Provided by: passwd_220.127.116.11-1ubuntu2_i386
grpck - verify integrity of group files
grpck [-r] [group [ shadow ]]
grpck [-s] [group [ shadow ]]
The grpck command verifies the integrity of the system authentication
information. All entries in /etc/group and /etc/gshadow are checked to
see that the entry has the proper format and valid data in each field.
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 group name
· a valid list of members and administrators
The checks for correct number of fields and unique group 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 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/group file are not able to alter
corrupted or duplicated entries. grpck should be used in those
circumstances to remove the offending entry.
The options which apply to the grpck command are:
Execute the grpck command in read-only mode. This causes all
questions regarding changes to be answered no without user
Sort entries in /etc/group and /etc/gshadow by GID.
By default, grpck operates on /etc/groupand /etc/gshadow. The user may
select alternate files with the group and shadow parameters.
The following configuration variables in /etc/login.defs change the
behavior of this tool:
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.
Group account information.
Secure group account information.
User account information.
group(5), groupmod(8), gshadow(5) passwd(5), pwck(8), shadow(5).
The grpck command exits with the following values:
invalid command syntax
one or more bad group entries
can´t open group files
can´t lock group files
can´t update group files