PWCONV linux command manual

PWCONV(8)                                                      PWCONV(8)

       pwconv,  pwunconv,  grpconv,  grpunconv  -  convert to and from shadow
       passwords and groups.


       These four programs all operate on the normal and shadow password  and
       group files: /etc/passwd, /etc/group, /etc/shadow, and /etc/gshadow.

       pwconv  creates  shadow from passwd and an optionally existing shadow.
       pwunconv creates passwd  from  passwd  and  shadow  and  then  removes
       shadow.  grpconv creates gshadow from group and an optionally existing
       gshadow.  grpunconv creates group from  group  and  gshadow  and  then
       removes gshadow.

       Each program acquires the necessary locks before conversion.

       pwconv  and grpconv are similiar.  First, entries in the shadowed file
       which don't exist in  the  main  file  are  removed.   Then,  shadowed
       entries  which  don't  have  'x'  as the password in the main file are
       updated.  Any missing shadowed entries are added.  Finally,  passwords
       in  the  main  file are replaced with 'x'.  These programs can be used
       for initial conversion as well to update the shadowed file if the main
       file is edited by hand.

       pwconv  will  use  the  values  of  PASS_MIN_DAYS,  PASS_MAX_DAYS, and
       PASS_WARN_AGE  from  /etc/login.defs  when  adding  new   entries   to

       Likewise,  pwunconv and grpunconv are similiar.  Passwords in the main
       file are updated from the shadowed file.  Entries which exist  in  the
       main  file  but not in the shadowed file are left alone.  Finally, the
       shadowed file is removed.

       Some password aging information is lost by pwunconv.  It will  convert
       what it can.

       Errors  in  the  password or group files (such as invalid or duplicate
       entries) may cause these programs to loop forever  or  fail  in  other
       strange  ways.   Please  run pwck and grpck to correct any such errors
       before converting to or from shadow passwords or groups.

       login.defs(5), grpck(8), pwck(8)

                                 26 Sep 1997                        PWCONV(8)