Measure pipe throughput in the shell

Question

There is a shell command that allows to measure how fast the data goes through it, so you can measure the speed of output of commands in a pipe. So instead of:

$ somecommand | anothercommand

you can do something like:

$ somecomand | ??? | anothercommand

And throughput stats (bytes/sec) are prited to stderr, I think. But I can't for the life of me remember what that command was.

Hints?

Answer 1

cpipe is probably better for these purposes, but another related program is pv (Pipe Viewer):

If you give it the --rate flag it will show the transfer rate

Answer 2

You need a utility called cpipe.

Usage:

tar cCf / - usr | cpipe -vr -vw -vt > /dev/null

Output:

...
  in:  19.541ms at    6.4MB/s (   4.7MB/s avg)    2.0MB
 out:   0.004ms at   30.5GB/s (  27.1GB/s avg)    2.0MB
thru:  19.865ms at    6.3MB/s (   4.6MB/s avg)    2.0MB
...