Provided by: passwd_4.1.1-6ubuntu6_i386 bug

NOME

       pwconv, pwunconv, grpconv, grpunconv - convertono a e da password e
       gruppi shadow.

SINOSSI

       pwconv

       pwunconv

       grpconv

       grpunconv

DESCRIZIONE

       The pwconv command creates shadow from passwd and an optionally
       existing shadow.

       The pwunconv command creates passwd from passwd and shadow and then
       removes shadow.

       The grpconv command creates gshadow from group and an optionally
       existing gshadow.

       The grpunconv command creates group from group and gshadow and then
       removes gshadow.

       Questi quattro programmi agiscono tutti sui file normali e oscurati
       (shadow) delle password e dei gruppi: /etc/passwd, /etc/group,
       /etc/shadow e /etc/gshadow.

       Ciascun programma, prima della conversione, acquisisce i lock
       necessari.  pwconv e grpconv sono simili. Per prima cosa vengono
       rimosse le voci nel file oscurato che non esistono nel file principale.
       Quindi vengono aggiornate le voci oscurate che non hanno ‘x´ come
       password nel file principale. Vengono aggiunte le eventuali voci
       oscurate mancanti. Infine, le password nel file principale vengono
       sostituite con ‘x´. Questi programmi possono essere usati per le
       conversioni iniziali così come per aggiornare il file oscurato se il
       file principale viene editato a mano.

       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
       /etc/shadow.

       Analogamente, pwunconv e grpunconv sono simili. Le password nel file
       principale vengono aggiornate dal file oscurato. Voci che esistono nel
       file principale ma non nel file oscurato vengono lasciate stare.
       Infine, viene rimosso il file oscurato.Alcune informazioni
       sull´invecchiamento delle password vengono perse da pwunconv.
       Convertirà solo quello che potrà.

PROBLEMI

       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.

CONFIGURATION

       The following configuration variable in /etc/login.defs changes the
       behavior of grpconv and grpunconv:

       MAX_MEMBERS_PER_GROUP (number)
           Maximum members per group entry. When the maximum is reached, a new
           group entry (line) is started in /etc/group (with the same name,
           same password, and same GID).

           The default value is 0, meaning that there are no limits in the
           number of members in a group.

           This feature (split group) permits to limit the length of lines in
           the group file. This is useful to make sure that lines for NIS
           groups are not larger than 1024 characters.

           If you need to enforce such limit, you can use 25.

           Note: split groups may not be supported by all tools (even in the
           Shadow toolsuite. You should not use this variable unless you
           really need it.

       The following configuration variables in /etc/login.defs change the
       behavior of pwconv:

       PASS_MAX_DAYS (number)
           The maximum number of days a password may be used. If the password
           is older than this, a password change will be forced. If not
           specified, -1 will be assumed (which disables the restriction).

       PASS_MIN_DAYS (number)
           The minimum number of days allowed between password changes. Any
           password changes attempted sooner than this will be rejected. If
           not specified, -1 will be assumed (which disables the restriction).

       PASS_WARN_AGE (number)
           The number of days warning given before a password expires. A zero
           means warning is given only upon the day of expiration, a negative
           value means no warning is given. If not specified, no warning will
           be provided.

FILE

       /etc/login.defs
           Shadow password suite configuration.

VEDERE ANCHE

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