Provided by: passwd_4.1.4.2+svn3283-3ubuntu5_amd64 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).