PASSWD(1)                                               PASSWD(1)



     NAME
          passwd - change login password

     SYNOPSIS
          passwd [ name ]

     DESCRIPTION
          This command changes or installs a password associated with
          the login name.

          Ordinary users may change only the password which
          corresponds to their login name.

          passwd prompts ordinary users for their old password, if
          any.  It then prompts for the new password twice. The first
          time the new password is entered passwd checks to see if the
          old password has ``aged'' sufficiently. Password "aging" is
          the amount of time (usually a certain number of days) that
          must elapse between password changes.  If ``aging'' is
          insufficient the new password is rejected and passwd
          terminates;  see passwd(4).

          Assuming ``aging'' is sufficient, a check is made to insure
          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 most two more times.

          Passwords must be constructed to meet the following
          requirements:

               Each password must have at least six characters.  Only
               the first eight characters are significant.

               Each password must contain at least two alphabetic
               characters and at least one numeric or special
               character.  In this case, ``alphabetic'' means upper
               and lower case letters.

               Each password must differ from the user's login name
               and any reverse or circular shift of that login name.
               For comparison purposes, an upper case letter and its
               corresponding lower case letter are equivalent.

               New passwords must differ from the old by at least
               three characters.  For comparison purposes, an upper
               case letter and its corresponding lower case letter are
               equivalent.

          One whose effective user ID is zero is called a super-user;
          see id(1), and su(1).  Super-users may change any password;



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     PASSWD(1)                                               PASSWD(1)



          hence, passwd does not prompt super-users for the old
          password.  Super-users are not forced to comply with
          password aging and 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.

     FILES
          /etc/passwd

     SEE ALSO
          login(1).
          crypt(3C), passwd(4) in the Programmer's Reference Manual.
          id(1M), su(1M) in the System Administrator's Reference
          Manual.

     ORIGIN
          AT&T V.3






































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