UNIX for Dummies Questions & Answers

hi:

i am trying to understand the concept of the output of ls command, specifically "number of links" for a directory and got utterly confused:

1) when i made first directory in my home directory:

dave@host:~:$ mkdir dir_l1

from the perspective of home directory, the link number for dir_l1show as 2, why 2?

Code:

drwxr-xr-x   2 dave   nobody        512 Apr  4 15:08 dir_l1

2) then i created second directory inside of the first directory:

Code:

dave@host:~:$ mkdir dir_l1/dir_l2

from the perspective of home directory, the link number for dir_l1 shows 3, why 3?

Code:

drwxr-xr-x   3 dave   nobody         512 Apr  4 15:13 dir_l1

from inside of directory dir_l1, the link number for "." is 3, which is the same as its parent directory dir_l1 but ".." also shows 3, why? where did that "total 12" come from?

Code:

dave@host:~:$ ls -al dir_l1/
total 12
drwxr-xr-x  3 dave  nobody  512 Apr  4 15:46 .
drwxr-xr-x  3 dave  nobody  512 Apr  4 15:46 ..
drwxr-xr-x  2 dave  nobody  512 Apr  4 15:46 dir_l2

from the perspective of directory dir_l2, the "." has 2 but ".." has 3, why? where did that 8 coem from?

Code:

dave@host:~:$ ls -al dir_l1/dir_l2/
total 8
drwxr-xr-x  2 dave  nobody  512 Apr  4 15:46 .
drwxr-xr-x  3 dave  nobody  512 Apr  4 15:46 ..

3) then i created third directory

Code:

dave@host:~:$ mkdir dir_l1/dir_l2/dir_l3

from the perspective of home directory, the link number for dir_l1 still is 3, why?

Code:

drwxr-xr-x  3 dave  nobody   512 Apr  4 15:46 dir_l1

from inside of directory dir_l1,

Code:

dave@host:~:$ ls -al dir_l1/
total 12
drwxr-xr-x  3 dave  nobody  512 Apr  4 15:46 .
drwxr-xr-x  3 dave  nobody  512 Apr  4 15:46 ..
drwxr-xr-x  3 dave  nobody  512 Apr  4 16:10 dir_l2

from inside of directory dir_l2:

Code:

dave@host:~:$ ls -al dir_l1/dir_l2/
total 12
drwxr-xr-x  3 dave  nobody  512 Apr  4 16:10 .
drwxr-xr-x  3 dave  nobody  512 Apr  4 15:46 ..
drwxr-xr-x  2 dave  nobody  512 Apr  4 16:10 dir_l3

Every dir has . and .., so there and somwhere the link counts go up. With no children, 2, parent entry and . in myself, and then with every child, 1 more for their .. entry.

Whether it's the root of a partition may also be relevant.