irc post script with a single message.

irc.sh

#!/bin/sh

if [ $# -ne 4 ]; then
    echo "usage: <server> <nick> <channel> <message>"
    echo "ex: irc.example.com bot #chatroom hello"
    exit
fi

SERVER=$1
PORT=6667
NICK=$2
CHANNEL=$3
MESSAGE=$4
HOSTNAME=$(hostname -f)

cat << __IRC__ | telnet $SERVER $PORT
NICK $NICK
USER $NICK $HOSTNAME $HOSTNAME $NICK
JOIN $CHANNEL
NOTICE $CHANNEL $MESSAGE
QUIT
__IRC__