Ownerships and permissions in a UNIX directory listing as a protection matrix

 

 

To represent the ownerships and permissions in a UNIX directory listing as a protection matrix, we need to first identify the users, groups, and files involved. The provided permissions indicate the rights for each user and group for each file.

Users and Groups

– Users: – gmw
– asw

– Groups:- users (gmw, asw)
– devel (asw)

Files

1. PPP Notes
2. prog1
3. project.t
4. splash.gif

Permissions Breakdown

Let’s break down the permissions for each file:

1. PPP Notes: rw-r–r–

– Owner (gmw): read and write (rw-)
– Group (users): read (r–)
– Others: read (r–)

2. prog1: rwxr-xr-x

– Owner (asw): read, write, and execute (rwx)
– Group (devel): read and execute (r-x)
– Others: read and execute (r-x)

3. project.t: rwrw-r—–

– Owner (asw): read and write (rw-)
– Group (users): read and write (rw-)
– Others: no permissions (—)

4. splash.gif: rwr–r—–

– Owner (asw): read and write (rw-)
– Group (devel): read (r–)
– Others: no permissions (—)

Protection Matrix Representation

Now we can create a protection matrix based on the information gathered. The rows will represent the domains (individual users and groups), while the columns will represent the files. Permissions can be represented as follows:

– r = Read
– w = Write
– x = Execute
– – = No permission

The protection matrix is structured as follows:

Domain PPP Notes prog1 project.t splash.gif
gmw rw- — — —
asw — rwx rw- rw-
users r– r-x rw- —
devel — r-x — r–

Explanation of the Matrix:

– Row for gmw: Has read and write permissions for “PPP Notes” but no access to other files.
– Row for asw: Has full permissions for “prog1,” read and write for “project.t,” and read and write for “splash.gif.”
– Row for users group: Members have read access for “PPP Notes,” read and execute access for “prog1,” and read and write access for “project.t.”
– Row for devel group: Members have read access for “prog1” and “splash.gif” but no access to other files.

This protection matrix summarizes the permissions associated with each user, group, and file in the UNIX directory listing provided.