fix NAS sparsebundle errors script

#!/bin/sh

# http://www.garth.org/archives/2011,08,27,169,fix-time-machine-sparsebundle-nas-based-backup-errors.html

BUNDLE=???

set -e

date
echo 'chflags...'
chflags -R nouchg "$BUNDLE/"

date
echo 'hdutil...'
DISKS=`hdiutil attach -nomount -noverify -noautofsck "$BUNDLE/"`
echo $DISKS
HFS_DISK=`echo $DISKS | grep Apple_HFS | cut -f 1 | tr -d ' \t'`
echo "identified HFS(X) volume as $HFS_DISK"

date
echo 'fsck...'
fsck_hfs -drfy $HFS_DISK
# this was to wait for the log to finish before we ran fsck explicitly, as above
# grep -q 'was repaired successfully|could not be repaired' <(tail -f -n 0 /var/log/fsck_hfs.log)

date
echo 'fixing plist...'
cat "$BUNDLE/com.apple.TimeMachine.MachineID.plist" |
  # change VerificationState to zero
  awk 'BEGIN { RS = "" } { gsub(/VerificationState<\/key>[ \t\n]*<integer>2/, "VerificationState</key>\n\t<integer>0"); print }' |
  # remove RecoveryBackupDeclinedDate and write to a temp file
  awk 'BEGIN { RS = "" } { gsub(/[ \t\n]*<key>RecoveryBackupDeclinedDate<\/key>[ \t\n]*<date>[^<]+<\/date>/, ""); print }' > /tmp/fixed-plist.plist

# replace the original (don't use mv; it throws weird errors when moving across this disks)
cp /tmp/fixed-plist.plist "$BUNDLE/com.apple.TimeMachine.MachineID.plist"
rm /tmp/fixed-plist.plist

date
echo 'done!'
echo 'eject the disk from your desktop if necessary, then rerun Time Machine'

# this command will tell you who's using the disk, if ejecting is a problem:
# sudo lsof -xf +d /Volumes/disk<?> # or possibly just $BUNDLE