Subject: Re: [PATCH iproute2-next 15/15] dcb: Add a subtool for the DCB ETS object

From: Stephen Hemminger <[email-masked]>
Date: Wed, 21 Oct 2020 17:11:01 -0700

On Thu, 22 Oct 2020 01:48:58 +0200
Petr Machata <[email-masked]> wrote:

> Stephen Hemminger <[email-masked]> writes:
> 
> > On Tue, 20 Oct 2020 22:43:37 +0200
> > Petr Machata <[email-masked]> wrote:
> >  
> >> Jakub Kicinski <[email-masked]> writes:
> >>  
> >> > On Tue, 20 Oct 2020 02:58:23 +0200 Petr Machata wrote:  
> >> >> +static void dcb_ets_print_cbs(FILE *fp, const struct ieee_ets *ets)
> >> >> +{
> >> >> +	print_string(PRINT_ANY, "cbs", "cbs %s ", ets->cbs ? "on" : "off");
> >> >> +}  
> >> >
> >> > I'd personally lean in the direction ethtool is taking and try to limit
> >> > string values in json output as much as possible. This would be a good
> >> > fit for bool.  
> >>
> >> Yep, makes sense. The value is not user-toggleable, so the on / off
> >> there is just arbitrary.
> >>
> >> I'll consider it for "willing" as well. That one is user-toggleable, and
> >> the "on" / "off" makes sense for consistency with the command line. But
> >> that doesn't mean it can't be a boolean in JSON.  
> >
> > There are three ways of representing a boolean. You chose the worst.
> > Option 1: is to use a json null value to indicate presence.
> >       this works well for a flag.
> > Option 2: is to use json bool.
> > 	this looks awkward in non-json output
> > Option 3: is to use a string
> >      	but this makes the string output something harder to consume
> > 	in json.  
> 
> What seems to be used commonly for these on/off toggles is the following
> pattern:
> 
> 	print_string(PRINT_FP, NULL, "willing %s ", ets->willing ? "on" : "off");
> 	print_bool(PRINT_JSON, "willing", NULL, true);
> 
> That way the JSON output is easy to query and the FP output is obvious
> and compatible with the command line. Does that work for you?

Yes, that is hybrid, maybe it should be a helper function?