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

NAZWA

       pwck - verify integrity of password files

STRESZCZENIE

       pwck [-q] [-s] [passwd [ shadow ]]

       pwck [-q] [-r] [passwd [ shadow ]]

OPIS

       The pwck command verifies the integrity of the users and authentication information. It
       checks that all entries in /etc/passwd and /etc/shadow have the proper format and contain
       valid data. The user is prompted to delete entries that are improperly formatted or which
       have other uncorrectable errors.

       Checks are made to verify that each entry has:

       ·   the correct number of fields

       ·   a unique and valid user name

       ·   a valid user and group identifier

       ·   a valid primary group

       ·   a valid home directory

       ·   a valid login shell

       shadow checks are enabled when a second file parameter is specified or when /etc/shadow
       exists on the system.

       These checks are the following:

       ·   every passwd entry has a matching shadow entry, and every shadow entry has a matching
           passwd entry

       ·   passwords are specified in the shadowed file

       ·   shadow entries have the correct number of fields

       ·   shadow entries are unique in shadow

       ·   the last password changes are not in the future

       The checks for correct number of fields and unique user name are fatal. If the entry has
       the wrong number of fields, the user will be prompted to delete the entire line. If the
       user does not answer affirmatively, all further checks are bypassed. An entry with a
       duplicated user name is prompted for deletion, but the remaining checks will still be
       made. All other errors are warning and the user is encouraged to run the usermod command
       to correct the error.

       The commands which operate on the /etc/passwd file are not able to alter corrupted or
       duplicated entries.  pwck should be used in those circumstances to remove the offending
       entry.

OPCJE

       Polecenie pwck posiada następujące opcje:

       -q
           Report errors only. The warnings which do not require any action from the user won't
           be displayed.

       -r
           Execute the pwck command in read-only mode.

       -s
           Sort entries in /etc/passwd and /etc/shadow by UID.

       By default, pwck operates on the files /etc/passwd and /etc/shadow. The user may select
       alternate files with the passwd and shadow parameters.

CONFIGURATION

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

       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.

PLIKI

       /etc/group
           Informacje o grupach użytkowników.

       /etc/passwd
           Informacja o kontach użytkowników.

       /etc/shadow
           Informacje chronione o użytkownikach.

KOD ZAKOŃCZENIA

       Polecenie pwck kończy działanie z następującymi wartościami kodów zakończenia:

       0
           poprawne zakończenie działania programu

       1
           niepoprawna składnia polecenia

       2
           one or more bad password entries

       3
           can't open password files

       4
           can't lock password files

       5
           can't update password files

       6
           can't sort password files

ZOBACZ TAKŻE

       group(5), grpck(8), passwd(5), shadow(5), usermod(8).