A NIS+ group is a set of NIS+ principals. NIS+ groups are used to assign a set of access rights to NIS+ objects to the members of the group.
This section describes how to use NIS+ group administration commands to perform the following tasks:
The nisgrpadm command performs most group administration tasks, but several other commands affect groups as well:
| Command | Description |
|---|---|
| nissetup | Creates, among other things, the directory in which a domain's groups are stored: groups_dir. |
| nisls | Lists the contents of the groups_dir directory; in other words, all the groups in a domain. |
| nischgrp | Changes or assigns a group to any NIS+ object. |
| nisdefaults | Lists, among other things, the group that will be assigned to any new NIS+ object. |
NIS+ groups can have three types of members: explicit, implicit, and recursive; and three types of nonmembers, also explicit, implicit, and recursive. These member types are used when adding or removing members of a group.
NIS+ groups also accept nonmembers in all three categories: explicit, implicit, and recursive. Nonmembers are principals specifically excluded from a group that they otherwise would be part of.
Nonmembers are identified by a minus sign in front of their name:
Note: The order in which inclusions and exclusions are entered does not matter. Exclusions always take precedence over inclusions. Thus, if a principal is a member of an included implicit domain and also a member of an excluded recursive group, then that principal is not included.
Thus, when using the nisgrpadm command, you can specify group members and nonmembers as shown in the following table:
The niscat -o command can be used to list the object properties and membership of an NIS+ group.
To list the object properties of a group, you must have read access to the groups_dir directory in which the group is stored. Use niscat -o and the group's fully qualified name, which must include its groups_dir subdirectory:
niscat -o group-name.groups_dir.domain-name
For example:
rootmaster# niscat -o sales.groups_dir.wiz.com.
Object Name : sales
Owner : rootmaster.wiz.com.
Group : sales.wiz.com.
Access Rights : ----rmcdr---r---
Time to Live : 1:0:0
Object Type : GROUP
Group Flags :
Group Members : rootmaster.wiz.com.
topadmin.wiz.com.
@.admin.wiz.com.
*.sales.wiz.com.
Several of the group's properties are inherited from the NIS_DEFAULTS environment variable, unless they were overridden when the group was created. The group flags field is currently unused. In the list of group members, the * symbol identifies member domains and the @ symbol identifies member groups.
The nisgrpadm command creates, deletes, and performs miscellaneous administration operations on NIS+ groups. To use nisgrpadm, you must have access rights appropriate for the operation,
| This Operation | Requires This Access Right | To This Object |
|---|---|---|
| Create a group | Create | groups_dir directory |
| Destroy a group | Destroy | groups_dir directory |
| List the Members | Read | the group object |
| Add Members | Modify | the group object |
| Remove Members | Modify | the group object |
The nisgrpadm has two main forms, one for working with groups and one for working with group members.
To create or delete a group, or to lists its members use this form:
nisgrpadm -c group-name.domain-name nisgrpadm -d group-name nisgrpadm -l group-name
To add or remove members, or determine if they belong to the group use this form (where member... can be any combination of the six membership types):
nisgrpadm -a group-name member... nisgrpadm -r group-name member... nisgrpadm -t group-name member...
All operations except create (-c) accept a partially qualified group names. However, even for the -c option, nisgrpadm does not require the use of groups_dir in the group-name argument. In fact, it will not accept it.
To create an NIS+ group, you must have create rights to the groups_dir directory of the group's domain. Use the -c option and a fully qualified group name:
nisgrpadm -c group-name.domain-name
A newly created group contains no members. See Adding Members to an NIS+ Group for information on how to specify who belongs to a group.
The example below creates three groups named admin. The first is in the Wiz.com. domain, the second in sales.wiz.com., and the third in manf.wiz.com. All three are created on the master server of their respective domains.
rootmaster# nisgrpadm -c admin.wiz.com. Group admin.wiz.com. created. salesmaster# nisgrpadm -c admin.sales.wiz.com. Group admin.sales.wiz.com. created. engmaster# nisgrpadm -c admin.manf.wiz.com. Group admin.manf.wiz.com. created.
The group you create will inherit all the object properties specified in the NIS_DEFAULTS variable; that is, its owner, owning group, access rights, and time-to-live. You can view these defaults by using the nisdefaults command (described in Administering NIS+ Access Rights). Used without options, it provides this output:
rootmaster# nisdefaults Principal Name : rootmaster.wiz.com. Domain Name : Wiz.com. Host Name : rootmaster.wiz.com. Group Name : Access Rights : ----rmcdr---r--- Time to live : 12:0:0 Search Path : Wiz.com.
The owner is listed in the Principal Name: field. The owning group is listed only if you have set the NIS_GROUP environment variable.
Of course, you can override any of these defaults at the time you create the group by using the -D option:
salesmaster# nisgrpadm -D group=special.sales.wiz.com.-c admin.sales.wiz.com. Group admin.sales.wiz.com. created.
To delete an NIS+ group, you must have destroy rights to the groups_dir directory in the group's domain. Use the -d option:
nisgrpadm -d group-name
If the default domain is set properly, you do not have to fully-qualify the group name. However, you should check first (use nisdefaults), because you could unintentionally delete a group in another domain. The example below deletes the test.sales.wiz.com. group.
salesmaster% nisgrpadm -d test.sales.wiz.com. Group 'test.sales.wiz.com.' destroyed.
To add members to an NIS+ group you must have modify rights to the group object. Use the -a option:
nisgrpadm -a group-name members. . .
As described in Specifying Group Members, you can add principals (explicit members), domains (implicit members), and groups (recursive members). You do not have to fully qualify the name of the group or the name of the members who belong to the default domain. This example adds the NIS+ principals panza and valjean, both from the default domain, sales.wiz.com., and the principal makeba, from the manf.wiz.com. domain, to the group Ateam.sales.wizCom.
client% nisgrpadm -a Ateam panza valjean makeba.manf.wiz.com. Added panza.sales.wiz.com to group Ateam.sales.wiz.com Added valjean.sales.wiz.com to group Ateam.sales.wiz.com Added makeba.manf.wiz.com to group Ateam.sales.wiz.com
To verify the operation, use the nisgrpadm -l option. Look for the members under the Explicit members heading.
This example adds all the NIS+ principals in the Wiz.com. domain to the Staff.wiz.com. group. It is entered from a client in the wiz.com. domain. Note the * symbol and the dot in front of the domain name.
client% nisgrpadm -a Staff *.wiz.com. Added *.wiz.com. to group Staff.manf.wiz.com.
This example adds the NIS+ group admin.wiz.com. to the admin.manf.wiz.com. group. It is entered from a client of the manf.wiz.com. domain. Note the @ symbol in front of the group name.
client% nisgrpadm -a admin @admin.wiz.com. Added @admin.wiz.com. to group admin.manf.wiz.com.
To list the members of an NIS+ group, you must have read rights to the group object. Use the -l option:
nisgrpadm -l group-name
This example lists the members of the admin.manf.wiz.com. group. It is entered from a client in the manf.wiz.com. group:
client% nisgrpadm -l admin
Group entry for admin.manf.wiz.com. group:
No explicit members
No implicit members:
Recursive members: @admin.wiz.com.
No explicit nonmembers
No implicit nonmembers
No recursive nonmembers
To remove members from an NIS+ group, you must have modify rights to the group object. Use the -r option:
nisgrpadm -r group-name members. . .
This example removes the NIS+ principals allende and hugo.manf.wiz.com. from the Ateam.sales.wiz.com group. It is entered from a client in the sales.wiz.com. domain:
client% nisgrpadm -r Ateam allende hugo.manf.wiz.com. Removed allende.sales.wiz.com. from group Ateam.sales.wiz.com. Removed hugo.manf.wiz.com. from group Ateam.sales.wiz.com.
This example removes the admin.wiz.com. group from the admin.manf.wiz.com. group. It is entered from a client in the manf.wiz.com. domain:
client% nisgrpadm -r admin @admin.wiz.com. Removed @admin.wiz.com. from group admin.manf.wiz.com.
To find out whether an NIS+ principal is a member of a particular NIS+ group you must have read access to the group object. Use the -t option:
nisgrpadm -t group-name members. . .
This example tests whether the NIS+ principal topadmin belongs to the admin.wiz.com. group. It is entered from a client in the Wiz.com. domain.
client% nisgrpadm -t admin topadmin topadmin.wiz.com. is a member of group admin.wiz.com.
This example tests whether the NIS+ principal jo, from the sales.wiz.com. domain, belongs to the admin.sales.wiz.com. group. It is entered from a client in the wiz.com. domain.
client% nisgrpadm -t admin.sales.wiz.com. jo.sales.wiz.com. jo.sales.wiz.com. is a member of group admin.sales.wiz.com.