08.Feb.09Unlocking a user account# passwd -u user Unlocks user's account. That is, lets user log in (a locked account is one prevented from logging in).
25.Jan.09Locking a user account# passwd -l user Locks user's account, that is, prevents user from logging in. Note: This option is available in Linux and Solaris. In Mac OS X, -l option means something different: # passwd -l location user Here, -l changes the password in location. Valid values are: file: a filename. Default is /etc/master.passwd netinfo: a domain name or server/tag pair nis: an NIS domain name opendirectory: a directory node name