Commands Reference, Volume 1

chgrpmem Command

Purpose

Changes the administrators or members of a group.

Syntax

chgrpmem [ { { -a | -m } { + | - | = } User ... } ] Group

Description

The chgrpmem command changes the administrators or members of the group specified by the Group parameter. Use this command to add, delete, or set a group's members or administrators list. You cannot remove users from their primary group. A user's primary group is maintained in the /etc/passwd file. If you specify only a group with the chgrpmem command, the command lists the group's members and administrators.

To add, delete, or set a user as a group administrator, specify the -a flag. Otherwise, to add, delete, or set a user as a group member, specify the -m flag. You must specify one of these flags and an operator to change a user's group membership. The operators do the following:

+	Adds the specified user.
-	Deletes the specified user.
=	Sets the list of administrators or members to the specified user.

You can specify more than one User parameter at a time. To do this, specify a comma-separated list of user names.

See the chgroup command for a list of restrictions that apply to changing group information.

Flags

-a	Changes a group's administrators list.
-m	Changes the group's members list.

Security

Access Control: All users should have execute (x) access to this command since the command itself enforces the access rights. This command should be installed as a program in the trusted computing base (TCB). The command should be owned by the security group with the setgid (SGID) bit set.

Files Accessed:

Mode	File
x	/usr/bin/chgroup
r	/etc/passwd
r	/etc/group
rw	/etc/security/group

Examples

To remove jones as an administrator of the f612 group, enter:
chgrpmem -a - jones f612
To add members davis and edwards to group f612, enter:
chgrpmem -m + davis,edwards f612
To list members and administrators of group staff, enter:
```
chgrpmem staff
```

Files

/usr/bin/chgrpmem	Specifies the path to the chgrpmem command.
/etc/passwd	Contains the basic attributes of users.
/etc/group	Contains the basic attributes of groups.
/etc/security/group	Contains the extended attributes of groups.

Related Information

The chfn command, chgroup command, chsh command, chuser command, lsgroup command, lsuser command, mkgroup command, mkuser command, passwd command, pwdadm command, rmgroup command, rmuser command, setgroups command, setsenv command.

For more information about the identification and authentication of users, discretionary access control, the trusted computing base, and auditing, refer to Security Administration in AIX 5L Version 5.2 System Management Concepts: Operating System and Devices.