PASSWD(1)                            SysV                            PASSWD(1)



NAME
     passwd - change login password

SYNOPSIS
     passwd [ name ]

DESCRIPTION
     This command changes or installs a password associated with a login name.
     You can change your own password and the password of the accounts you
     own.

     passwd prompts users for their old password, if any.  It then prompts for
     the new password twice.   A check is made to ensure that the new password
     meets construction requirements.  When the new password is entered a
     second time, the two copies of the new password are compared.  If the two
     copies are not identical, the cycle of prompting for the new password is
     repeated for, at the most, two more times.

LOCAL CUSTOMIZATION VS. NETWORK REGISTRY CHANGES
     passwd command options let you you specify whether the change should
     affect the network registry or only the local password override file.
     These command options are:

     ⊕ -n -- The password should be changed only in the network registry.

     ⊕ -l -- The password should be changed only on the local machine. In
       other words, the change is a local customization.  The command will not
       change the network registry; it will change only the local password
       override file.

     Note that you cannot change another user's password overrides unless you
     are root.

Option Defaults
     If you do not specify either option, passwd updates the network registry
     if, and only if, the target of the command is not being overridden for
     that machine.  If the target is overridden, all commands exit with an
     informative message.

     For example, assume your password is overridden.  If you run the passwd
     command to change it without specifying either the -l or -n command, the
     following sequence occurs:

          $ passwd
          Your password is tailored for this machine.
          Use 'passwd -n' to modify the registry.
          Use 'passwd -l' to modify the local customization database.


Example: Overridding a Local Password
     The following example shows the sequence that occurs if you specify the
     -l option with the passwd command.

          $ passwd -l
          Changing local password for tech.sales.usa
          Please enter your password:
          New local password for tech.sales.usa:
          Retype new local password:


Example: Overridding Network Information

     The following example shows the sequence that occurs if you specify the
     -n option with the passwd command.

          $ passwd -n
          Changing network password for tech.sales.usa
          Please enter your password:
          New network password for tech.sales.usa:
          Retype new network password:


PASSWORD CONSTRUCTION REQUIREMENTS
     Passwords must meet the following construction requirements:

     ⊕ Passwords must be between six and eight characters long, inclusive.

     ⊕ Passwords must contain at least two alphabetic characters (upper or
       lower case) and at least one numeric or special character.

     ⊕ Passwords must differ from the user's login name and any reverse or
       circular shift of that login name.  For comparison purposes, an
       uppercase letter and its corresponding lowercase letter are equivalent.

     ⊕ New passwords must differ from the old by at least three characters.
       For comparision purposes,  an uppercase letter and its corresponding
       lowercase letter are equivalent.

SUPER-USERS
     A user with a user ID of zero is a super-user;  see id(1) and su(1).
     Super-users can change any password.  passwd, therefore, does not prompt
     super-users for the old password.  Super-users are also not forced to
     comply with password construction requirements.  A super-user can create
     a null password by entering a carriage return in response to the prompt
     for a new password.

SEE ALSO
     login(1), crypt(3C), passwd(4), su(1), passwd_override(5).