I want to make a pretty much redstone-less contraption, so I want to detect a command block's NBT data, so that when it gives out a comparator signal, another command block detects that and then does something. Any help?
What you want is the
stats command, with the
The command syntax for what you want to do is
stats block <x> <y> <z> set <stat> <selector> <objective>
<x> <y> <z> are the coordinates of the block running the command you want to get the result data for.
<stat> is one of
SuccessCount, depending on what you want to do (check the wiki for more information).
SuccessCount is typically the same as output redstone power, but isn't capped to 15 (IIRC, it does vary for some commands).
<objective> specify a target entity and a scoreboard objective in which to store the result. I suggest using either
@a (useful for executing directly on the players if a condition is met) or a named armor stand as the selector.
We have a command block running a
testfor command (at coordinates 1 2 3), and we want to run another command if at least 4 entities (e.g. players) qualify*. We create a (dummy) scoreboard objective called "SCObjective" and summon in an (invisible, marker) armor stand called "SCDummy". We create another command block, running
stats block 1 2 3 set SuccessCount @e[type=ArmorStand,name=SCDummy] SCObjective
Afterwards, we can use
execute @e[type=ArmorStand,name=SCDummy,score_SCObjective_min=4] ~ ~ ~ <other command>
to run our command based on the result of the testfor.
* This is one of the few cases where
testfor is useful and can not easily be replaced by
There is an alternate version of the command for use with entities:
stats entity <selector2> set <stat> <selector> <objective>
This will return a
<stat> for a command run by
<selector2> (including when running
execute off that entity).