JSON output for -tr ( calculate traffic ) about vnstat

[vergoh]

The JSON output is currently only an alternative format for the database dump (--exportdb) with the other alternative being the XML option (--xml). That's why it's also practically instant since it only parses the database and no other sources.

Technically, when the daemon is running, it has similar information already available than what the -tr option provides (but with a delay). The daemon knows the traffic average for the configured UpdateInterval which is likely to be suitable for most use cases. What's missing is some kind of interprocess communication for the vnstat --json command to get the traffic information from the daemon. That's something that could be worth investigating.

In what kind of scenario would JSON output for vnstat -l be usable or needed? The live mode always has a few second delay before it starts producing output and requires the user to exit the process for the output to end.

[edirpedro]

Could the JSON output came with Estimated and Average Rates too? Instead of I create another function to calculate this.