dd.sh

#!/bin/bash

DD=/bin/dd

for i in $@; do
  if [[ "$i" =~ ^of= ]]; then
    OF=${i/of=/}
  fi
done

for i in $( mount | awk '{print $1}' ); do
  if [[ "$i" =~ ^$OF ]]; then
    echo $OF seems to specify the file system in the mount.
    echo Force Quit.
    exit -1
fi
done

`$DD $@`