PASSWD(1)                                                            PASSWD(1)



NAME
       chfn, chsh, passwd - change password file information

SYNOPSIS
       passwd [ -f ] [ -s ] [ name ]

DESCRIPTION
       This command changes (or installs) a password, login shell (-s option),
       or GECOS information field (-f option) associated with  the  user  _n_a_m_e
       (your own name by default).

       When  altering a password, the program prompts for the current password
       and then for the new one.  The caller must supply both.  The new  pass‐
       word must be typed twice to forestall mistakes.

       New  passwords must be at least four characters long if they use a suf‐
       ficiently rich alphabet and at least six characters long  if  monocase.
       These rules are relaxed if you are insistent enough.

       Only the owner of the name or the super-user may change a password; the
       owner must prove he knows the old password.

       When altering a login shell, _p_a_s_s_w_d displays the  current  login  shell
       and  then  prompts for the new one.  The new login shell must be one of
       the approved shells listed in _/_e_t_c_/_s_h_e_l_l_s unless  you  are  the  super-
       user.  If _/_e_t_c_/_s_h_e_l_l_s does not exist, the only shells that may be spec‐
       ified are _/_b_i_n_/_s_h and _/_b_i_n_/_c_s_h.

       The super-user may change anyone’s login shell; normal users  may  only
       change their own login shell.

       When  altering the GECOS information field, _p_a_s_s_w_d displays the current
       information, broken into fields, as interpreted by the  _f_i_n_g_e_r(1)  pro‐
       gram, among others, and prompts for new values.  These fields include a
       user’s ‘‘real life’’ name, office room number, office phone number, and
       home  phone  number.  Included in each prompt is a default value, which
       is enclosed between brackets.  The default value is accepted simply  by
       typing  a  carriage  return.  To enter a blank field, the word ‘‘none’’
       may be typed.  Below is a sample run:

              Name [Biff Studsworth II]:
              Room number (Exs: 597E or 197C) []: 521E
              Office Phone (Ex: 1632) []: 1863
              Home Phone (Ex: 987532) [5771546]: none


       _P_a_s_s_w_d allows phone numbers to be entered with or without hyphens.   It
       is  a  good  idea to run _f_i_n_g_e_r after changing the GECOS information to
       make sure everything is setup properly.

       The super-user may change anyone’s GECOS information; normal users  may
       only change their own.

FILES
       /etc/passwd    The file containing all of this information
       /etc/shells    The list of approved shells

SEE ALSO
       login(1), finger(1), passwd(5), crypt(3)
       Robert Morris and Ken Thompson, _U_N_I_X _p_a_s_s_w_o_r_d _s_e_c_u_r_i_t_y



4th Berkeley Distribution        June 5, 1986                        PASSWD(1)