PV (progress viewer), a computer forensics friend

On your linux command line, whether you disk image, netcat, copy a giant dd file, you often have the drawback of the no feedback = good feedback of the unix world : sometimes you simply don't know if you gonna stay in front of your blinking cursor 5 minutes or 5 hours.

It is where I find the pv tool extremely nice.

To install it under gentoo :

emerge -a sys-apps/pv

Example of a disk imaging session (all as root): 

First make sure the targeted hard drive here /dev/sdb will be accessed read-only (for those still without a physical write blocker :P ):

losetup /dev/loop0 -r /dev/sdb

pv acts by default somewhat like cat :

pv /dev/loop0 | tee image.dd | md5sum
10.8GB 0:01:24 [ 133MB/s] [==>                                                 ]  4% ETA 0:28:55
At the end of the process it gives you nicely your md5sum:
1dec4b2b97cee8f456f5b3b6c0164d56  -