This built-in function ensures that each line in
/etc/group has a valid format (e.g., three items separated by colon and a list of users). If a line is malformed, it is reported and the check fails.
Having a malformed
/etc/group file may break several user-management tools. It may also indicate a break-in or a bug in a custom user-management application. It may also show that someone attempted to add a user with an invalid group name.
/etc/group file to fix the badly formed lines.
description: "This check makes sure /etc/group is valid."