Must I *specify* all llSetPrimitiveParams PRIM_TYPE parameters?

When issuing a llSetPrimitiveParams command with a PRIM_TYPE, is it essential to specify every parameter if I only need to alter one or two?
If not, what's the syntax?

Obviously I can ll*Get*PrimitiveParams first to store all of the other parameters, but I'd prefer to avoid that if it's possible.

Way?

your not gonna get too many responses this time of night, and i honestly dont know

best i can say is try it untill someone else posts

i really dont think you can only spec a cupple peramaters becuase it doesnt know which vector float or whatever else is which

You only need to specify the ones you need.

Ok, but if the one I need is a PRIM_TYPE there are quite a few variables that pop out of the resulting list.
Must I 'llGet..' this entire bunch of variables before I 'llSet...' any one of them?
Some variables seem to respond to zero as meaning 'no change', but others clearly do not.
('Hollow' on a tube vs a cylinder for example...iirc)

Yes, I think you will need to supply all elements for a given Constant Name, otherwise you will get this error:

llSetPrimitiveParams error running rule #1: unknown rule.

In these cases the parameters are each a list and each of those lists must be properly formed.

Yes because parameters are positional (cut is #2, hollow #3...) and you can't specify hollow=value.

However, that's the way to go.

list params = llGetPrimitiveParams();
params = llListReplaceList(params, [param_value], param_index, param_index);
llSetPrimitiveParams(params);

Sorry misread the orifinal post, yes, for a particular constant you ahve to supply all the parameters or else it will give you an error. I like Jeff's solution I'll have to make a note of that.

Indeed! I haven't worked my way through reading/understanding all of the functions yet, so it's great when someone shows me an obvious shortcut that i would have otherwise spent ages coding around in a convoluted manner.
llListReplaceList eeeehhh?
Eeeexcellent.