Watchline runs a command at an interval (similar to watch
; without clearing the screen)
To observe the behavior, compare the execution of date --iso-8601=ns | cut -d, -f2 | cut -d+ -f1
with and without precise mode:
```
$ watchline 'date --iso-8601=ns | cut -d, -f2 | cut -d+ -f1'
$ watchline -p 'date --iso-8601=ns | cut -d, -f2 | cut -d+ -f1' ```