exch

exch file1 file2

exch swaps the filepaths and filenames of two files. After the operation, file1 will have the contents that were at file2's path and vice versa.
Useful for quickly swapping configuration files or backups.

file1

First file to swap

Second file to swap

Both files must exist. Atomic operation using rename(). Files must be on the same filesystem.

mv(1), cp(1)