Does cp -a refresh existing files, overwrite or skip

Question

If I use cp in archive mode e.g

cp -a /my_old_directory/* /new_location/my_new_directory/

to replicate a directory structure and all that is in it.

If I then run the same command again will any changed files be refreshed or over-written or skipped?

(I know rsync is more advanced at this kind of thing, I'm just curious about cp -a as I can't find any description of what it actually does in this case.

Answer 1

cp will overwrite all files.

what you are looking for if you do not want that behavior is the rsync command.

the -a option just means it will preserve the source file metadata, like creation time, owner, access mode and such..

Answer 2

Existing files will be over-written, as somewhat implied in gilles' answer to Difference between cp -r and cp -a.