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:~$