Проверка доступности порта без telnet

chk-port.sh

#!/bin/bash
HOST=$1
PORT=$2
if (echo > /dev/tcp/"$HOST"/"$PORT") > /dev/null 2>&1
then
    echo "$HOST $PORT [ OK ]"
else
    echo "$HOST $PORT [ ERROR ]"
fi
exit 0

---

~ > $ ./chk-port.sh 192.168.1.1 80
192.168.1.1 80 [ OK ]
~ > $ ./chk-port.sh 192.168.1.1 8090
192.168.1.1 8090 [ ERROR ]