ejectdisks

ejectdisks

#!/bin/bash

#
# ejectdisks
# script to unmount all external drives on a Mac
# assumes your external volumes are all 'APFS Volume' or 'Apple_HFS'
# try `diskutil list external` to see your volumes
#
# Installation
# copy this file to /usr/local/bin or somewhere in your path and make it executable
# chmod +x path/to/ejectdisks
#
# relies on timeout (part of coreutils) and terminal-notifier
# brew install coreutils terminal-notifier
#
# Usage:
#
# unmount all external disks and stop time machine
# ejectdisks
#
# show what would happen without actually ejecting disks or stopping time machine
# ejectdisks --dry-run
#


dryrun=$(echo $* | grep -e "\b--dry-run\b")

if [ "$dryrun" ]
then
  echo "Dry run: no disks will be ejected. Time Machine will not be stopped. Example output shown below."
fi

# helper methods
function checkError {
  EXITCODE=$?
  if [ "$EXITCODE" -ne "0" ]; then
      exit $EXITCODE
  fi
}

function checkErrorAndNotify {
  EXITCODE=$?
  if [ "$EXITCODE" -ne "0" ]; then
      echo $1 $2
      terminal-notifier -title "$1" -message "$2"
      exit 1
  fi
}

function ejectdisks {
  echo "Checking for extenal disks..."

  # reduces diskutil output to a series of lines like 'External HD•disk5s1'
  # probably a better way to do this with sed - suggestions welcome
  disks=$(timeout -v 5 diskutil list external | grep -E '(APFS Volume|Apple_HFS)' | grep -v KB | perl -pe 's/.*(APFS Volume|Apple_HFS) (.*)   +\d+\.?\d* [GT]B +(.*)/\2•\3/g' | perl -pe 's/ +•/•/g')

  checkErrorAndNotify "Oops!" "There was a problem reading external disks."

  if [ "$disks" ]
  then
    echo "$disks" | while read line ; do
      # split the line on • to get diskname and devicename
      diskname=$(echo $line | cut -d• -f1)
      devicename=$(echo $line | cut -d• -f2)
      echo "Ejecting $diskname..."
      if ! [ "$dryrun" ]
      then
        diskutil eject /dev/$devicename
      fi
      checkError
    done
  fi
}

# execution starts here
terminal-notifier -title "Unmounting disks" -message "Please wait…"

# stop time machine
echo "Stopping Time Machine..."
if ! [ "$dryrun" ]
then
  timeout -v 30 tmutil stopbackup
fi
checkErrorAndNotify "Oops!" "There was a problem stopping time machine."

ejectdisks
checkErrorAndNotify "Oops!" "There was a problem ejecting some disks."

echo "All disks unmounted."
terminal-notifier -title "All disks unmounted" -message "Get out of here." -sound "Glass"
# open /Volumes # uncomment to open /Volumes in Finder after ejecting disks

if [ "$dryrun" ]
then
  echo "Dry run complete."
fi

Companion to mountdisks

Example output:

❯ ejectdisks
Stopping time machine...
Checking for extenal disks...
Ejecting Wrangler...
Disk /dev/disk5s2 ejected
Ejecting Tonka...
Disk /dev/disk7s1 ejected
Ejecting Spree...
Disk /dev/disk8s2 ejected
Ejecting Frog Ville...
Disk /dev/disk10s1 ejected
All disks unmounted.