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GRPCK(8)                                      System Management Commands                                     GRPCK(8)



NAME
       grpck - verify integrity of group files

SYNOPSIS
       grpck [options] [group [ shadow ]]

DESCRIPTION
       The grpck command verifies the integrity of the groups information. It checks that all entries in
       /etc/groupand /etc/gshadow 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 group name

       ·   a valid group identifier (/etc/group only)

       ·   a valid list of members and administrators

       ·   a corresponding entry in the /etc/gshadow file (respectively /etc/group for the gshadow checks)

       The checks for correct number of fields and unique group name are fatal. If an 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 group 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 groupmod
       command to correct the error.

       The commands which operate on the /etc/groupand /etc/gshadow files are not able to alter corrupted or
       duplicated entries.  grpck should be used in those circumstances to remove the offending entries.

OPTIONS
       The -r and -s options cannot be combined.

       The options which apply to the grpck command are:

       -h, --help
           Display help message and exit.

       -r, --read-only
           Execute the grpck command in read-only mode. This causes all questions regarding changes to be answered no
           without user intervention.

       -R, --root CHROOT_DIR
           Apply changes in the CHROOT_DIR directory and use the configuration files from the CHROOT_DIR directory.

       -s, --sort
           Sort entries in /etc/groupand /etc/gshadow by GID.

       By default, grpck operates on /etc/groupand /etc/gshadow. The user may select alternate files with the
       groupand shadow parameters.

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


           this variable unless you really need it.

FILES
       /etc/group
           Group account information.

       /etc/gshadow
           Secure group account information.

       /etc/passwd
           User account information.

EXIT VALUES
       The grpck command exits with the following values:

       0
           success

       1
           invalid command syntax

       2
           one or more bad group entries

       3
           can't open group files

       4
           can't lock group files

       5
           can't update group files

SEE ALSO
       group(5), groupmod(8), gshadow(5),passwd(5), pwck(8), shadow(5).



shadow-utils 4.1.5.1                                  11/05/2016                                             GRPCK(8)