如果IP/端口关闭，则Bash检查

Question

我试图通过netstat使用bash脚本检查IP/端口的状态。不幸的是它行不通..。我得到一个出口1，即使它应该是0出口。

RUNBOT=$(netstat -tulpen |grep ${IP}:${PORT} | wc -l)

    if [ "${RUNBOT} = "1" ]; then
            echo "Bot ${IP}:${PORT} is running!"        
        exit 0
    else
            echo "Bot ${IP}:${PORT} is NOT running!"
        exit 1
    fi

Answer 1

lsof -ni @${IP}:${PORT} >/dev/null
b=$?
if [ $b = 0 ]; then
            echo "Bot ${IP}:${PORT} is running!"        
        exit 0
    else
            echo "Bot ${IP}:${PORT} is NOT running!"
        exit 1
fi