[arakuta]

This is simple! All you have to know is basics about creating some commands!

https://sampforum.blast.hk/showthread.php?tid=280476

To attach an objecto into another object use this:

https://sampwiki.blast.hk/wiki/AttachObjectToObject

To 'open' gates, just move them using this:

https://sampwiki.blast.hk/wiki/MoveObject

To 'close' gates, just move them back to the original position.

Try, and post your doubts here

The final result should be like this:

pawn Код:

CMD:opengateandattach(playerid)
{
    //MoveObect...
    //AttachObjectToObject...
    SendClientMessage(playerid,-1,"You opened the gate!");
    // Don't forget a way to close the gate,  and a check to know if the gate is open will be also good ;)
    return 1;
}