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PASSWD(1)                  Linux Programmer's Manual                 PASSWD(1)

       passwd(1,5) - change password

       passwd(1,5) [ -o ] [ -q ] [ -v ] [ name [ password ]]
       passwd(1,5) -f [ arguments to chfn ]
       passwd(1,5) -s [ arguments to chsh ]

       Without arguments passwd(1,5) will change the password for the current user.
       First the user is asked for the old password, then prompted  twice  for
       the new password in(1,8) order to catch typing errors.

       The one and two argument forms may only be used by the superuser. Using
       the one argument form, the superuser may change the password  for  that
       user.   The  superuser is not asked for the users(1,5) old password, but the
       rules for proper passwords are also applied unless  the  -o  option  is
       used. The superuser may have legitimate reasons to choose a non-confor-
       mant password.

       The two argument form gives the user the password stated as the  second
       argument.  Note that this password will be visible to people doing `ps'
       or so.  Avoid this form.

       Giving an empty string(3,n) as the second argument erases the  password  for
       the user, but only in(1,8) combination with the -o option.

       Password changes may get logged using the syslog(2,3,5,3 Sys::Syslog)(3) facility, depending
       on compile-time defines (on by default).  If so, every change  will  be
       logged  at  a  low  level  as auth.notice, except for changing the root
       password with will be logged with auth.warning.

       -f, --fullname
              Change the user's full name  (the  GECOS  field  of  the  passwd(1,5)
              entry).   Invokes /usr/bin/chfn with the non-option command line

       -o, --force
              Turn off simplicity checks on the new password. This option  may
              only  be  used by the super user. This is intend to allow simple
              initial passwords given by the superuser.

       -s, --shell
              Change the user's shell by invoking /usr/bin/chsh with the  non-
              option command line arguments.

       -q, --quiet, --silent
              In this mode passwd(1,5) won't tell that the passwd(1,5) get's changed.

       -v, -V, --version
              Prints version(1,3,5) information and exits.

       The new password must fulfill these rules:

       o      be at least six characters long;

       o      must not be equal to the old password;

       o      must  contain  characters  out  of at least two of the following
              classes: upper and lower case letters, digits and  non  alphanu-
              meric characters;

       o      must  not  match  neither the username nor any word of the real-
              name, neither in(1,8) normal nor in(1,8) reverse  order,  neither  at  the
              beginning nor at the end.

       If  you  change  your  mind there is no escaping from this program.  It
       will insist on a new  password  until  killed  from  another  terminal.
       (This is caused by a bug in(1,8) getpass(3): it ignores signals.)

              The password file.

       chsh(1), chfn(1), syslog(2,3,5,3 Sys::Syslog)(3), syslog.conf(5), passwd(1,5)(8).

       Peter Orbaek (
       Martin  Schulze  (  with extensive rewriting and
       improving done.

Util-linux 2.6                 11 November 1996                      PASSWD(1)

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