NAME
     passwd - modify a user's password

SYNOPSIS
     passwd [-l] [user]

DESCRIPTION
     The passwd utility changes the user's password.  First, the user is
     prompted for their current password.  If the current password is correct-
     ly typed, a new password is requested.  The new password must be entered
     twice to avoid typing errors.

     The new password should be at least six characters long and not purely
     alphabetic.  Its total length must be less than _PASSWORD_LEN (currently
     128 characters).  Numbers, upper case letters and meta characters are en-
     couraged.

     For domestic systems which have the Kerberos package installed, once the
     password has been verified, passwd communicates the new password informa-
     tion to the Kerberos authenticating host.

     -l    This option causes the password to be updated only in the local
           password file, and not with the Kerberos database.  When changing
           only the local password, pwd_mkdb(8) is used to update the password
           databases.  For systems without Kerberos this option is the de-
           fault.

     To change another user's Kerberos password, one must first run kinit(1)
     followed by passwd(1).  The super-user is not required to provide a us-
     er's current password if only the local password is modified.

     When changing the local password (as opposed to the Kerberos password)
     the passwd utility checks two entries from the login.conf(5) database.
     The boolean entry widepasswords indicates that the new wide password for-
     mat should be used (up to 128 characters are part of the password, verses
     only 8 characters in the traditional format).  The numeric entry
     minpasswordlen will specify the minimum length a password may be.  See
     login.conf(5) for information on setting these variables.

FILES
     /etc/master.passwd  The user database
     /etc/passwd         A Version 7 format password file
     /etc/passwd.XXXXXX  Temporary copy of the password file

SEE ALSO
     chpass(1),  kerberos(1),  kinit(1),  login.conf(5),  passwd(5),
     kpasswdd(8),  login(8),  pwd_mkdb(8),  vipw(8)

     Robert Morris, and Ken Thompson, UNIX password security.

HISTORY
     A passwd command appeared in Version 6 AT&T UNIX.