'MeetInLeeds' Wi-Fi login script for 'University of Leeds'

MeetInLeedsLogin.sh

#!/bin/sh

usage() {
        if [ $1 == 1 ]; then
                echo "MeetInLeeds Wi-Fi Login"
				echo "Author: XFY9326"
				echo "Website: https://xfy9326.github.io"
                echo ""
        fi
        echo "Options:"
        echo "-u\t\tUser name (Not full email address)"
        echo "-p\t\tUser password"
}

while getopts u:p::h options; do
        case "${options}" in
                u) USER_NAME=${OPTARG};;
                p) USER_PASSWORD=${OPTARG};;
                h) usage 1; exit 0;;
                \?) usage 0; exit 1;;
        esac
done

if [ $OPTIND == 1 ]; then
   usage 1
   exit 0
fi

if [ "$USER_NAME" == "" ]; then
        echo "Missing username!"
        exit 2
fi
if [ "$USER_PASSWORD" == "" ]; then
        echo "Missing password!"
        exit 3
fi

echo "User: $USER_NAME"

USER_EMAIL="$USER_NAME%40leeds.ac.uk"

LOGIN_HOST="uolwrd.leeds.ac.uk"
CAPTIVE_PORTAL_REDIRECT="captive.apple.com"

LOGIN_SUCCESS_STR="login_success_noContent.html"
ALREADY_LOGIN_STR="wlan=MeetInLeeds&statusCode=1"

if curl --output /dev/null --head --insecure -s "$LOGIN_HOST"; then
        echo "Start Login ... ..."
else
        echo "Can't find login server!"
        exit 5
fi

LOGIN_RESULT=$(curl --insecure -s "https://$LOGIN_HOST/login.html" --data-raw "username=$USER_EMAIL&password=$USER_PASSWORD&buttonClicked=4&redirect_url=$CAPTIVE_PORTAL_REDIRECT&err_flag=0&info_flag=0&info_msg=0")
RESULT_SUCCESS=$(echo "$LOGIN_RESULT"|grep $LOGIN_SUCCESS_STR)
RESULT_ALREADY_LOGIN=$(echo "$LOGIN_RESULT"|grep $ALREADY_LOGIN_STR)

if [ "${RESULT_SUCCESS}"x != ""x ] ; then
        echo "MeetInLeeds login success!"
        exit 0
elif [ "${RESULT_ALREADY_LOGIN}"x != ""x ] ; then
        echo "MeetInLeeds already Login!"
        exit 9
else
        echo "MeetInLeeds login failed!"
        exit 10
fi