passwd changes authentication information for user and group accounts, including passwords and password expiry details, and may be used to enable and disable accounts. Only a user with appropriate privilege may change the password for other users or modify the expiry information.
sets the maximum number of days a password remains valid.
sets the minimum number of days before a password may be changed.
sets the number of days warning the user will receive before their password will expire.
disables an account after the password has been expired for the given number of days.
disables an account by changing the password to a value which matches no possible encrypted value.
re-enables an account by changing the password back to its previous value.