What shell command will clone a directory instead of making a deep copy? I wish to take an APFS clone snapshot of a large directory using a shell script. In Finder, I can just Cmd-C, move to the other folder, and Cmd-V and within a few seconds I have a duplicate that takes little extra disk space. Using the cp shell command, it takes ages and creates a copy that takes up disk space. What shell command can duplicate a folder "instantly" the same way Finder can?
The cp command now takes the option -c to create copy on write clones of files.

From the cp man file:

-c    copy files using clonefile(2) 


For example: cp -c my-file my-file-clone