ign cdrom://Ubuntu 11.04 _Natty Narwhal_ - Release i386 (20110427.1) natty/restricted TranslationIndex
Ign cdrom://Ubuntu 11.04 _Natty Narwhal_ - Release i386 (20110427.1) natty/main Translation-en_US
Ign cdrom://Ubuntu 11.04 _Natty Narwhal_ - Release i386 (20110427.1) natty/main Translation-en
Ign cdrom://Ubuntu 11.04 _Natty Narwhal_ - Release i386 (20110427.1) natty/restricted Translation-en_US
Ign cdrom://Ubuntu 11.04 _Natty Narwhal_ - Release i386 (20110427.1) natty/restricted Translation-en
Ign http://archive.ubuntu.com natty InRelease                                  
Ign http://archive.ubuntu.com natty-updates InRelease                          
Ign http://security.ubuntu.com natty-security InRelease                      
Get:1 http://archive.ubuntu.com natty Release.gpg [198 B]
Get:2 http://security.ubuntu.com natty-security Release.gpg [198 B]
Get:3 http://archive.ubuntu.com natty-updates Release.gpg [198 B]
Get:4 http://security.ubuntu.com natty-security Release [39.8 kB]
Get:5 http://archive.ubuntu.com natty Release [39.8 kB]
Get:6 http://security.ubuntu.com natty-security/main Sources [92.3 kB]  
Get:7 http://archive.ubuntu.com natty-updates Release [39.8 kB]
Get:8 http://archive.ubuntu.com natty/main Sources [862 kB]       
Get:9 http://security.ubuntu.com natty-security/restricted Sources [14 B]    
Get:10 http://security.ubuntu.com natty-security/main i386 Packages [280 kB]   
Get:11 http://security.ubuntu.com natty-security/restricted i386 Packages [14 B]
Ign http://security.ubuntu.com natty-security/main TranslationIndex            
Ign http://security.ubuntu.com natty-security/restricted TranslationIndex
Ign http://security.ubuntu.com natty-security/main Translation-en_US           
Ign http://security.ubuntu.com natty-security/main Translation-en
Ign http://security.ubuntu.com natty-security/restricted Translation-en_US
Ign http://security.ubuntu.com natty-security/restricted Translation-en
Get:12 http://archive.ubuntu.com natty/restricted Sources [4,104 B]
Get:13 http://archive.ubuntu.com natty/main i386 Packages [1,550 kB]
Get:14 http://archive.ubuntu.com natty/restricted i386 Packages [8,986 B]
Ign http://archive.ubuntu.com natty/main TranslationIndex
Ign http://archive.ubuntu.com natty/restricted TranslationIndex
Get:15 http://archive.ubuntu.com natty-updates/main Sources [155 kB]
Get:16 http://archive.ubuntu.com natty-updates/restricted Sources [753 B]
Get:17 http://archive.ubuntu.com natty-updates/main i386 Packages [438 kB]
Get:18 http://archive.ubuntu.com natty-updates/restricted i386 Packages [839 B]
Ign http://archive.ubuntu.com natty-updates/main TranslationIndex              
Ign http://archive.ubuntu.com natty-updates/restricted TranslationIndex        
Ign http://archive.ubuntu.com natty/main Translation-en_US                     
Ign http://archive.ubuntu.com natty/main Translation-en                        
Ign http://archive.ubuntu.com natty/restricted Translation-en_US               
Ign http://archive.ubuntu.com natty/restricted Translation-en                  
Ign http://archive.ubuntu.com natty-updates/main Translation-en_US             
Ign http://archive.ubuntu.com natty-updates/main Translation-en                
Ign http://archive.ubuntu.com natty-updates/restricted Translation-en_US       
Ign http://archive.ubuntu.com natty-updates/restricted Translation-en          
Fetched 3,512 kB in 6s (531 kB/s)                                              
Reading package lists... Done
ubuntu@ubuntu:~$ sudo apt-get install testdisk
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package testdisk
ubuntu@ubuntu:~$ sudo apt-get update
Ign cdrom://Ubuntu 11.04 _Natty Narwhal_ - Release i386 (20110427.1) natty InRelease
Ign cdrom://Ubuntu 11.04 _Natty Narwhal_ - Release i386 (20110427.1) natty/main TranslationIndex
Ign cdrom://Ubuntu 11.04 _Natty Narwhal_ - Release i386 (20110427.1) natty/restricted TranslationIndex
Ign cdrom://Ubuntu 11.04 _Natty Narwhal_ - Release i386 (20110427.1) natty/main Translation-en_US
Ign cdrom://Ubuntu 11.04 _Natty Narwhal_ - Release i386 (20110427.1) natty/main Translation-en
Ign cdrom://Ubuntu 11.04 _Natty Narwhal_ - Release i386 (20110427.1) natty/restricted Translation-en_US
Ign cdrom://Ubuntu 11.04 _Natty Narwhal_ - Release i386 (20110427.1) natty/restricted Translation-en
Ign http://security.ubuntu.com natty-security InRelease                        
Hit http://security.ubuntu.com natty-security Release.gpg                      
Hit http://security.ubuntu.com natty-security Release 
Ign http://archive.ubuntu.com natty InRelease         
Ign http://archive.ubuntu.com natty-updates InRelease
Hit http://security.ubuntu.com natty-security/main Sources
Hit http://archive.ubuntu.com natty Release.gpg
Hit http://security.ubuntu.com natty-security/restricted Sources
Hit http://security.ubuntu.com natty-security/main i386 Packages
Hit http://security.ubuntu.com natty-security/restricted i386 Packages
Hit http://archive.ubuntu.com natty-updates Release.gpg
Ign http://security.ubuntu.com natty-security/main TranslationIndex
Ign http://security.ubuntu.com natty-security/restricted TranslationIndex
Hit http://archive.ubuntu.com natty Release    
Hit http://archive.ubuntu.com natty-updates Release
Hit http://archive.ubuntu.com natty/main Sources                      
Hit http://archive.ubuntu.com natty/restricted Sources
Hit http://archive.ubuntu.com natty/main i386 Packages
Hit http://archive.ubuntu.com natty/restricted i386 Packages
Ign http://archive.ubuntu.com natty/main TranslationIndex
Ign http://archive.ubuntu.com natty/restricted TranslationIndex
Hit http://archive.ubuntu.com natty-updates/main Sources
Hit http://archive.ubuntu.com natty-updates/restricted Sources
Hit http://archive.ubuntu.com natty-updates/main i386 Packages
Hit http://archive.ubuntu.com natty-updates/restricted i386 Packages
Ign http://archive.ubuntu.com natty-updates/main TranslationIndex
Ign http://archive.ubuntu.com natty-updates/restricted TranslationIndex
Ign http://security.ubuntu.com natty-security/main Translation-en_US
Ign http://security.ubuntu.com natty-security/main Translation-en
Ign http://security.ubuntu.com natty-security/restricted Translation-en_US
Ign http://security.ubuntu.com natty-security/restricted Translation-en
Ign http://archive.ubuntu.com natty/main Translation-en_US
Ign http://archive.ubuntu.com natty/main Translation-en
Ign http://archive.ubuntu.com natty/restricted Translation-en_US
Ign http://archive.ubuntu.com natty/restricted Translation-en
Ign http://archive.ubuntu.com natty-updates/main Translation-en_US
Ign http://archive.ubuntu.com natty-updates/main Translation-en
Ign http://archive.ubuntu.com natty-updates/restricted Translation-en_US
Ign http://archive.ubuntu.com natty-updates/restricted Translation-en
Reading package lists... Done
ubuntu@ubuntu:~$ sudo apt-get install testdisk
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package testdisk
ubuntu@ubuntu:~$