On BSD, unlike Linux, many utilities including dd(1) will dump a progress report when receiving SIGINFO. This was traditionally bound to ^T in shells, either by default or using stty(1).
`killall -USR1 dd` works like a charm, or for the impatient: watch killall -USR1 dd
Why they didn't give a progress bar in the first place beats me.
I regularly use progress with dd, tar and other utilities.
At least one BSD dd now has a "msgfmt" option that outputs parseable, printf-style format strings.
Truthfully, I prefer it when these basic utilities are static except for fixing bugs. Using the new features in scripts means the scripts might lose some portability.
DESCRIPTION
pv shows the progress of data through a pipeline by giving infor-
mation such as time elapsed, percentage completed (with progress
bar), current throughput rate, total data transferred, and ETA.
To use it, insert it in a pipeline between two processes, with the
appropriate options. Its standard input will be passed through to
its standard output and progress will be shown on standard error.