grpck - Unix, Linux Command
NAME
grpck - verify integrity of group files
SYNOPSIS
Tag | Description |
grpck [-r] [group shadow]
|
DESCRIPTION
grpck
verifies the integrity of the system authentication information. All entries in the
/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:
Tag | Description |
o
|
the correct number of fields
|
o
|
a unique group name
|
o
|
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.
OPTIONS
By default,
grpck
operates on the files
/etc/group
and
/etc/gshadow. The user may select alternate files with the
group
and
shadow
parameters. Additionally, the user may execute the command in read-only mode by specifying the
-r
flag. This causes all questions regarding changes to be answered
no
without user intervention.
grpck
can also sort entries in
/etc/group
and
/etc/gshadow
by GID. To run it in sort mode pass it
-s
flag. No checks are performed then, it just sorts.
FILES
Tag | Description |
/etc/group
| |
Group account information.
|
/etc/gshadow
| |
Secure group account information.
|
/etc/passwd
| |
User account information.
|
SEE ALSO
group(5),
passwd(5),
shadow(5),
groupmod(8).
EXIT VALUES
The
grpck
command exits with the following values:
Tag | Description |
0
|
success
|
1
|
invalid command syntax
|
2
|
one or more bad group entries
|
3
|
cant open group files
|
4
|
cant lock group files
|
5
|
cant update group files
|
|