Linux permission Concept

In linux, each user must belong to a group and cannot be independent from the group. In linux, each file has the concept of owner, group, and other groups. In linux, how does one add groupadd group name www.2cto.com to view information about all groups in linux vi/etc/group or cat/etc/group to create users, you can also specify the useradd-g group name to which the user is assigned. You can view all user information in linux. The permission for vi/etc/passwd cat/etc/passwd is divided into three types: r can be expressed in 4, w can be written in 2, x executable uses 1 to represent-rw-r--- all files of the file type www.2cto.com rw-all permissions on the file r-the group in which the file is located permission r--How do users in other groups modify the object access permission for the object's permissions? When you add a user to a chmod 777 file or folder, you can specify the group to which the user is added, similarly, with the root management permission, you can change the usermod-g group name username of a user's group. You can use usermod-d directory name username // to change the initial directory that the user logs on. you can use [chown user name file name] to repair the owner of the file. You can also use [chgrp group name file name] to modify the group in which the file is located.