Minecraft – Command block questions using the execute command

minecraft-commandsminecraft-java-edition

What I want to do is use the execute command to randomly pick a custom named mob or entity. I already have this command:

execute @r[type=Boat] ~ ~ ~ setblock ~ ~-2 ~ redstone_block

which I am using to place a redstone block and select one of five categories, but then if I want to use the same command on a sheep, for example, I want it to select from the ones I summon and not randomly find one in the wild (which I figure that's what it's doing, because it was saying that the command was executed properly). The problem is that I have no idea how to go about making that work. I've tried a couple of things, but it either came back with an error or executed it on a random mob in the wild.

Best Answer

You could summon the sheep with something like a custom name or scoreboard tag, then specify that name/tag in your selector:

summon Sheep ~ ~ ~ {Tags:["Summoned"]}

Then:

execute @r[type=Sheep,tag=Summoned] ~ ~ ~ setblock ~ ~-2 ~ redstone_block

Related Solutions

Minecraft – How to execute a command relative to an entity

The /execute command is used to execute another command relative to something, the syntax you'll need is:

/execute <entity> <x> <y> <z> <command>

You should use target selectors with selector arguments to select to entity you want to execute from.

To summon TNT from an item drop, you could do:

/execute @e[type=Item] ~ ~ ~ /summon PrimedTnt

(Be careful with this command, as all item drops will act as a grenade)

Minecraft – How to mark a entity after it executes a command successfully

You will want to use CommandStats, which are a set of triggers stored on an entity that will modify a target's score based on the success of commands run by the entity.

For example, you will want to use the "SuccessCount" trigger, which stores the number of successful iterations of a command (and in the case of /testforblocks, will either be 0 for failure or 1 for success). You could also use "AffectedBlocks", which returns the number of matched blocks (0 for failure or the number of blocks found via /testforblocks).

Prerequisites

Objective to hold the return value from CommandStats triggers:

/scoreboard objectives add Results dummy

You have a couple options for applying the triggers to the entities. The most direct way would be to use the CommandStats compound directly when summoning:

/summon ArmorStand ~ ~1 ~ {CustomName:"craft",CommandStats:{SuccessCountName:"@e[type=ArmorStand,c=1]",SuccessCountObjective:"Results"}}

Or you could use the /stats command. The second selector is not translated in this command, and is stored as literally written in the CommandStats compound like above:

/stats entity @e[type=ArmorStand,name=craft] set SuccessCount @e[type=ArmorStand,c=1] Results

In order for these triggers to modify a target's score, that target must be tracked in the objective prior.

/scoreboard players set @e[type=ArmorStand,name=craft] Results 0

Detection

Your initial command.

/execute @e[type=ArmorStand,name=craft] ~ ~ ~ /testforblocks -15 56 -225 -15 56 -225 ~ ~ ~

Now the armor stand will have a "Results" score of 1 if it succeeded or 0 if it failed. You can then target the relevant armor stands.

/execute @e[type=ArmorStand,name=craft,score_Results_min=1] ~ ~ ~ /blockdata ~ ~ ~ {Items:[0:{Slot:4b,id:"minecraft:spawn_egg",Count:1b,tag:{RepairCost:0,display:{Name:"Sponge"},EntityTag:{id:"Blaze"}},Damage:0s}]}

There is no need to reset their score to 0 because it will do so the next time /testforblocks fails.