dobroho_vechora/dobroho_vechora.bash

#!/bin/bash
set -e
ip="${1}"
port="${2}"

print_usage() {
	echo "${1}"
	echo "${0} <IP> <PORT>"
	exit
}
[ -z "${ip}" ]   && print_usage 'No IP given.'
[ -z "${port}" ] && print_usage 'No port given.'
[ -z "${3}" ]    || print_usage 'Too many arguments.'

send_message() {
	exec 3<> "/dev/tcp/${ip}/${port}"
	echo "${1}" >&3
	exec 3>&-
}

get_message() {
	exec 3<> "/dev/tcp/${ip}/${port}"
	echo "${1}" >&3
	timeout 1s cat <&3 || true
	exec 3>&-
}

while :; do
	read cmd
	case "${cmd}" in
		i)
			b=""
			while :; do
				read c
				[[ "${c}" != "." ]] || break
				if [ -z ${b} ]; then
					b="${c}"
				else
					b="${b}"$'\n'"${c}"
				fi
			done
			send_message 0"${b}"
			;;
		I)
			read a
			send_message 0"${a}"
			;;
		p)
			send_message 1
			get_message 2 | sed -e 's/\x1B/ESC/g'
			;;
		q)
			exit
			;;
		*)
			echo ?
			;;
	esac
done