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.
BSD