adrian kok adriankok2000@yahoo.com.hk wrote:

...

I have this . folder under tmp <<

It's called a directory, not a "folder" and there's one in every directory. It's a hard link to the current directory, just like ".." is a hard link to the directory above.

...

1/ How they can make it this folder? <<

Create any directory, and it will appear, as I've explained.

...

2/ How can I remove it? <<

If you remove it, you'll be removing the /tmp directory itself, which is not a bright idea. Imagine someone sitting on a branch, sawing away between themselves and the trunk of the tree. . .

Best,

--- Les Bell [http://www.lesbell.com.au] Tel: +61 2 9451 1144