LSL Wiki : llSetLinkPrimitiveParams

llSetLinkPrimitiveParams(integer linknumber, list rules)

The ruleset is the same as used in llSetPrimitiveParams.

A simple script to light up a prim in a linkset when touched, and unlight the last one touced using llSetLinkPrimitiveParams. Assuming this script is in each prim in the linkset.

default
{
    touch_start(integer total_number)
    {
        llSetPrimitiveParams([PRIM_FULLBRIGHT, ALL_SIDES, TRUE]);
        llSetLinkPrimitiveParams(LINK_ALL_OTHERS, [PRIM_FULLBRIGHT, ALL_SIDES, FALSE]);
     }
}

as an added bonus, besides doing stuff to other prims, you can also move an avatar sitting on the object just as if it was just another child prim, the link number for a single avatar sitting on the object will always be the primcount of the object, and after several tests I (TigroSpottystripesKatsu) calculated an approximate average between the offsets of different av heights between where an avatar is positioned when sitting on a prim with sit target defined to a given offset and positioning the avatar with this command after it is sitting to about 0.365 in the Z axis.

Notes

This function delays the script for 0.2 seconds.

Also see:
llSetLinkAlpha
llSetLinkColor
llSetLinkTexture

Functions | Link | Object | Primitive