You would only use chage to modify existing accounts, and you would use it for setting either an account expiration or a password expiration. Here are the relevant option switches:
| Option |
Explanation |
| -d |
If you use the -d 0 option on someone's account, you'll force the user to change his or her password on their next login. |
| -E |
This is equivalent to the lowercase -e for useradd or usermod. It sets the expiration date for the user account. |
| -I |
This is equivalent to -f for useradd or usermod. It sets the number of days before an account with an expired password will be locked out. |
| -m |
This sets the minimum number of days between password changes. In other words, if Charlie changes his password today, the -m 5 option will force him to wait five days before he can change his password again. |
| -M |
This... |
