Organizes Items in my ~/Downloads Directory into their proper locations. Also works in pretty much any shell, I wrote a separate script to test it against all the shells I had installed at the time, in debug mode. I probably should have uploaded that as well.

organize_files.sh

#!/bin/bash

usage () {
  echo >&2 "Usage: $0 [-f orce] [-v erbose] [-i nteractive]"
  exit 1
}

confirm () {
  # Maybe add Default Y or N, and perhaps switch to using select...
  read -r -p "${1:-Are you sure? [y/N]} " response
  case $response in
    [yY][eE][sS]|[yY])  true;;
    *)  false;;
  esac
}

organize_files () {
  if [ $vflag = "on" ]; then
    echo "Starting..."
  fi

  sort_documents &
  sort_pictures &
  sort_videos &
  sort_music &

  if [ $vflag = "on" ]; then
    echo "Finished..."
  fi
}

sort_documents () {
  local dest="${HOME}/Documents"
  
  for type in txt pdf doc docx odt rtf ods xls
  do
    sort_by_types "$type" "${HOME}/Downloads" "$dest"
  done
}

sort_music () {
  local dest="${HOME}/Music"

  for type in mp3 wav wma mp2 spx aac m4a
  do
    sort_by_types "$type" "${HOME}/Downloads" "$dest"
  done
}

sort_pictures () {
  local dest="${HOME}/Pictures"

  for type in png jpg gif raw bmp webp psd xcf ico svg
  do
    sort_by_types "$type" "${HOME}/Downloads" "$dest"
  done
}

sort_videos () {
  local dest="${HOME}/Videos"

  for type in mov avi webm mkv m4v
  do
    sort_by_types "$type" "${HOME}/Downloads" "$dest"
  done
}

sort_by_types () {
  types=$1
  target=$2
  dest=$3

  type_regex="\\("${types[1]}
  #type_expansion="("${types[1]}

  for t in "${types[@]:1:${#types[*]}}"; do
    type_regex="${type_regex}\\|${t}"
    # type_expansion="${type_expansion}|${t}"
    # mv ${target}/*.$t $dest
  done

  if [ $vflag = "on" ]; then
    # I wonder if $(basename $dest) is any better
    echo "Sorting ${dest##*/} files that match ${types}"
  fi

  type_regex="${type_regex}\\)"
  #type_expansion="${type_expansion})"
  #mv ${target}/*.${type_expansion} ${dest}

  if [ $vflag = "on" ]; then
    find ${target} -type f -regex ".*\.${type_regex}" | parallel -X mv -v {} ${dest}
  elif [ $fflag = "on" ]; then
    find ${target} -type f -regex ".*\.${type_regex}" | parallel -X mv -f {} ${dest}
  else
    find ${target} -type f -regex ".*\.${type_regex}" | parallel -X mv {} ${dest}
  fi
}

lockfile=/tmp/organize_downloads.lock
if mkdir "$lockfile"
then
  trap "rm -f "$lockfile" >/dev/null 2>&1" 0
  trap "exit 2" 1 2 3 15

  fflag=off # Forced Execution - Don't Prompt
  vflag=off # Verbosity
  while getopts fv: opt
  do
    case "$opt" in
      f)  fflag=on;;
      v)  vflag=on;;
      \?) usage;;
    esac
  done
  shift `expr $OPTIND - 1`

  if [ $fflag = "on" ]; then
    organize_files
  else
    if [ confirm ]; then
      organize_files
    else
      exit 0
    fi
  fi
else
  exit 1
fi