A permission is a number and a string, and the whole skill is moving between the two. These questions check that you can read the fourth digit, tell a capital letter from a lowercase one, and write a mode with the symbolic form.
Each one is marked as you go, and the explanation arrives straight after, which is
the part worth reading.
4 questions, marked as you go.
Tasks
These need your own device. Run the command in Termux, then paste what it printed.
The marking looks at what the output means, so spacing, version numbers and
ordering do not matter. If you have not installed anything yet, the
lesson covers the setup.
Read a mode with a special bit
The permtool.sh you finished is saved next to you. This hands it 4755, the mode of a setuid program, and asks for both notations plus a description. Paste the whole output.
Run this in Termux
On your own device. Nothing on this page executes it. The command runs in
your terminal, and this box only reads what you paste back.
bash permtool.sh 4755
The first line is the symbolic form, and there is a lowercase letter where you might expect an x.
the symbolic form carries the setuid bit
the special bit was explained rather than just converted
the classes were described in words
the script ran
What a good answer looks like
The symbolic form rwsr-xr-x on the first line, then a description of what each class allows, then a line saying setuid is on. The 4 in front of the 755 is the special digit, and it lands in the owner's execute position as a lowercase s. Lowercase means the special bit is on and execute is on as well. If you run it on 4644 instead, the same position becomes a capital S, and the script says so: setuid is on but owner execute is off, so the program does nothing.
Marking your own work
Both halves of this are checked in your browser, with no server involved, so nothing
stops you from pasting output you did not run. The tasks are written so that the
easiest way to pass one is to actually do it and read the result, which is the whole
intention.