Need to get mail , in advance of approx one week if password suppose to be expire

UNIX for Beginners Q & A
1

I am preparing script , if user's password needs to be expire in one week. script is running, but gives output in 0.
please help, if any one worked on it..

User details.

[root@localhost ~]# chage  -l natasha
Last password change                                    : Feb 09, 2020
Password expires                                        : Apr 01, 2020
Password inactive                                       : never
Account expires                                         : never
Minimum number of days between password change          : 40
Maximum number of days between password change          : 52
Number of days of warning before password expires       : 7

script -------

#!/bin/sh
SUBJECT="Information About User Password Expiration on "`date`""
MESSAGE="/tmp/user-expiry.txt"
MESSAGE1="/tmp/user-expiry-1.txt"
TO="abc@gmail.com"
echo "-------------------------------------------------" >> $MESSAGE1
echo "UserName  The number of days the password expires" >> $MESSAGE1
echo "-------------------------------------------------" >> $MESSAGE1
for usern in natasha
do
today=$(date +%s)
userexpdate=$(chage -l $usern | grep 'Password expires' |cut -d: -f2)
passexp=$(date -d "$userexpdate" "+%s")
exp=`expr \( $passexp - $today \)`
expday=`expr \( $exp / 86400 \)`
echo "$usern $expday" >> $MESSAGE
done
cat $MESSAGE | awk '$2 <= 10' >> $MESSAGE1
mail -s "$SUBJECT" "$TO" < $MESSAGE1

Output.........

root@localhost ~]# cat /tmp/user-expiry-1.txt
natasha 0
natasha 0
natasha 0
-------------------------------------------------
UserName  The number of days the password expires
-------------------------------------------------
natasha 0
natasha 0
natasha 0
natasha 0
2

Please tell us all which operating system you are working on and its version number.

3

This is rhel 7.7

4

Is there any idea ? how to get the notification.

5

I'm a bit surprised about your output - how come it containes seven lines "natasha 0" when looping across one single username only? And three lines of those above the header lines? Sure the tmp files are empty when running the script? What be the values of the variables (userexpdate, passexp, exp, expday) during the one loop? Run script with the -x option set, and post output.