To write scripts in linux, you must grant the tutorial permission.

To write a script in linux, you must grant the tutorial permission-Linux general technology-Linux programming and kernel information. For details, refer to the following section. Command name: chmod
Permission: All Users
Usage: chmod [-cfvR] [-- help] [-- version] mode file...
Note: The file calling permissions for Linux/Unix are divided into three levels: file owner, group, and others. Chmod can be used to control how files are called by others.
Parameters:
Mode: permission setting string in the following format: [ugoa...] [[+-=] [rwxX]...] [,...], where
U indicates the owner of the file, g indicates that the owner of the file belongs to the same group, o indicates that the owner of the file belongs to other people, and a indicates that all three are.
+ Adds a permission,-Indicates canceling the permission, and = indicates a unique permission.
R indicates that the file can be read, w indicates that the file can be written, and x indicates that the file can be executed only when the file is a subdirectory or the file has been set to executable.
-C: if the permission of the file has been changed, the change action is displayed.
-F: Do not display an error message if the file permission cannot be changed.
-V: displays details of permission changes.
-R: Change the permissions of all files and sub-directories in the current directory in the same way (that is, change one by one in the way of delivery)
-- Help: displays auxiliary instructions
-- Version: displays the version.

Example: Set the file file1.txt to readable by all users: chmod ugo + r file1.txt

Set the file file1.txt to be readable by everyone: chmod a + r file1.txt

Set file1.txt and file2.txt as the owner of the archive, which can be written to the same group to which the archive belongs, but cannot be written to other persons: chmod ug + w, o-w file1.txt file2.txt

Set ex1.py to run: chmod u + x ex1.py

Set all files and subdirectories in the current directory to anyone to read: chmod-R a + r *

In addition, chmod can use numbers to indicate permissions, such as chmod 777 file.
Syntax: chmod abc file
Each a, B, and c is a number, indicating the permissions of the User, Group, and Other respectively.
R = 4, w = 2, x = 1
If you want the rwx attribute, 4 + 2 + 1 = 7;
If the rw-attribute is required, 4 + 2 = 6;
If you want the r-x attribute, 4 + 1 = 7.

Example:
Chmod a = rwx file and chmod 777 file have the same effect
Chmod ug = rwx, o = x file, and chmod 771 file have the same effect.
If chmod 4755 filename is used, the program can have root permissions.