background
In the Linux system, you can define the permissions of any user, group and other. Implementing ACL based on common files or directories is actually setting file or directory operation permissions for specified users or user groups. In ordinary permissions, users have only three identities for files, namely, owner, group, and others; each user identity has three permissions: read, write, and execute.
After an ACL is set for a directory, the files in the directory will inherit its ACL; and if an ACL is set for a file, the file will not inherit the ACL of the directory where it is located, and its file level is higher than the directory level.
As shown in the figure above, the three permission configurations of ordinary users are often not satisfied in some scenarios. For example, st users are restricted to only rx permissions, while the owner and group have rwx permissions, and the permissions of other are 0, that is, no How to configure permissions? At this time, by using ACL to grant rx permissions for the /project directory to the user st, the scenario can be satisfied by st not being the owner of the /project directory or the group.
Scene reference:
假设某单位项目中创建了一个项目文件夹，管理员和开发团队Rocket对该目录均具备 rwx 的权限，因为在该文件夹下