watchdiff is a handy perl script to watch numeric differences in periodically running output of its command line.

Its somewhat similar to watch -d but instead of just printing the output, it printsout all numbers "differences".

Example is

~/watchdiff 1 "ifconfig enp1s0f1 | grep packets"

ifconfig enp1s0f1 | grep packets
INCONSISTENT
          RX packets:4066342529 errors:0 dropped:0 overruns:0 frame:0
          TX packets:14323464927 errors:0 dropped:0 overruns:0 carrier:0

          RX packets:<154,935> errors:0 dropped:0 overruns:0 frame:0
          TX packets:<156,114> errors:0 dropped:0 overruns:0 carrier:0

          RX packets:<154,668> errors:0 dropped:0 overruns:0 frame:0
          TX packets:<156,154> errors:0 dropped:0 overruns:0 carrier:0

This essentially shows dynamic packet per second rates on the adapter.

https://github.com/cail/

BSD

https://github.com/cail/watchdiff