Simple bash script to create a Bootable ISO from macOS Sierra Install Image from Mac App Store

create_iso.sh

#!/usr/bin/env bash

# SOURCE:
# https://gist.github.com/julianxhokaxhiu/6ed6853f3223d0dd5fdffc4799b3a877

# TODO: error handling

# activate verbose standard output (stdout)
set -v
# activate debugging (execution shown)
set -x

# Current user
logged_in_user=$(logname) # posix alternative to /dev/console

# Working directory
# script_dir=$(cd "$(dirname "$0")" && pwd)

# Set $IFS to eliminate whitespace in pathnames
IFS="$(printf '\n\t')"

# create mountpoint and volume
hdiutil attach '/Applications/Install macOS Sierra.app/Contents/SharedSupport/InstallESD.dmg' -noverify -nobrowse -mountpoint '/Volumes/install_app'
hdiutil create -o '/tmp/Sierra.cdr' -size 7316m -layout SPUD -fs HFS+J
hdiutil attach '/tmp/Sierra.cdr.dmg' -noverify -nobrowse -mountpoint '/Volumes/install_build'

# copy dmg contents to volume
asr restore -source /Volumes/install_app/BaseSystem.dmg -target '/Volumes/install_build' -noprompt -noverify -erase

# remove intermediate files
rm '/Volumes/OS X Base System/System/Installation/Packages'

# copy remaining install files to volume
cp -rp '/Volumes/install_app/Packages' '/Volumes/OS X Base System/System/Installation'
cp -rp '/Volumes/install_app/BaseSystem.chunklist' '/Volumes/OS X Base System/BaseSystem.chunklist'
cp -rp '/Volumes/install_app/BaseSystem.dmg' '/Volumes/OS X Base System/BaseSystem.dmg'

# unmount volumes
hdiutil detach '/Volumes/install_app'
hdiutil detach '/Volumes/OS X Base System'

# wait for operations to finish
sleep 10

# convert dmg to iso (cdr)
hdiutil convert '/tmp/Sierra.cdr.dmg' -format UDTO -o '/tmp/Sierra.iso'

# relocate iso to desktop
mv '/tmp/Sierra.iso.cdr' "/Users/$logged_in_user/Desktop/Sierra.iso"

# cleanup
rm '/tmp/Sierra.cdr.dmg'

# deactivate verbose and debugging stdout
set +v
set +x

unset IFS

exit 0