DD wrapper around dd with progress output

DD

#!/bin/bash
# 
# DD is a wrapper around dd with progress output.
# 
# version: VERY BETA :-)

_verbose()
{
	echo $1
}

_kill_dd()
{
	echo "dd ($ddpid) is still running, killing...";
	kill $ddpid
}

on_die()
{
	echo "killing dd ($ddpid)"
	ps $ddpid && _kill_dd
	ps $ddpid || exit 1
}

trap 'on_die' TERM
trap 'on_die' INT

dd $@ &
ddpid=$!
_verbose "dd has pid $ddpid"

while [ 1 ];
do
	sudo kill -USR1 $ddpid 2>/dev/null || exit 0;
	sleep 1;
done

ps $ddpid && _kill_dd