The “ditto” command has a --nocache option that thrills me.

The “ditto” command copies files, directories, etc. in an “Apple safe” way. It copies the resource forks and even generates the “._filename” files if copying to a file system that do not natively support resource forks. According to the man page:

--nocache

do not perform copies using the Mac OS X Unified Buffer Cache. Files read and written will not be cached, although if the file is already present in the cache, the cached information will be used.

That is... if you do a backup using “ditto --nocache” this operation won’t pollute your disk cache.

( Cut for space... a longer description useful to geeks and geek-wannabes )