ip to binary

tobinary() {
    ip=$1
    ip1=$(echo "$ip" | cut -f1 -d.)
    ip2=$(echo "$ip" | cut -f2 -d.)
    ip3=$(echo "$ip" | cut -f3 -d.)
    ip4=$(echo "$ip" | cut -f4 -d.)

    b1=$(echo "obase=2; $ip1" | bc)
    b2=$(echo "obase=2; $ip2" | bc)
    b3=$(echo "obase=2; $ip3" | bc)
    b4=$(echo "obase=2; $ip4" | bc)

    printf "%0.8d.%0.8d.%0.8d.%0.8d\n" $b1 $b2 $b3 $b4
}

$ tobinary 34.76.28.55
00100010.01001100.00011100.00110111
$ tobinary 34.76.51.131
00100010.01001100.00110011.10000011
$ tobinary 255.255.192.0
11111111.11111111.11000000.00000000