Chmod calculator

Chmod calculator Introduction

1. In Unix-like operating systems, the chmod (change mode) command is used to change the access permission of files or directories.

2, permissions are divided into three groups of user types, each group of user types have three kinds of permissions.

(1), User: indicates the owner of the file.

(2), Group: indicates the user group to which the file owner belongs.

(3), Others: other users who are neither the owner of the file nor the user group to which the file belongs.

3. Each permission type has the following three types.

(1), Read (Read) : denoted by the letter r, allowing the file content to be read.

(2), Write (Write) : represented by the letter w, allowing modification of the file content.

(3), Execute (Execute) : with the letter x, for the file, indicates that the execution of the file is allowed; For directories, it means that the directory is allowed to be traversed (that is, entered).

4, permissions can be expressed in octal, can also be expressed in symbols.

(1), octal notation uses three digits, each digit represents a group of user permissions;

(2), symbolic notation uses characters to represent permissions;