Today we'll work in Mac OS Terminal.
You can try the Linux option later within a web-based terminal
directory “above” containing the “current” directory.
drwx------+ 5 YOU AD\Domain Users 170 Mar 15 18:36 Desktop
drwx------+ 3 YOU AD\Domain Users 102 Jun 19 2014 Documents
drwx------+ 5 YOU AD\Domain Users 170 Mar 15 18:36 Downloads
[email protected] 43 YOU AD\Domain Users 1462 Mar 15 18:36 Library
drwx------+ 3 YOU AD\Domain Users 102 Jun 19 2014 Movies
drwx------+ 3 YOU AD\Domain Users 102 Jun 19 2014 Music
drwx------+ 3 YOU AD\Domain Users 102 Jun 19 2014 Pictures
drwxr-xr-x+ 5 YOU AD\Domain Users 170 Jun 19 2014 Public
In order to organize privileges and permissions the Unix system is designed around the following definitions:
|user||A user of the computer. Your specific user name is shown with
|group||Multiple users can be assembled into a group e.g. from the same lab. The system administrator of the computer will create the group.|
|others||This is "anyone" else; on older system this was called "the world".|
|all||Contains everyone including user, group and anyone but not present in this listing.|
Table: Definitions of user groups. In the listing above they belong to user
YOU and group
|d||This is a directory|
|r||The file can be read.|
|w||The file can be writen or even overwriten.|
|x||The execute privilege. For a directory it means its content can be listed.|
|-||The privilege within that column is not granted.|
Table: Privilege tags
Table: Understanding I/O streams numbers
The glass content can vary. The glass is the variable, the content is the variable value.
Separating the container and the content:
‘glass’ is the container ‘$glass’ is the content and can vary.