Quoth Roland Mainz on Wed, Jun 04, 2008 at 11:23:33PM +0200: > David Bustos wrote: > > Quoth Nicolas Williams on Wed, Jun 04, 2008 at 12:52:43PM -0500: > > > My simple proposal would be used as I described: > [snip] > > Those output modes seem designed for dumping all of the property groups > > of a service or instance. Somehow, I don't think that would be common. > > What would you need (or beter: What do you think would be a common > usage) ?
I think the most common usage is to retrieve a single value from a particular property, and if the property is of the wrong type or doesn't have a single value (no values or more than one), consider it an error. This is covered by 6419671 "svcprop -1 & -T". Next would be to iterate over all the values of a particular property. This was the original goal of svcprop's output format, which is why it quotes all shell metacharacters within each value and separates the values by spaces. Apparently, though, this doesn't work. I think most developers would also want svcprop to fail if the property was of a type different than expected, which could be done with the -T in the RFE above. Then there are developers who create property groups to represent separate objects. They would want to iterate over all property groups in the running snapshot of a service instance, probably filtered by property group type. Then they'd want to access particular properties of each property group. Though if they want this to be robust against modification, then they'd have to use libscf anyway, so it's not clear to me we should facilitate this in svcprop. And finally there might be developers who create variable numbers of properties in a particular property group, and they might want to iterate over them. This could be done with current svcprop output, though perhaps not as efficiently as possible. David
