Move a file to a directory that is within another directory and rename it in one command line?

Question

So, we have a parent_dir and it contains a child_dir and a file1. How can I move a file1 to a child_dir and rename it as file2? let's assume my pwd is /var

Answer 1

You can just move a file from one dest. to another (it changes its name):

mv /parent_dir/file1 /parent_dir/child_dir/file2