Write a screen lock script

For more information about how to write a screen lock script-general Linux technology-Linux technology and application, see the following. The questions mentioned earlier are not correct ..
You can directly use commands to achieve the effect. There is no need to write a script.

Enter EXIT on the command line and enter the user name and password again.
But was the running program also interrupted?
If you want to write a script to achieve the screen lock effect without interrupting the running program
Enter password to restore
Can this script be written?
How to write?
I don't know if I can provide an example ..

I am a beginner and may not understand LINUX.
If something is wrong, I hope I can correct it.