Check the expiration date on the SSL certificate of the given site.

check-ssl-certificate-expiration.sh

#!/bin/bash

# -----------------------------------------------------------------------------------------
# Check the expiration date on the SSL certificate of the given site. Usate:
# 
#   $ ./check-ssl-certificate-expiration.sh www.google.com
#
#    🏵  Checking SSL certificate for https://www.google.com...
#
#        Expiration date: Apr  9 13:15:00 2019 GMT
#
# Taken from:
#  https://realguess.net/2016/10/11/a-cli-method-to-check-ssl-certificate-expiration-date/
# -----------------------------------------------------------------------------------------

SERVER=$1

echo
echo -e "\e[1;93m🏵  Checking SSL certificate for https://$SERVER...\e[0m"
echo
echo | openssl s_client -connect $SERVER:443 2> /dev/null | \
  openssl x509 -noout -enddate | \
  awk -P -F= '{print "   Expiration date: " $2}'
echo