How to delete user group in linux

In Linux, you can use the groupdel command to delete user groups. The function of this command is to delete user groups (groups), that is, the "/etc/gourp" file and the "/etc/gshadow" file. The data information of the target group, the syntax is "groupdel group name".

#The operating environment of this tutorial: linux5.9.8 system, Dell G3 computer.

Linux is a multi-user and multi-tasking operating system. In other words, the Linux system supports multiple users to log in at the same time, and different users can perform different tasks without affecting each other.

A user group is a logical collection of users with the same characteristics. To simply understand, sometimes we need to allow multiple users to have the same permissions, such as permissions to view or modify a certain file. One way is to authorize file access to multiple users separately. If there are 10 users, authorization is required. 10 times, what if there are 100, 1000 or even more users?

Obviously, this method is not reasonable. The best way is to create a group that has permission to view and modify this file, and then put all users who need to access this file into this group. Then, all users have the same permissions as the group, which is the user group.

Grouping users is a means of managing users and controlling access rights in Linux systems. By defining user groups, many programs simplify user management.

How to delete a user group in Linux?

The groupdel command is used to delete user groups (groups). The basic format of this command is:

[root@localhost ~]#groupdel 组名

Using the groupdel command to delete a group actually means deleting the /etc/gourp file and Data information about the target group in the /etc/gshadow file.

For example, for group group1 created with the groupadd command, the execution command is as follows:

[root@localhost ~]#grep "group1" /etc/group /etc/gshadow
/etc/group:group1:x:505:
/etc/gshadow:group1:!::
[root@localhost ~]#groupdel group1
[root@localhost ~]#grep "group1" /etc/group /etc/gshadow
[root@localhost ~]#

Note that the groupdel command cannot be used to delete the group at will. This command only applies to deleting groups that are "not the initial group of any user". In other words, if there is a group that is still the initial group of a user, it cannot be successfully deleted using the groupdel command. For example:

[root@localhost ~]# useradd temp

#Run the following command, you can see that when the temp user is created, the temp group is also created and used as the initial group of the temp user (the group ID is 505)

[root@localhost ~]# grep "temp" /etc/passwd /etc/group /etc/gshadow
/etc/passwd:temp:x:505:505::/home/temp:/bin/bash
/etc/group:temp:x:505:
/etc/gshadow:temp:!::
#下面尝试删除 temp 群组
[root@localhost ~]# groupdel temp
groupdel:cannot remove the primary group of user 'temp'

As you can see, the groupdel command failed to delete the temp group, and the message "cannot delete the initial group of the temp user" was prompted. If you must delete the temp group, you must either modify the temp user's GID, that is, change its initial group to another group, or delete the temp user first.

Remember, although we have learned how to delete group data manually, deleting groups indiscriminately may cause a lot of trouble to other users, so you should be extremely cautious when changing file data.

Related recommendations: "Linux Video Tutorial"

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