NAMN

       pwck - verify the integrity of password files

SYNOPSIS

       pwck [options] [PASSWORDFILE [ SHADOWFILE ]]

BESKRIVNING

       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.

       Kontroller görs för att validera att varje post har:

       •   korrekt antal fält

       •   a unique and valid user name

       •   en giltig identifierare för användare och grupp

       •   en giltig primär grupp

       •   en giltig hemkatalog

       •   ett giltigt inloggningsskal

       Checks for shadowed password information are enabled when the second file parameter SHADOWFILE 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 warnings 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.

FLAGGOR

       The -r and -s options cannot be combined.

       The options which apply to the pwck command are:

       --badname
           Allow names that do not conform to standards.

       -h, --help
           Visa hjälpmeddelande och avsluta.

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

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

       -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.

       -s, --sort
           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:

FILER

       /etc/group
           Gruppkontoinformation.

       /etc/passwd
           Användarkontoinformation.

       /etc/shadow
           Säker användarkontoinformation.

AVSLUTNINGSVÄRDEN

       The pwck command exits with the following values:

       0
           success

       1
           invalid command syntax

       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

SE OCKSÅ

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

shadow-utils 4.17.4                                07-05-2025                                            PWCK(8)