Check domain expires days

whois_domain_expire.sh

#!/usr/bin/env bash

#
# Program: Check domain expires days <whois_domain_expire.sh>
#
# Author: Mikhail Grigorev <sleuthhound at gmail dot com>
# 
# Current Version: 1.0.2
#
# License:
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
#

URL=$1

_usage() {
	echo ""
	echo "Usage: $0 domain.com"
	echo ""
	exit 1
}

[ $# -eq 0 ] && _usage

nslookup "${URL}" >/dev/null 2>&1

if [ $? -eq 0 ]; then
	TODAY=$(date '+%Y-%m-%d')
	DOMAIN=$(whois "${URL}" 2>/dev/null | egrep -i "Expires.*:|Expiration.*:|Renewal.*:|expir.*date:|paid-till:" | head -n 1 | cut -d: -f2- | sed -e's/^[ ]*//' | sed 's/^[ \t]*//;s/[ ]*$//')
	DOMAIN_EXPIRES=$(( ($(date -d "${DOMAIN}" "+%s" 2>/dev/null) - $(date -d "${TODAY}" "+%s" 2>/dev/null) ) / 86400 ))

	if ! [[ "${DOMAIN_EXPIRES}" =~ ^[0-9]+$ ]]; then
		DOMAIN_EXPIRES=0
	fi

	if [ -n "${DOMAIN_EXPIRES}" ]; then
		echo -n "${DOMAIN_EXPIRES}"
	else
		echo -n "0"
	fi
else
	echo -n "0"
fi

exit 0