Applying Linux ACLs: Personalized File Permission Management

"Linux ACL Application Example: Customized File Access Permissions"

In the Linux system, ACL (Access Control List) is a more flexible and refined File access control allows administrators to set different permissions for each file. Through ACL, we can achieve more detailed management of files and achieve customized file access permissions. This article will introduce how to use ACL in Linux systems, and give some specific application examples and code examples.

1. What is ACL

ACL refers to Access Control List, that is, access control list. It is a file system permission control mechanism that allows users to have more precise control when accessing files and directories. ACL can set the permissions of multiple users or user groups for each file and directory, thereby achieving more flexible file permission management.

2. Set ACL

In Linux systems, to use the ACL function, you first need to ensure that the file system supports ACL. Most modern Linux distributions support ACL, and the ACL function can be enabled through the acl option when the file system is mounted.

To set ACL permissions for a file or directory, you can use the setfacl command. The basic syntax is as follows:

setfacl -m u:username:permissions filename

Among them, u:username means setting ACL permissions for the specified user, permissions means the specific settings of permissions, filenameIndicates the file or directory for which ACL permissions are set.

3. Application example: Use ACL to control file access permissions

Example 1: Set read and write permissions for specific users

Suppose we have a fileexample.txt , now to set read and write permissions for user user1, we can use the following command:

setfacl -m u:user1:rw example.txt

In this way, user user1 can access example .txt file for reading and writing operations.

Example 2: Set specific permissions for a specific user group

Suppose we have a directory example_dir, and now we need to set read and write for the user group group1 For execution permission, we can use the following command:

setfacl -m g:group1:rwx example_dir

In this way, members of the group1 user group can read, write, and execute operations on the example_dir directory.

Example 3: Set default ACL permissions

Sometimes we want to set default ACL permissions for a directory to ensure that newly created files follow the same permissions rules. You can use the following command to set the default ACL permissions:

setfacl -d -m u::rwx,g::r-x,o::r-x /path/to/directory

Conclusion

Through ACL, we can more flexibly control the access permissions of files and directories, and in actual applications, we can customize access according to needs. permissions to improve the security and accuracy of file management. We hope that the ACL application examples and code samples introduced in this article can help readers better understand and apply ACL functions.

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