grpconv Command in Linux

Description :

The grpconv command creates gshadow from group and an optionally existing gshadow.

Each program acquires the necessary locks before conversion. pwconv and grpconv are similar. First, entries in the shadowed file which don’t exist in the main file are removed. Then, shadowed entries which don’t have ‘x’ as the password in the main file are updated. Any missing shadowed entries are added. Finally, passwords in the main file are replaced with ‘x’. These programs can be used for initial conversion as well to update the shadowed file if the main file is edited by hand.

The following configuration variable in /etc/login.defs changes the behavior of grpconv :

MAX_MEMBERS_PER_GROUP (number)

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.

Usage :

grpconv