Odd that you mention File::Copy. As a sysadmin, I care about file permissions. 'cp' cares about them too. Hey, even POSIX cares about them enough to specify how 'cp' should behave with respect to file permissions.

File::Copy doesn't care about file permissions - the permissions it creates for a newly created file are independent of the original file. Hate! A copied executable should be executable, but File::Copy disagrees.

Therefore, I always use system 'cp', $source, $destination. Not to mention that system 'cp', @sources, $destination just works.