As the title says, this tool will let you monitor pipe throughput, something which I find very valuable at times, ie. how fast was my tar or cpio to another host or filesystem, or less useful like how fast does “yes | pv >/dev/null” swallow my data.
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.
Either get it from the official site and compile it yourself, or from your OS vendors package repository. Debian/Ubuntu users can do “apt-get install pv”.