shell 通过IP 掩码 获取网络号

#! /bin/sh
#!/bin/bash
ETH0_MASK=$(ifconfig eth0 | grep "inet addr:" | awk -F " " '{print $4}' | awk -F ":" '{print $2}')
ETH0_IP=$(ifconfig eth0 | grep "inet addr:" | awk -F " " '{print $2}' | awk -F ":" '{print $2}')
WLAN0_MASK=$(ifconfig wlan0 | grep "inet addr:" | awk -F " " '{print $4}' | awk -F ":" '{print $2}')
WLAN0_IP=$(ifconfig wlan0 | grep "inet addr:" | awk -F " " '{print $2}' | awk -F ":" '{print $2}')


get_netdes()
{
ip1=$(echo $1 | awk -F "." '{print $1}')
ip2=$(echo $1 | awk -F "." '{print $2}')
ip3=$(echo $1 | awk -F "." '{print $3}')
ip4=$(echo $1 | awk -F "." '{print $4}')
echo $ip1 $ip2 $ip3 $ip4
mask1=$(echo $2 | awk -F "." '{print $1}')
mask2=$(echo $2 | awk -F "." '{print $2}')
mask3=$(echo $2 | awk -F "." '{print $3}')
mask4=$(echo $2 | awk -F "." '{print $4}')
echo $mask1 $mask2 $mask3 $mask4

var=1
var=$[$var+1]
gate1=$(($ip1&$mask1))
gate2=$(($ip2&$mask2))
gate3=$(($ip3&$mask3))
gate4=$(($ip4&$mask4))
echo $gate1 $gate2 $gate3 $gate4
}


get_gateway $ETH0_IP $ETH0_MASK