Zabbix Bash API Authentication

#!/bin/bash
ZABBIX_USER="admin"
ZABBIX_PASS="zabbix"
ZABBIX_API="http://demo.zabbixzone.com/trunk/api_jsonrpc.php"

authenticate()
{
    wget -O- -o /dev/null $ZABBIX_API --header 'Content-Type: application/json-rpc' --post-data "{\"jsonrpc\": \"2.0\",\"method\": \"user.login\",\"params\": {\"user\": \"$ZABBIX_USER\",\"password\": \"$ZABBIX_PASS\"},\"id\": 1}" | cut -d'"' -f8
}

AUTH_TOKEN=$(authenticate)

echo $AUTH_TOKEN