PASSWD(1)                    General Commands Manual                   PASSWD(1)

     passwd – modify a user's password

     passwd [-i infosystem [-l location]] [-u authname] [user]

     The passwd utility changes the user's password.  If the user is not the
     super-user, passwd first prompts for the current password and will not
     continue unless the correct password is entered.

     When entering the new password, the characters entered do not echo, in
     order to avoid the password being seen by a passer-by.  The passwd utility
     prompts for the new password twice in order to detect typing errors.

     The new password should be at least six characters long and not purely
     alphabetic.  Its total length should be less than _PASSWORD_LEN (currently
     128 characters), although some directory systems allow longer passwords.
     Numbers, upper case letters, and meta characters are encouraged.

     Once the password has been verified, passwd communicates the new password
     to the directory system.

     -i infosystem
           This option specifies where the password update should be applied.
           Under Mac OS X 10.5 and later, supported directory systems are:

           PAM   (default) Pluggable Authentication Modules.

                 A system conforming to Open Directory APIs and supporting
                 updates (including LDAP, etc).  If no -l option is specified,
                 the search node is used.

           file  The local flat-files (included for legacy configurations).

           nis   A remote NIS server containing the user's password.

     -l location
           This option causes the password to be updated in the given location
           of the chosen directory system.

           for file,
                 location may be a file name (/etc/master.passwd is the default)

           for nis,
                 location may be a NIS domainname

           for opendirectory,
                 location may be a directory node name

           for PAM,
                 location is not used

     -u authname
           This option specifies the user name to use when authenticating to the
           directory node.

     user  This optional argument specifies the user account whose password will
           be changed.  This account's current password may be required, even
           when run as the super-user, depending on the directory system.

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

     chpass(1), dscl(1), login(1), passwd(5), pwd_mkdb(8), vipw(8)

     Robert Morris and Ken Thompson, UNIX password security.

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

macOS                            August 18, 2008                           macOS