Quick script to write a bootable UEFI Windows ISO to USB in macOS

write_bootable_windows_iso_to_usb.sh

#!/bin/bash

# System: Darwin x86_64 19.6.0 (macOS 10.15.6 19G2021)
# Author: Othyn (https://github.com/othyn)
# Source: https://gist.github.com/othyn/29b82e39eb8cdd98adf1be77cbb62700
# Dependencies: pv, wimlib
# Licence: MIT

DEFAULT="\x1b[0m"
RED="\x1b[31m"
GREEN="\x1b[32m"
YELLOW="\x1b[33m"

newLine () {
    printf "\n"
}
printLine () {
    printf ">>> ${1}\n"
}
defaultLine () {
    printLine "${DEFAULT}${1}"
}
redLine () {
    printLine "${RED}${1}${DEFAULT}"
}
greenLine () {
    printLine "${GREEN}${1}${DEFAULT}"
}
yellowLine () {
    printLine "${YELLOW}${1}${DEFAULT}"
}

# Dependency checks
if ! command -v pv >/dev/null 2>&1 ; then
    redLine "Please install pv first, via 'brew install pv' is easiest, then try again."
    exit 1
fi
if ! command -v wimlib-imagex >/dev/null 2>&1 ; then
    redLine "Please install wimlib first, via 'brew install wimlib' is easiest, then try again."
    exit 1
fi

# Check the path to the image to flash was provided
if [[ -z "${1}" ]] ; then
    redLine "Please provide the path to the image to flash and try again!"
    exit 1
fi

# Set the image path to use
imagePath="${1}"
imageDirname="$(dirname "${imagePath}")"
imageBasename="$(basename "${imagePath}")"

if [[ ! -f "${1}" ]] ; then
    redLine "Invalid filepath provided. Please try again!"
    exit 1
fi

displayDisks () {
    # Clear the console
    clear

    defaultLine "These are the disks currently available on your system:"
    newLine

    # Spit out all available disks
    diskutil list
}

# Set disk validity
validDisk=false

displayDisks

while [ "$validDisk" = false ]; do
    # Ask which disk number they wish to flash
    greenLine "Please enter the disk number of the disk you wish to flash: "

    read usbDiskNumber

    if [[ -e /dev/disk"${usbDiskNumber}" ]]; then
        validDisk=true
    else
        redLine "Disk /dev/disk${usbDiskNumber} not found!"
    fi
done

displayDisks

greenLine "Disk /dev/disk${usbDiskNumber} has been selected."
redLine "This disk will be permanently erased!"
yellowLine "Are you sure you want to continue? Y/n: "

read diskWipeConfirm

# Confirm that they want to wipe the selected disk
if [[ "$diskWipeConfirm" != Y ]]; then
    greenLine "User didn't want to write, aborting!"
    exit 0
fi

usbVolumeName="WINSTALL"

newLine
greenLine "Partitioning the entire of disk${usbDiskNumber} to MBR Fat32 with name '${usbVolumeName}'..."

# Partition the disk as required
diskutil eraseDisk MS-DOS "${usbVolumeName}" MBR /dev/disk"${usbDiskNumber}"

sleep 1

isoMountPath="${HOME}/mount/WINSTALL_SRC"

newLine
greenLine "Mounting ISO to temporary location '${isoMountPath}'..."

if [[ ! -d "${isoMountPath}" ]] ; then
    mkdir -p "${isoMountPath}"
else
    diskutil unmount "${isoMountPath}"
fi

hdiutil mount -mountPoint "${isoMountPath}" "${imagePath}"

newLine
greenLine "Copying all but install.wim from '${isoMountPath}/' to '/Volumes/${usbVolumeName}'..."

rsync -vha --progress --exclude=sources/install.wim "${isoMountPath}/" "/Volumes/${usbVolumeName}"

newLine
greenLine "Creating install.wim chunks an placing into '/Volumes/${usbVolumeName}/sources'..."
yellowLine "This may take some time and appear to not do anything, bare with it..."

mkdir -p "/Volumes/${usbVolumeName}/sources"

wimlib-imagex split "${isoMountPath}/sources/install.wim" "/Volumes/${usbVolumeName}/sources/install.swm" 4000

newLine
greenLine "Cleaning up temporary mounts and directories..."

diskutil eject "${isoMountPath}"
rm -r "${isoMountPath}"

newLine
greenLine "Flash complete!"
exit 0