shell 获得本机IP和free端口

#!/bin/bashIPaddr=`ifconfig | grep inet\\\\s | grep -v "127.0.0." | sed "s/addr://g"| awk '{print $2}'`function getfreeport(){    IPaddr=$1    first=$2    last=$3    for (( port = $first; port <= ${last}; port++ ))        do            (echo > /dev/tcp/$IPaddr/$port) &> /dev/null            if [ $? != 0 ]            then                 echo $port                 break            fi        done}port=$(getfreeport $IPaddr 22 100)echo "free port=${port}"