- Hello, I need to make sure I have the external or at least the main IP address for a given machine, regardless to the device type/name. I quickly wrote that tiny script for that purpose, but I need to know the drawbacks of such a script. And whether there is a better system call to get for sure the external IP address; if not, the main IP of the host. Furthermore, is there any other tool that serves that purpose?
- Subject Machines are mostly CentOS 5/6 , Gentoo 1/2
#!/bin/bash
#!/bin/bash #Author: Hanynowsky <[email protected]> COM1=$(dig +short myip.opendns.com @resolver1.opendns.com) COM2=$(hostname -i 2>/dev/null) COM3=$(ip route show 2>/dev/null | grep src | grep -vE 'eth1.*|lo' | awk -Fsrc '{print $2}' | sed -e 's/ //g') COM4=$(curl -s monip.org 2>/dev/null | grep -o -E '([0-9]+\.){3}[0-9]+') COM5=$(host `hostname -f 2>/dev/null` | awk -F[aA]ddress '{print $2}' | sed 's/ //g') COM6=$(for i in eth0 em1 bond0; do inf=`ip -4 addr show dev $i 2>/dev/null | grep inet -m1 | cut -d/ -f1 | awk '{ print $2}'`;if [[ "$inf" =~ [0-9][0-9]?* ]]; then echo "$inf";fi ;done) if [[ "$1" =~ local ]] ;then COM1=$COM3 fi if [[ "$1" =~ private ]] ;then COM1=$COM2 fi if [[ "$1" =~ host ]] ;then COM1=$COM5 fi IP='' validip() { local ip=$1 local stat=1 if [[ $ip =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then OIFS=$IFS IFS='.' ip=($ip) IFS=$OIFS [[ ${ip[0]} -le 255 && ${ip[1]} -le 255 && ${ip[2]} -le 255 && ${ip[3]} -le 255 ]] stat=$? fi if [ "$stat" -eq 0 ]; then echo $IP else echo $stat fi return $stat } if [ -n "${COM1}" ];then IP=${COM1} eval validip $IP exit fi if [ -n "${COM2}" ];then IP=${COM2} eval validip $IP exit fi if [ -n "${COM3}" ];then IP=${COM3} eval validip $IP exit fi if [ -n "${COM4}" ];then IP=${COM4} eval validip $IP exit fi if [ -n "${COM5}" ];then IP=${COM5} eval validip $IP exit fi if [ -n "${COM6}" ];then IP=${COM6} eval validip $IP exit fi exit 