Get all ip address from subnet mask

Shell Programming and Scripting
1

I have this subnet file shown below. How can I calculate all ip addresses from that list

103.22.200.0/22 
141.101.64.0/18
10.0.0.0/22

I need to be able to read the subnet file and print all IPs in those subnet to an out put file

2

There will be thousands and thousands. Just comparing would be simpler and more effective than generating an exhaustive list.

3

Let say we have a subnet file that has 2 line

10.10.0.0/26
11.00.00.0/26

How would you list those ips in those subnets?

4

It'd make sense to compare instead of printing a comprehensive list. Subnets work the way they do because it's very easy to compare an IP to a subnet and mask with logical operations.

But if you insist I'll show you a way. It requires a 3.0+ BASH shell.

#!/bin/bash

printsubnet() {
        local OLDIFS="$IFS"
        local SUB=${1/\/*/}
        local MASK=$(( 1 << ( 32 - ${1/*\//} )))

        IFS="."
                set -- $SUB
                IPS=$((0x$(printf "%02x%02x%02x%02x\n" $1 $2 $3 $4)))
        IFS="$OLDIFS"

        for ((N=0; N<MASK; N++))
        {
                VAL=$((IPS|N))

                printf "%d.%d.%d.%d\n"                  \
                        $(( (VAL >> 24) & 255 ))        \
                        $(( (VAL >> 16) & 255 ))        \
                        $(( (VAL >> 8 ) & 255 ))        \
                        $(( (VAL)       & 255 ))
        }
}

printsubnet 172.16.0.0/16