Fix munpack UTF-8 names in attachments

munpack-fix.sh

#!/bin/sh
find . -type f -iname '*X=' | while read name
do
  newname=$(echo "$name" | sed 's/[[:print:]]*\/=Xutf-8XBX//I; s/X=XXX=Xutf-8XBX//gI; s/X=$//' | base64 -d )
  dir=$(echo $name | sed 's/\/=Xutf-8XBX[A-Za-z0-9X=/+-]\+//I')
  mv --verbose "$name" "${dir}/${newname}"
done

Thanks both av-gantimurov and gilles0606 for your contributions. Simple, yet effective solutions, much appreciated even years later!