Red Hat Enterprise Linux 5 Administration Unleashed

210CHAPTER 9Managing Users and GroupsTABLE 9.2Command-Line OptionAdditional Options for Modifying UsersDescription-l Change the user’s username to . You shouldconsider changing the user’s home directory and name of the userprivate group to reflect username change.-L Lock the user’s password by placing the ! character in front of itin /etc/shadow or /etc/passwd. User can no longer log in to thesystem with the old password.-U Unlock the user’s password so the user can log in to the systemagain. Removes the ! character in front of it in /etc/shadow or/etc/passwd.Password AgingOptionally, password aging can also be configured with the chage command. If the chagecommand is immediately followed by a username, the administrator will be interactivelyprompted for the password aging values as shown in Listing 9.1. The command-lineoptions in Table 9.3 can also be used with chage.TIPTo list current password aging values, use the chage -l command.LISTING 9.1Interactive Password Aging ConfigurationChanging the aging information for testuserEnter the new value, or press ENTER for the defaultMinimum Password Age [0]:Maximum Password Age [99999]:Last Password Change (YYYY-MM-DD) [2006-02-12]:Password Expiration Warning [7]:Password Inactive [-1]:Account Expiration Date (YYYY-MM-DD) [1969-12-31]:TABLE 9.3 Command-Line Options for Password AgingCommand-Line Option Description-d Number of days since January 1, 1970 when the password waschanged or the date when the password was last changed in theformat YYYY-MM-DD.-E Number of days since January 1, 1970 on which the account willbe locked or the date on which the account will be locked in theformat YYYY-MM-DD.-I Number of inactive days since the password has expired before theaccount is locked. -1 disables this feature.