Rotation of line between two points

How can I calculate the rotation of a line connecting two known points?

llRotBetween()

http://wiki.secondlife.com/wiki/LlRotBetween

Tell me more! rotate? around one end or the middle or the global zero? Or do you want to rotate an object with the line as an axis? Mind reading isn't my best

From the other thread that you answered:

rotation slerp( rotation a, rotation b, float t ) {
return llAxisAngle2Rot( llRot2Axis(b /= a), t * llRot2Angle(b)) * a;
}//Written collectively, Taken from http://forums.secondlife.com/showthread.php?p=536622

I'm still trying to figure this out. So, if I make a 90 degree turn, I want to place a prim rotated at 45 degrees to each line. A 60 degree turn would yield a 30 degree rotation, and so forth all the way up to (but not including) 360 degrees.)

I am now using the slerp function and llRotBetween mentioned earlier but cannot get the rotations right to pass to it.

I have pared my code down to this so maybe someone can see what I am doing wrong:

rotation slerp( rotation a, rotation b, float t ) 
{
    return llAxisAngle2Rot( llRot2Axis(b /= a), t * llRot2Angle(b)) * a;
}//Written collectively, Taken from http://forums.secondlife.com/showthread.php?p=536622

rotation RotBetween(vector start, vector end) //adjusts quaternion magnitude so (start * return == end) 
{//Authors note: I have never had a use for this but it's good to know how to do it if I did.
    rotation rot = llRotBetween(start, end);
    
    llSay(0, (string)start);
    llSay(0, (string)end);
    
    if(start)
    {
        if(end)
        {
            float d = llSqrt(llVecMag(end) / llVecMag(start));
            return <rot.x * d, rot.y * d, rot.z * d, rot.s * d>;
        }
    }
    return rot;
}//Strife 

default
{
    state_entry()
    {
    }

    touch_start(integer total_number)
    {
        vector pos1 = <0.0, 2.0, 1.0>; //beginning
        vector pos2 = <0.0, 1.0, 1.0>; //middle
        vector pos3 = <0.0, 1.0, 2.0>; //end
            
        rotation rot1 = RotBetween(pos1, pos2); //first line
        rotation rot2 = RotBetween(pos2, pos3); //second line
        rotation rot3 = slerp(rot1, rot2, 0.5); //split the difference in the rotations
            
        llSay(0, "rot1 = " + (string)llRot2Euler(rot1));
        llSay(0, "rot2 = " + (string)llRot2Euler(rot2));

        vector EulerRot = llRot2Euler(rot3);
        llSay(0, "rot3 = " + (string)EulerRot); //this is the rotation I want to set my prim to
        llSay(0, "degrees = <" + (string)(EulerRot.x * RAD_TO_DEG) + ", " +  (string)(EulerRot.y * RAD_TO_DEG) + ", " + (string)(EulerRot.z * RAD_TO_DEG) + ">");
    }
}

With these numbers, I would expect the output to be 45 degrees, but I never get that.

Hello, is this mic on?