Linux User Password expiry Monitoring

:: Linux User Password Expiry Monitoring ::

STEP 1: Create one file using bellow command

#touch expiry.sh

copy the below code and paste in expiry.sh file

#!/bin/bash
# Check Password expiry of specified user
# Author: Ankam Ravi Kumar
# Date: 6th July 2015


function check_usage {
        if (( $# != 1 ))
        then
                echo "Usage: ./expiry.sh <username>"
        exit 3
        fi
}

function calculate_days_till_expiry {
        get_expiry_date=$(/usr/sbin/lchage -l $1 | grep 'Password Expires' | cut -d: -f2)
        #if [[ $get_expiry_date = 'Never' ]]
        if [ $get_expiry_date = 'Never' ];
        then
                echo "Host Name: `hostname` User: $1 Password never expires"
        exit 0
        elif
        password_expiry_date=`date -d "$get_expiry_date" "+%s"`
        current_date=$(date "+%s")
        diff=$(($password_expiry_date-$current_date))
        let DAYS=$(($diff/(60*60*24)))
        then
        if (($DAYS>=15 && $DAYS<=90))
        then
                echo "OK - Host Name: `hostname` User: $1 Password is $DAYS days from expiry"
        exit 0
        elif (($DAYS>=5 && $DAYS<=14))
        then
                echo "WARNING - Host Name: `hostname` User: $1 Password is $DAYS days from expiry" > /tmp/tempuser
                mail -s "WARNING - Host Name: `hostname` User: $1 Password is $DAYS days from expiry" aravikumar48@gmail.com,$1 < /tmp/tempuser
        exit 1
        elif (($DAYS>=0 && $DAYS<=4))
        then
                echo "CRITICAL - Host Name: `hostname` User: $1 Password is $DAYS days from expiry"
                mail -s "CRITICAL - Host Name: `hostname` User: $1 Password is $DAYS days from expiry" aravikumar48@gmail.com,$1 < /tmp/tempuser
        exit 2
        fi
fi
}

check_usage $1
calculate_days_till_expiry $1

WARNING: Replace email address with your email address before execute

STEP 2: Then create one more called passwdcheck.sh using below command

#touch passwdcheck.sh

then copy the below code and paste in passwdcheck.sh file

 #!/bin/bash
# Check All the existing users Password expiry status
# Author: Ankam Ravi Kumar
# Date: 6th July 2016

for line in `cat /etc/passwd | cut -d: -f1` ; do
sh expiry.sh $line
done

STEP3: Execute the above file  using sh 

# sh passwdcheck.sh

STEP4: Add user email address in the below file to sent alerts directly to user

#vi /etc/aliases

in Last line of above file add

root:      ADMINEMAIL@DOMAIN.COM

Save & Exit