Erase & Install for macOS (also works with Catalina 10.15, Monterey 11, Big Sur 12, Ventura 13, Sonoma 14)

MacOSEraseInstall.sh

#!/bin/bash

##  Erase & Install for macOS  (works with Catalina 10.15, Monterey 11,
##  Big Sur 12, Ventura 13, Sonoma 14)
#
#   Bash script for erasing the current boot partition and starting a fresh
#   install of the current macOS.

################
#   WARNING!   #
################

#   This is a lethal script and should obviously only be used by power users and
#   developers, since it wipes your boot volume!

## Copyright
#
#  Unless otherwise noted the contents of this file are Copyright :copyright:2020 by
#  Christopher Allen, and are shared under [spdx:MIT License](https://spdx.org/licenses/MIT.html)
#  open-source license.

## Support My Open Source & Digital Civil Rights Advocacy Efforts
#
#  If you like these tools, my writing, my advocacy, my point-of-view, I invite you to sponsor me.
#
#  It's a way to plug into an advocacy network that's not focused on the "big guys". I work to
#  represent smaller developers in a vendor-neutral, platform-neutral way, helping us all to
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#
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#
#  -- Christopher Allen <ChristopherA@LifeWithAlacrity.com\>
#     Github: [@ChristopherA](https://github.com/ChristopherA)
#     Twitter: [@ChristopherA](https://twitter.com/ChristopherA)

# SCRIPT DETAILS:

# This script will download the latest macOS installer, install it in a hidden
# partition, and then erase the boot partition (not just the boot volume
# but any APFS volumes sharing the same partition) and install a fresh copy
# macOS.
# 
# Note that this technique does NOT erase other partitions on the same drive
# In my case, I have a separate partition named "/Volumes/Persistent/" that
# contains my scripts for restoring my settings and installing my apps and 
# development environment.
#
# It can also be useful if you have a large internal hard drive to have a
# separate "/Volumes/Time Machine/" partition for quick restoration. What I
# do is exclude from Time Machine backup "/Applications/", my "~/Dropbox" and
# other cloud sync'ed folders, "/Volumes/Persistent/", and my development
# tools and projects, as they are seperately backed up and archived, which
# makes the data saved on the "/Volumes/Time Machine/" much smaller.
# My 4TB MacBook Pro has 1TB for boot, 1.5 TB for Time Machine, and 1.5 TB
# for my "/Volumes/Persistent/" which also has my dropbox and cloud data. 

# Inspiration for this code from:
# https://grahamrpugh.com/2018/03/26/reinstall-macos-from-system-volume.html
# & https://grahamrpugh.com/2020/06/09/startosinstall-undocumented-options.html
# & https://www.jamf.com/blog/reinstall-a-clean-macos-with-one-button/

if [ ! -f "/Applications/Install macOS Ventura.app/Contents/Resources/startosinstall" ]; then
  read -p "You don't currently have a macOS installer. Download it? [y/n]:" -n 1 -r
  echo    # (optional) move to a new line
  if [[ ! $REPLY =~ ^[Yy]$ ]]
  then
    exit 1
  fi

  printf "Downloading latest macOS installer…\n"
  # --fetch-full-installer only works on Catalina 10.14+
  sudo /usr/sbin/softwareupdate \
     --fetch-full-installer \
     --full-installer-version 13.0
     # if you want a specific version

else
  printf "Installer Ready!\n"
fi

read -p "Proceed with Erase Install? This will delete everything in the boot partition. Are you sure? [Y/n]:" -n 1 -r
echo    # (optional) move to a new line
if [[ ! $REPLY =~ ^[Y]$ ]]
then
    exit 1
fi

# /Applications/Install\ macOS\ Ventura.app/Contents/Resources/startosinstall --usage

sudo /Applications/Install\ macOS\ Ventura.app/Contents/Resources/startosinstall  \
     --eraseinstall --preservecontainer --agreetolicense --nointeraction \
     --passprompt --forcequitapps --newvolumename 'Macintosh HD'

# # or you can choose to not erase and just upgrade to latest Big Sur.
# /Applications/Install\ macOS\ Ventura.app/Contents/Resources/startosinstall --agreetolicense --forcequitapps

This may require addition of --passprompt or --stdpassin