ubuntu@ubuntu:~$ sudo apt-get install testdisk
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following NEW packages will be installed:
  testdisk
0 upgraded, 1 newly installed, 0 to remove and 284 not upgraded.
Need to get 324 kB of archives.
After this operation, 1,241 kB of additional disk space will be used.
Get:1 http://archive.ubuntu.com/ubuntu xenial/universe amd64 testdisk amd64 7.0-1 [324 kB]
Fetched 324 kB in 1s (259 kB/s)    
Selecting previously unselected package testdisk.
(Reading database ... 192075 files and directories currently installed.)
Preparing to unpack .../testdisk_7.0-1_amd64.deb ...
Unpacking testdisk (7.0-1) ...
Processing triggers for man-db (2.7.5-1) ...
Setting up testdisk (7.0-1) ...