ln:
To create a link with the same content for a file in another location, the commonly used parameter is -s:
ln -s source file object file
Note, don't use ln -s */data/update,
If the source file is a specific file , the target file can be ignored, and it will be automatically linked to the current folder;
Description: -s creates a soft link, the content of the file is not actually copied, the link file does not occupy hard disk space, and the link file is also changed after the source file is changed;