Watch is a small script in Inferno sh to date and print differences in an arbitrary command's output, each time the output of that command changes. (Not an original idea.)

https://github.com/catenate/inferno-cat/blob/master/sh-infer...

You could obviously update it to execute an arbitrary command: e.g. (plot watch.out.new.$pid) instead of diff, whenever a data-generating program generates a different set of data.

https://github.com/catenate/inferno-cat/blob/master/sh-infer...