Automatically generates macOS High Sierra (and higher?) DVD images

macOSDiscCreator.sh

#!/bin/bash
if [ $# -lt 1 ]; then
	echo "Usage: macOSDiscCreator <path to Install macOS.app>";
	exit 1;
fi;
echo "Your password is needed to create the macOS Installer image.";
sudo -v;
echo "Creating temporary macOS Installer image...";
hdiutil create -layout GPTSPUD -fs HFS+ -volname Install\ macOS -attach -type UDIF -size 8g /tmp/InstallmacOS.dmg;
sudo "$1/Contents/Resources/createinstallmedia" --nointeraction --volume /Volumes/Install\ macOS/;
volname="$(osascript -l JavaScript -e "(new RegExp('\^\[\^.\]+')).exec((new RegExp('(?:(?!\\/).)+\$')).exec('$1'))")";
echo "Copying InstallESD.dmg...";
mv "/Volumes/$volname/$volname.app/Contents/SharedSupport/InstallESD.dmg" ./;
fs=$(wc -c <InstallESD.dmg);
if [ $fs -gt 4600372992 ]; then
	if [ $fs -gt 4700372992 ]; then
		if [ $fs -gt 4707319808 ]; then
			if [ $fs -gt 8443666176 ]; then
			    if [ $fs -gt 8543666176 ]; then
				    if [ $fs -gt 8547991552 ]; then
					    hdiutil detach /Volumes/$volname/;
					    rm /Volumes/InstallmacOS.dmg;
					    rm InstallESD.dmg;
					    echo "Error: The InstallESD will not fit onto any type of disc.";
					    exit 2;
				    fi;
				    echo "Warning: The InstallESD disc will require a dual-layer DVD+R to be able to burn.";
			    else
				    echo "Warning: The InstallESD disc will require a dual-layer DVD to be able to burn.";
			    fi;
			else
				echo "Warning: The InstallESD disc will require a dual layer DVD, and a DVD-R DL may not work.";
			fi;
		else
			echo "Warning: The InstallESD disc will not burn on a single layer DVD+R.";
		fi;
	else
		echo "Warning: The InstallESD disc may have trouble burning to a single layer DVD+R.";
	fi;
fi;
echo "Creating InstallESD symlink on BaseSystem...";
mkdir /Volumes/InstallESD;
touch /Volumes/InstallESD/InstallESD.dmg;
ln -s /Volumes/InstallESD/InstallESD.dmg "/Volumes/$volname/$volname.app/Contents/SharedSupport/InstallESD.dmg";
rm -r /Volumes/InstallESD;
echo "Resizing BaseSystem...";
sudo hdiutil create -srcfolder "/Volumes/$volname/" -fs HFS+ -format UDRO -volname "$volname" -layout ISOCD "$volname.dmg";
echo "Cleaning up...";
hdiutil detach "/Volumes/$volname/";
rm /tmp/InstallmacOS.dmg;
echo "Created InstallESD.dmg and $volname.dmg in the current directory. Please burn InstallESD.dmg as a file (so the disc has the InstallESD.dmg file inside) and $volname.dmg as an image (so the disc has the contents of $volname.dmg inside).";