How to Manage Linux Users expiration or aging settings

As system admin on Linux and Unix bases systems is very important that you have a good knowledge on how to manage and deal with your Users password expiration or aging settings.
The utility that i prefer for this task is called chage.
The chage command changes the number of days between password changes and the date of the last password change. This information is used by the system to determine when a user must change his/her password.
Options and syntax of the chage command: 

[aodba]$ chage --help Usage: chage [options] user Options: -d, --lastday LAST_DAY set last password change to LAST_DAY -E, --expiredate EXPIRE_DATE set account expiration date to EXPIRE_DATE -h, --help display this help message and exit -I, --inactive INACTIVE set password inactive after expiration to INACTIVE -l, --list show account aging information -m, --mindays MIN_DAYS set minimum number of days before password change to MIN_DAYS -M, --maxdays MAX_DAYS set maximim number of days before password change to MAX_DAYS -W, --warndays WARN_DAYS set expiration warning days to WARN_DAYS

• To list current aging type chage command as follows:

[aodba]$ chage -l adrian.oprea Last password change : Jul 22, 2014 Password expires : Oct 20, 2014 Password inactive : never Account expires : never Minimum number of days between password change : 1 Maximum number of days between password change : 90 Number of days of warning before password expires : 7

Let’s see how we can alter this definitions

How to alter the “Maximum number of days between password change”

[root@aodba ~]# chage -M 160 adrian.oprea --verify the definition [root@aodba ~]# chage -l adrian.oprea Last password change : Jul 22, 2014 Password expires : Dec 29, 2014 Password inactive : never Account expires : never Minimum number of days between password change : 1 Maximum number of days between password change : 160 Number of days of warning before password expires : 7

How to alter the “Number of days of warning before password expires”

[root@aodba ~]# chage -W 3 adrian.oprea --verify the definition [root@aodba ~]# chage -l adrian.oprea Last password change : Jul 22, 2014 Password expires : Dec 29, 2014 Password inactive : never Account expires : never Minimum number of days between password change : 1 Maximum number of days between password change : 160 Number of days of warning before password expires : 3

Also we we can do this on single line

[root@aodba ~]# chage -W 3 -M 160 adrian.oprea --verify the definition [root@aodba ~]# chage -l adrian.oprea Last password change : Jul 22, 2014 Password expires : Dec 29, 2014 Password inactive : never Account expires : never Minimum number of days between password change : 1 Maximum number of days between password change : 160 Number of days of warning before password expires : 3