How to force a user to change their password at the next login in linux?

[petulia3478]

# /usr/bin/chage -d 0 testuser

When the user testuser next logs in, after they enter their original password, they will be prompted to change it:

login as: testuser
[email protected]'s password:
You are required to change your password immediately (root enforced)
Last login: Mon Jul 20 14:18:08 2009 from unknown-00-aa-bb-cc-dd-ee.home
WARNING: Your password has expired.
You must change your password now and login again!
Changing password for user testuser.
Changing password for testuser
(current) UNIX password:
New UNIX password:
Retype new UNIX password:

After retyping the new password the second time, the login window will disappear. When opening a new putty session, the user will need to enter their new password to log in.