I need a way to monitor the accumulated total number of bytes written to the disk by a process via the terminal. I've looked around quite a bit, and found several answers either saying to use pv, or iotop. However, pv is not installed on macOS out-of-the-box, and the version of iotop installed on macOS lacks the -a accumulated switch.
On top of that iotop requires SIP be disabled in newer versions of macOS, meaning it won't work with an out-of-the-box Mac. I need a method using tools built into macOS, they can require root access, they cannot require any non-stock macOS dependencies, e.g. Macports/Brew based software. Preferably in the stock version of Bash.
iotophas a switch for this on Linux, but the version built into Sierra doesn't mention or support that switch. I also need a way that doesn't require SIP be disabled. – Alison E.E. Sep 13 '17 at 08:03