Bash script to convert decimal IP to binary

Question

I need to write a script to enter 2 IP addresses and then change them to binary. I tried this script but it works just with numbers. I can't write the IP thus: 192.168.1.1, but when I write it as 100 it's working fine.

#!/bin/bash  
echo "Ebter the first ip"
read ip1
echo "Enter the second ip"
read ip2

a=`echo "obase=2;$ip1" | bc`
b=`echo "obase=2;$ip2" | bc`
echo $a
echo $b

What is wrong in my script?

You have to split the four components of the IP address and convert them separately — Andrea Corbellini, Feb 04 '16 at 12:46
Using arrays and `read`: http://stackoverflow.com/questions/10586153/split-string-into-an-array-in-bash — Andrea Corbellini, Feb 04 '16 at 12:58
What output do you expect? `2.2.2.2` should become `10.10.10.10` or `00000010000000100000001000000010` or something else? — Andrea Corbellini, Feb 04 '16 at 13:48

jyvet · Accepted Answer · 2016-02-05T21:53:01.850

1

what you can do:

#!/bin/bash

function convip()
{
    CONV=({0..1}{0..1}{0..1}{0..1}{0..1}{0..1}{0..1}{0..1})

    ip=""
    for byte in `echo ${1} | tr "." " "`; do
        ip="${ip}.${CONV[${byte}]}"
    done
    echo ${ip:1}
}

echo "Enter the first ip"
read ip1
echo "Enter the second ip"
read ip2

a=`convip "${ip1}"`
b=`convip "${ip2}"`

echo "${a}"
echo "${b}"

Result:

Enter the first ip
1.1.1.1
Enter the second ip
2.2.2.2
00000001.00000001.00000001.00000001
00000010.00000010.00000010.00000010

EDIT: updated to keep dots

edited Feb 05 '16 at 21:53

answered Feb 04 '16 at 23:22

jyvet

2,021
15
22

thanks for ur help but how i can add dot between the binarys number – Miron Feb 05 '16 at 12:40
1

nitpicking: you can create CONV with `{0,1}{0,1}...` as well. – karakfa Feb 05 '16 at 22:27

Bash script to convert decimal IP to binary

1 Answers1