script to discover if an IP address belongs to an IP range

Question

I'm new here. I'm working on a script that has to tell me if a giving IP address belongs to a IP range, using bash scripting. For example: starting from a big range like 10.103.240.0/20 I have to code a script in bash linux to discover if the ip 10.102.247.221 belongs to the range? I know that the HostMin is 10.103.240.1 and the HostMax 10.103.255.254 but i don't know how to implement the comparison. Do you have a suggestion please? I don't know where to start.

Thanks

Answer 1

This could work :

function checkInRange() {
 hostMin=$1
 hostMax=$2
 ip=$3

 for i in $(seq 4)
 do
   hMini=$(echo $hostMin | cut -d'.' -f$i)
   hMaxi=$(echo $hostMax | cut -d'.' -f$i)
   ipi=$(echo $ip | cut -d'.' -f$i)
   if [[ $ipi -gt $hMaxi || $ipi -lt $hMini ]]
   then
     echo "$ip not in $hostMin - $hostMax range"  
     return 1
   fi
 done
 echo "$ip in $hostMin - $hostMax range"  
 return 0
}

if [[ $(checkInRange $hostMin $hostMax $ip) -eq 0 ]] 
then
  # Do your stuff...
fi