Verifies the correctness of a group definition. This document describes both the AIX® grpck command and the System V grpck command.
The grpck command verifies the correctness of the group definitions in the user database files by checking the definitions for ALL the groups or for the groups specified by the Group parameter. If more than one group is specified, there must be a space between the groups.
You must select a flag to indicate whether the system should try to fix erroneous attributes. The following attributes are checked:
Item | Description |
---|---|
name | Checks the uniqueness and composition of the group name. The group name must be a unique string of eight bytes or less. It cannot begin with a + (plus sign), a : (colon), a - (minus sign), or a ~ (tilde). It cannot contain a colon (:) in the string and cannot be the ALL or default keywords. No system fix is possible. |
groupID | Checks the uniqueness and composition of the group ID. The ID must not be null and must consist of decimal digits only. No system fix is possible. |
users | Checks the existence of the users listed in the group database files. If you indicate that the system should fix errors, it will delete all the users that are not found in the user database files. |
adms | Checks the existence of the users listed as group administrators in the group database files. If you indicate that the system should fix errors, it will delete all the administrators that are not found in the user database files. |
Item | Description |
---|---|
admin | Checks for a valid admin attribute for each group in the /etc/security/group file. No system fix is available. |
Generally, the sysck command calls the grpck command as part of the verification of a trusted-system installation. In addition, the root user or a member of the security group can enter the command.
The grpck command checks to see if the database management security files (/etc/passwd.nm.idx, /etc/passwd.id.idx, /etc/security/passwd.idx, and /etc/security/lastlog.idx) files are up-to-date or newer than the corresponding system security files. Please note, it is alright for the /etc/security/lastlog.idx to be not newer than /etc/security/lastlog. If the database management security files are out-of-date, a warning message appears indicating that the root user should run the mkpasswd command.
Item | Description |
---|---|
-n | Reports errors but does not fix them. |
-p | Fixes errors but does not report them. |
-t | Reports errors and asks if they should be fixed. |
-y | Fixes errors and reports them. |
Access Control: This command should grant execute (x) access to the root user and members of the security group. The command should be setuid to the root user and have the trusted computing base attribute.
Files Accessed:
Mode | File |
---|---|
r | /etc/passwd |
r | /etc/security/user |
rw | /etc/security/group |
rw | /etc/group |
Auditing Events:
Event | Information |
---|---|
GROUP_User | user, groups, attribute | error, status |
GROUP_Adms | user, groups, attribute | error, status |
grpck -n ALL
grpck -p ALL
grpck -n install
ORgrpck -t install
ORgrpck -y install
The grpck command does not correct the group names and IDs. Therefore, the -n, -t and -y flags report problems with group names and group IDs, but do not correct them.Item | Description |
---|---|
/usr/sbin/grpck | Contains the grpck command. |
/etc/passwd | Contains the basic attributes of users. |
/etc/security/user | Contains the extended attributes of users. |
/etc/group | Contains the basic attributes of groups. |
/etc/security/group | Contains the extended attributes of groups. |
/usr/sysv/bin/grpck
The /usr/sysv/bin/grpck command verifies the correctness of the group definitions in the user database files by checking the definitions for ALL the groups.This /usr/sysv/bin/grpck command is a System V version of the existing grpck command in /usr/sbin/.This command calls the /usr/sbin/grpck command with -n and ALL options.
/usr/sysv/bin/grpck