PWCONV(8)                 System Management Commands                 PWCONV(8)

NAME
       pwconv, pwunconv, grpconv, grpunconv - convert between the system's
       shadowed and plain account files

UBERSICHT
       pwconv [options]

       pwunconv [options]

       grpconv [options]

       grpunconv [options]

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

       The pwunconv command creates a plain passwd from shadowed passwd and
       shadow and then removes shadow.

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

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

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

       Each program acquires the necessary locks before conversion.  pwconv
       and grpconv are similar. First, entries in the shadowed file which
       don't exist in the plain file are removed. Then, entries in the
       shadowed file which don't have `x' as the password in plain file are
       updated. Any missing shadowed entries are added. Finally, passwords in
       the plain file are replaced with `x'. These programs can be used for
       initial conversion as well to update the shadowed file if the plain
       file has been edited by hand.

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

       Likewise pwunconv and grpunconv are similar. Passwords in the plain
       file are updated from the shadowed file. Entries which exist in the
       plain 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.

OPTIONEN
       The options which apply to the pwconv, pwunconv, grpconv, and grpunconv
       commands are:

       -h, --help
           zeigt die Hilfe an und beendet das Programm.

       -R, --root CHROOT_DIR
           Apply changes in the CHROOT_DIR directory and use the configuration
           files from the CHROOT_DIR directory. Only absolute paths are
           supported. No SELINUX support.

FEHLER
       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 shadowed files.

KONFIGURATION
       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).

           Der Standardwert ist 0, was bedeutet, dass die Anzahl der
           Mitglieder einer Gruppe nicht begrenzt ist.

           Das Aufteilen von Gruppen ermoglicht es, Langenvorgaben fur die
           Zeilen der Gruppendatei einzuhalten. Damit kann sichergestellt
           werden, dass die Zeilen fur NIS-Gruppen nicht langer als 1024
           Zeichen sind.

           Falls Sie eine solche Begrenzung benotigen, konnen Sie 25
           verwenden.

           Hinweis: Mit aufgeteilten Gruppen konnen moglicherweise nicht alle
           Hilfsprogramme (nicht einmal jene der Shadow-Programmsammlung)
           umgehen. Sie sollten diese Variable nur setzen, wenn Sie sie
           wirklich benotigen.

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

       PASS_MAX_DAYS (number)
           die maximale Anzahl von Tagen, die ein Passwort verwendet werden
           darf. Wenn das Passwort alter ist, wird ein Wechsel des Passworts
           erzwungen. Falls nicht definiert, wird -1 angenommen, womit
           Passworter unbefristet gelten.

       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 value of
           -1 means no warning is given. If not specified, no warning will be
           provided.

DATEIEN
       /etc/login.defs
           konfiguriert die Shadow-Hilfsprogramme.

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

shadow-utils 4.20.0               30.07.2026                         PWCONV(8)