check ssl cert expiration

chkssl.sh

#!/bin/bash                                                                                                                                
                                                                                                                                           
DAYS=30                                                                                                                                    
RECIPIENT="username@email.com"                                                                                                              
                                                                                                                                           
while read TARGET                                                                                                                          
do
if [ -z "$TARGET" ];then continue; fi

                                                                                                                                           
sslexpiredate=$(date +%s -d "$(:|openssl s_client -connect $TARGET:443 2>/dev/null | \                                                     
                                openssl x509 -noout -enddate|\                                                                             
                                awk -F'=' '{print $2}')");                                                                                 
notafterdate=$(($(date +%s) + (86400*$DAYS)));                                                                                             
                                                                                                                                           
if [ $notafterdate -gt $sslexpiredate ]; then                                                                                              
 echo "ssl of $TARGET will expire less than $DAYS" | \                                                                                     
        mailx -s "SSL expiring notice" $RECIPIENT;                                                                                         
else                                                                                                                                       
 echo "OK - $TARGET"                                                                                                                       
fi;                                                                                                                                        
                                                                                                                                           
done <$1