Build desired number of BlackHole drivers

build-multiple-blackholes.sh

#!/bin/bash

# copy everything from drivers/ folder to /Library/Audio/Plug-Ins/HAL/ and run
# sudo chown -R root:wheel /Library/Audio/Plug-Ins/HAL/Pipe* 
# sudo launchctl kickstart -kp system/com.apple.audio.coreaudiod

driver_num=1

build_driver_with_options() {
    number=$(printf "%02d" ${1})
    channels=${2}
    git reset --hard HEAD
    sed -i '' "s/BlackHole%ich_UID/BlackHole_pipe_${number}_${channels}ch_UID/g" BlackHole/BlackHole.h
    sed -i '' "s/BlackHole%ich_ModelUID/BlackHole_pipe_${number}_${channels}ch_ModelUID/g" BlackHole/BlackHole.h
    sed -i '' "s/BlackHole %ich/Pipe ${number} ${channels}ch/g" BlackHole/BlackHole.h
    sed -i '' -E "s/NUMBER_OF_CHANNELS[[:space:]]+2$/NUMBER_OF_CHANNELS ${channels}/g" BlackHole/BlackHole.h
    xcodebuild CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO && mv -f build/Release/BlackHole.driver "drivers/Pipe ${number} ${channels}ch.driver"
}

mkdir drivers

# Build 8 2ch drivers 
for i in {1..8}; do
    build_driver_with_options ${driver_num} 2
    ((driver_num=driver_num+1))
done

# Build 4 8ch drivers
for i in {1..4}; do
    build_driver_with_options ${driver_num} 8
    ((driver_num=driver_num+1))
done

Because 2 drivers are never enough.