Unix Assignment and a
Script-Based Grading Assistant
In section 1, is an example of a homework assignment which I emailed
to my students in the Introduction to Unix class in Spring 1999.
Basically, students were asked to create a certain directory structure
and certain files within it. They had to set up the files with certain
permissions as well. My problem with grading this
type of assignment is that I am locked out of the student accounts
so I cannot see that they have done it correctly unless I am right
there when they are logged onto the system. This is because I encourage all
my students to set the security settings for their accounts to keep others
from copying their work (but that locks me out as well).
The solution was to take advantage of something else I did
early in the semester, when I had the students set up their accounts so
that they could automatically run commands (or a command SCRIPT) that I
created in a particular directory which I controlled. I created a
script called s99_lab3 and told students to run that script as
the last step of the assignment. Why is this the solution?
Because the student is sending the results to me rather than me trying to
get them on my own. Thus, the student's own "permission settings" apply
(and usually one has permission to look at their own work).
In section 2, I show the actual command script which I created
for this purpose.
It is not important to understand the details. Basically, it
generates output summarizing what the student created (including the
dates when different items were generated... important for
verifying that electronic cheating is unlikely) and then emails that
to me. I even allow the student to review the output first and decide
if they really want to send it. If any errors are made then it should
be obvious so that they can fix it and retry.
In section 3, I show an example of what I get by email from the
student. In this case I ran a hypothetical example in which the
student did not do everything correctly. I changed all instances
of the username to johndoe for this illustration.
1. The Assignment
<![CDATA[
Spring 1999 Intro to Unix
Lab 3 (10 points)
On page 84 of the textbook you will see a file structure that I want you
to create. First, however, I want you to create a directory called
chap7ex (spelled EXACTLY as shown). Thus the structure will be as follows:
[your home directory]
|
|
chap7ex
/|\ \
/ | \ \___
/ | \ \___
/ | \ \
Cal fun jul99 summer99
/ \
/ \
1999 Months
/ \
/ \
june99 aug99
The 1999 file should contain the entire 1999 calendar. The summer99 file
should contain the calendars for June, July, and August of 1999 (one after
the other). The fun file should contain the word "fun" in banner size.
The others contain individual month calendars as the name suggests. For
all of this you will use the cal and banner commands.
Set the permissions on all of these (using chmod) as follows:
rwxr--r-- chap7ex
rwxr-xr-x Cal
rwxr----- fun
rw-r--r-- jul99
rw-r--r-- summer99
rw------- 1999
rwxr-x--- Months
r--r--r-- june99
r--r--r-- aug99
Finally, you are to type the following command when you are done which
sends it all to me.
s99_lab3
]]>
2. The Script
<![CDATA[
echo Do you want to see what you will be sending first? \(n or y\)
read answer
if [ $answer = "y" ]
then
cd
(
echo "User: $LOGNAME"; echo "Date: `date`"; echo; echo
echo -n "=======================================";
echo "=======================================";
ls -lR chap7ex;
echo -n "================================== fun ";
echo "=======================================";
cat chap7ex/fun;
echo -n "================================ jul99 ";
echo "=======================================";
cat chap7ex/jul99;
echo -n "============================= summer99 ";
echo "=======================================";
cat chap7ex/summer99;
echo -n "================================= 1999 ";
echo "=======================================";
cat chap7ex/Cal/1999;
echo -n "=============================== june99 ";
echo "=======================================";
cat chap7ex/Cal/Months/june99;
echo -n "================================ aug99 ";
echo "=======================================";
cat chap7ex/Cal/Months/aug99;
echo -n "=======================================";
echo "=======================================";
) 2>&1 | more
echo; echo; echo Do you now want to send all this to jsjones? \(n or y\)
read answer
if [ $answer = "y" ]
then
echo Okay, it is being sent to jsjones as requested...
else
echo Okay, it is NOT being sent.
exit
fi
fi
cd
(
echo "User: $LOGNAME"; echo "Date: `date`"; echo; echo
echo -n "=======================================";
echo "=======================================";
ls -lR chap7ex;
echo -n "================================== fun ";
echo "=======================================";
cat chap7ex/fun;
echo -n "================================ jul99 ";
echo "=======================================";
cat chap7ex/jul99;
echo -n "============================= summer99 ";
echo "=======================================";
cat chap7ex/summer99;
echo -n "================================= 1999 ";
echo "=======================================";
cat chap7ex/Cal/1999;
echo -n "=============================== june99 ";
echo "=======================================";
cat chap7ex/Cal/Months/june99;
echo -n "================================ aug99 ";
echo "=======================================";
cat chap7ex/Cal/Months/aug99;
echo -n "=======================================";
echo "=======================================";
) | mailx -s s99_lab3 jsjones
]]>
3. The Returned Result (example)
<![CDATA[
Date: Mon, 8 Mar 1999 13:07:06 -0600 (CST)
From: johndoe
To: jsjones
Subject: s99_lab3
Mime-Version: 1.0
User: johndoe
Date: Mon Mar 8 13:07:05 CST 1999
==============================================================================
total 6
drwxr-xr-x 3 johndoe users 1024 Feb 12 10:57 Cal
-rw-r--r-- 1 johndoe users 153 Feb 12 09:50 fun
-rw-r--r-- 1 johndoe users 401 Feb 12 10:56 summer99
chap7ex/Cal:
total 6
-rw-r--r-- 1 johndoe users 1729 Feb 12 10:57 1999
drwxr-xr-x 2 johndoe users 1024 Mar 8 11:49 Months
chap7ex/Cal/Months:
total 4
-rw-r--r-- 1 johndoe users 1 Mar 8 11:49 June1999
---------- 1 johndoe users 1 Mar 8 11:49 aug99
================================== fun =======================================
#######
# # # # #
# # # ## #
##### # # # # #
# # # # # #
# # # # ##
# #### # #
================================ jul99 =======================================
cat: Cannot open chap7ex/jul99: No such file or directory
============================= summer99 =======================================
June 1999
S M Tu W Th F S
1 2 3 4 5
6 7 8 9 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28 29 30
July 1999
S M Tu W Th F S
1 2 3
4 5 6 7 8 9 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28 29 30 31
August 1999
S M Tu W Th F S
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31
================================= 1999 =======================================
1999
Jan Feb Mar
S M Tu W Th F S S M Tu W Th F S S M Tu W Th F S
1 2 1 2 3 4 5 6 1 2 3 4 5 6
3 4 5 6 7 8 9 7 8 9 10 11 12 13 7 8 9 10 11 12 13
10 11 12 13 14 15 16 14 15 16 17 18 19 20 14 15 16 17 18 19 20
17 18 19 20 21 22 23 21 22 23 24 25 26 27 21 22 23 24 25 26 27
24 25 26 27 28 29 30 28 28 29 30 31
31
Apr May Jun
S M Tu W Th F S S M Tu W Th F S S M Tu W Th F S
1 2 3 1 1 2 3 4 5
4 5 6 7 8 9 10 2 3 4 5 6 7 8 6 7 8 9 10 11 12
11 12 13 14 15 16 17 9 10 11 12 13 14 15 13 14 15 16 17 18 19
18 19 20 21 22 23 24 16 17 18 19 20 21 22 20 21 22 23 24 25 26
25 26 27 28 29 30 23 24 25 26 27 28 29 27 28 29 30
30 31
Jul Aug Sep
S M Tu W Th F S S M Tu W Th F S S M Tu W Th F S
1 2 3 1 2 3 4 5 6 7 1 2 3 4
4 5 6 7 8 9 10 8 9 10 11 12 13 14 5 6 7 8 9 10 11
11 12 13 14 15 16 17 15 16 17 18 19 20 21 12 13 14 15 16 17 18
18 19 20 21 22 23 24 22 23 24 25 26 27 28 19 20 21 22 23 24 25
25 26 27 28 29 30 31 29 30 31 26 27 28 29 30
Oct Nov Dec
S M Tu W Th F S S M Tu W Th F S S M Tu W Th F S
1 2 1 2 3 4 5 6 1 2 3 4
3 4 5 6 7 8 9 7 8 9 10 11 12 13 5 6 7 8 9 10 11
10 11 12 13 14 15 16 14 15 16 17 18 19 20 12 13 14 15 16 17 18
17 18 19 20 21 22 23 21 22 23 24 25 26 27 19 20 21 22 23 24 25
24 25 26 27 28 29 30 28 29 30 26 27 28 29 30 31
31
=============================== june99 =======================================
cat: Cannot open chap7ex/Cal/Months/june99: No such file or directory
================================ aug99 =======================================
cat: Cannot open chap7ex/Cal/Months/aug99: Permission denied
]]>