A bash script using xdotool to pregenerate a Minecraft Bedrock world using Linux.

generate-world.bash

# I use this script to generate a Minecraft world.
# I run a BDS instance with sim distance 12 and a
# instance of the unofficial Linux client.
# Using a server-client setup seems to be more stable
# than running client only.
#
# Make sure your player is in creative and flying before
# you begin.

# Script parameters
sim=12 # sim distance
player=RufusAtticus # player's name
grid=10 # how big of an area do you want to search
sleep_sec=4

# Search variables
step=$(((2*sim+1)*16))
low=$((-step*grid))
high=$((step*grid))

# Find windows and pid of your minecraft instance
WID=$(xdotool search --name "Minecraft" | tail -n 1)
PID=$(xdotool getwindowpid $WID)

# function for teletporting player
function tp {
	str="tp $player $1 140 $2
"
    echo $str
    xdotool key --clearmodifiers --delay 500 --window $WID Linefeed slash \
            type --delay 100 --window $WID --clearmodifiers "$str"
    sleep $sleep_sec
}

# Focus the window and exit out of the "pause" screne
xdotool windowactivate --sync $WID
xdotool key --window $WID Escape
sleep $sleep_sec

# teleport around the first grid
for x in $(seq $low $step $high); do
	for z in $(seq $low $step $high); do
		ps -p $PID > /dev/null || exit 1
		tp $x $z
	done
done

# teleport around the second grid
low=$((low-sim*16))
high=$((high+(sim+1)*16))
for x in $(seq $low $step $high); do
	for z in $(seq $low $step $high); do
		ps -p $PID > /dev/null || exit 1
		tp $x $z
	done
done