'cp -a' source specification for hidden files

Question

Copying hidden files with Linux, I realized I should use :

cp -a /mnt/sda8/john/. /mnt/sdb2/john

instead of :

cp -a /mnt/sda8/john/ /mnt/sdb2/john

What's the point in adding a . after the source directory ? What does it mean exactly ? To me, the second version should work as well since no globbing is involved.

Answer 1

a simpler and more common way of doing this would be:

cp -a /mnt/sda8/john /mnt/sdb2/

. means the current directory, and /mnt/sda8/john is equivalent to /mnt/sda8/john/.

however, adding a trailing / such as you have done may throw some programs in some distributions off and thus fail to do what you want.