What happens if the destination directory doesn't exist?

That's an excellent follow-up question about the mv command!

If you try to move a file to a destination directory that does not exist, the mv command will give you an error message. It cannot create the directory for you.

For example, if you tried to run:

mv file.txt non_existent_directory/

and non_existent_directory doesn't exist, you would typically see an error like:

mv: cannot stat 'non_existent_directory/': No such file or directory

Or, more commonly, if non_existent_directory doesn't exist, mv might interpret non_existent_directory/ as a new filename in the current directory, resulting in file.txt being renamed to non_existent_directory/ (which is usually not what you want, and could lead to strange file names if the / character is allowed by your file system).

The key takeaway is: When moving to a directory, the destination directory must already exist. If it doesn't, you should create it first using mkdir before attempting to move files into it.

You can observe a similar error in your user_history:

mv: cannot stat 'testdir_copy': No such file or directory

In this case, you tried to rename testdir_copy to new_testdir, but testdir_copy didn't exist to begin with. The same principle applies if the destination is a directory that doesn't exist.

Does that clarify what happens in such a scenario? Keep up the great questions!