http_post() {
	if [ $# != 2 ]; then
		echo "Usage: http_post <url> <data>" 1>&2
		return 255
	fi
	#curl "$1" --request POST --data-binary "$2"
	wget --no-verbose "$1" --post-data "$2"
}

get_ip_address() {
	if [ $# != 1 ]; then
		echo "Usage: get_ip_address <interface>" 1>&2
		return 255
	fi
	ifconfig "$1" | grep -Eo -m 1 'inet[ a-z:]+172\.20\.0\.[0-9]{3}' | sed -r 's/^inet[ a-z:]+//'
	return 0
}

set_hostname_from_interface() {
	HOSTNAME="`get_ip_address \"$1\"`"
	if [ -z "$HOSTNAME" ]; then
		printf "Cannot get IP address from interface '%s'\\n" "$1" 1>&2
		exit 1
	fi
}

load_config_file() {
	[ -f "$1" ] || return
	eval "`grep -Eo '^[A-Z0-9_]+=[-A-Za-z0-9_@" .:/\\]+' \"$1\"`"
}

handle_command_line_options() {
	while getopts i:I:n: c
	do case "$c" in
		i)
			INTERVAL="$OPTARG"
			;;
		I)
			INTERFACE="$OPTARG"
			;;
		n)
			HOSTNAME="$1"
			;;
		\?)
			printf "Usage: %s [-i <interval>] [-I <interface>] [-n <hostname>]\\n" "$0" 1>&2
			exit 255
			;;
	esac done
}
