Bash script to prefix filenames with their containing folder

#!/bin/bash

DRYRUN=false

while getopts 'd' flag; do
  case "${flag}" in
    d) DRYRUN=true ;;
    *) error "Unexpected option ${flag}" ;;
  esac
done

for dir in *; do
    if test -d "$dir"; then
        (
            cd $dir
            for file in *; do
                if test -f "$file"; then
                    (
                        newfile=$dir.${file}
                        if [ "$DRYRUN" = true ] ; then
                            echo "$file" ../"$newfile"
                        else
                            mv "$file" ../"$newfile"
                        fi
                    )
                fi
            done
        )
    fi
done