check partition boot flag

#!/bin/bash

if [ -z "$1" ]; then

    echo -n "Use " `basename $0` "<device>"
    echo
    echo "<device> - e.g. /dev/sda1"
fi

DEV=`echo "$1" | sed 's/[0-9]\+$//'`
PART=`echo "$1"|sed 's/[^0-9]//g'`

if [ -z "$DEV" ];then
    echo "Bad device!"
    exit 1
fi

if [ -z "$PART" ];then
    echo "Bad partition!"
    exit 1
else
    if [ "$PART" -eq 0 ];then
    echo "Bad partition!"
    exit 1
    fi
fi

PARTREC=$(dd if=$DEV bs=1 count=16 status=none skip=$((0x1BE + 16 * ($PART - 1) )) | od -t x1 -A n |awk '{print $1}')

if [ -z "$PARTREC" ];then
    echo "Data error"
    exit 1
fi

case "$PARTREC" in
    00)
    echo "$DEV$PART is NOT active partition ($PARTREC)"
    ;;
    80)
    echo "$DEV$PART is ACTIVE partition ($PARTREC)"
    ;;
    *)
    echo "$DEV$PART Result unknow ($PARTREC)"
    ;;
esac