A couple of questions

Hi,
my first question is related to llListen, in all threads about llListen that i read, guys say not to forget to remove the listen, i was wondering why is it so important and what happens if u dont remove it.

Second question is also about communication, if I have two scripts (on prims), a talking and a listening script, which communicate on, lets say channel 5, how do i make the listening script listen only to the object that belongs to it's owner, an filter all other objects?

thanx

1) Listens poll sims repeatedly on their designated channel. Leaving a listener on is slightly less laggy than leaving an llSensorRepeat on - it remains active, and checks the sim every so often for the designated chat command(s).

Anyway, you can leave listens "on" if you'd like. A few of them have very little impact on a sim. However, in bulk (100+) and being called frequently, listens can potentially lag sims to death.

Interestingly, it appears that 100 scripts with 1 listener apiece are significantly more laggy than one script with 100.


2) There are several ways to check the "owner" of an object. Since a listener happily supplies the key of the object talking to it, the simplest way is to use a sensor and a detected function.

llDetectedOwner works nicely here.

It seems to me that using llGetOwnerKey inside the listen event would be easier.

listen(integer channel, string name, key uuid, string message) {
    if (llGetOwnerKey(uuid) == llGetOwner()) {
      // do something here
    }
}

Ah yes, thanks. I sometimes forget some of these "bridge" commands exist.

Sorry, this might be a nub question, but what does the (uuid) after the llGetOwnerKey supposed to do/means?

(Ushuaia's example...)

 listen(integer channel, string name, key uuid, string message) {
        if (llGetOwnerKey(uuid) == llGetOwner()) {
          // do something here
        }
 } 

In brackets following the listen() event, we see a series of variables being declared: an integer named "channel", a string named "name", a key named "uuid" and a string named "message". These four variables are required by the listen event, though you don't have to name them the same way. All that's important is the order and that they be the same types.

So in this context the variable "uuid" will be the key of the speaker that the listen() event has been triggered by. So when the listen() event is triggered, it will determine the key of the owner of the object defined by "uuid" is, and then see if it's the same as the owner of the object that contains this script.

Edit: clarifying.

You can also make reference to this.

Do you mean per object? Or do you mean 100 as in any large number?
A script can only have up to 64 listeners, the 65th will crash the script with a "Too Many Listens" runtime error.
Also, listens do not poll sims. The sims poll the listeners
IIRC, every chat message is run through a big queue of listeners, filtered by distance, then by the filtering methods specified in llListen.

Thanx a lot everybody , that was very very helpful