passwd(1)                           CLIX                           passwd(1)



  NAME

    passwd - Changes login password

  SYNOPSIS

    passwd [name]

  DESCRIPTION

    The passwd command changes or installs a password associated with the
    login name.  Ordinary users may change only the password which corresponds
    to their login name.

    The passwd command 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 lowercase 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
       uppercase letter and its corresponding lowercase letter are equivalent.

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

    One whose effective user ID is zero is called a superuser; see id, and su.
    Superusers may change any password; hence, passwd does not prompt
    superusers for the old password.  Superusers are not forced to comply with
    password aging and password construction requirements.  A superuser can
    create a null password by entering a carriage return in response to the
    prompt for a new password.



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  passwd(1)                           CLIX                           passwd(1)



    A password containing an "*" is locked.

  EXAMPLES

    The following is an example of a password session:

    $ passwd


    Old password:

    Enter the old password at this point.  It will not be echoed.

    New password:

    Enter the new password, which also will not be echoed.

    New password:

    Enter the new password again.

  FILES

    /etc/passwd

  DIAGNOSTICS

    Sorry. The old password was entered incorrectly.

    Too many tries; try again later.
           The password could not be verified after three tries.

    Cannot read input from terminal.
           The passwd program could not open a terminal from which to read
           input.  For example, this can happen during a remote command
           execution using rcmd(1).

  EXIT VALUES

    The passwd command exits with a value of 0 if successful and a value of 1
    if unable to change the password.

  RELATED INFORMATION

    Commands: login(1), id(8), su(8)

    Functions: crypt(3)

    Files: passwd(4)





  2                                              Intergraph Corporation - 2/94