shell get external ip，Usage: curl -sS 'https://gist.githubusercontent.com/Anye/050c14aee0653d8d4e19536b28f15d5b/raw/get_outer_ip.sh' | bash

get_outer_ip.sh

#!/bin/bash

get_outer_ip() {
    ip_addr=$( curl -sS http://echoip.me/raw )
    if [[ ! "${ip_addr}" =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
        ip_addr=$( dig +short @resolver1.opendns.com myip.opendns.com )
        ip_addr=${ip_addr//\"/}
        if [[ ! "${ip_addr}" =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
            ip_addr=$( dig +short @ns1.google.com o-o.myaddr.l.google.com -t txt )
            if [[ ! "${ip_addr}" =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
                ip_addr=$( ip addr | grep 'state UP' -A2 | tail -n1 | awk '{print $2}' | cut -f 1  -d '/' )
            fi
        fi
    fi

    echo ${ip_addr}
}

echo $( get_outer_ip )