http://www.ivarch.com/programs/pv.shtml ᔥ
pv – Pipe Viewer – is a terminal-based tool for monitoring the progress of data through a pipeline.
It can be inserted into any normal pipeline between two processes to give a visual indication of
how quickly data is passing through, how long it has taken, how near to completion it is, and an
estimate of how long it will be until completion.
Example from this blog post:
$ pv access.log | gzip > access.log.gz
611MB 0:00:11 [58.3MB/s] [=> ] 15% ETA 0:00:59