To practice/review some previously learned skills in order to obtain better mastery.

Since we have our President's Day mini break next week, we will not actually have the sit-down portion of the class.

Instead of giving you some amazing new mind-blowing project to redefine your very life as we know it, I figured I'd instead give you a chance to take a quick breather and get in some review prior to resuming in full force.

For this week, the main topic of review will be file permissions. We see them when running an ls -l, for example:

lab46:/usr/local/bin$ ls -l submit tclbiff
-rwxr-xr-x  1 root   staff    115 Oct 14  2010 sshfix
-rwxr-x---  1 wedge  lab46   4651 Jan 27 05:58 submit
lab46:/usr/local/bin$ 

Of course, the file permission part is:

    -rwxr-xr-x

We split this into 3 fields (the leftmost field is for file type) into user, group, and other.

Breakdown is as follows:

• read ® is 4
• write (w) is 2
• execute/search (x) is 1
• nothing (-) is 0

In any given field, we add up the values, which will result in a value within the range 0-7.

So, in our example above, broken down showing the component permissions:

               u      g      o
          -   rwx    r-x    r-x
               7      5      5

I wrote a tool for you to use in this project called urev.

Your task will be to run this and successfully complete 96