CS 2000 - Fall 2025.

Driver-less car prank Jimmy Kimmel Live.

Logical problem of the day

https://pollev.com/slade You may also download the app to your phone. Use the "slade" poll id.

Chart of the Day

Poem of the Day

**Shell Scripts**

In the terminal's glow, where commands come alive,
The shell script awakens, begins to thrive.
With shebang declaring its Bash-born birth,
It orchestrates chaos across digital earth.

#!/bin/bash it proudly proclaims at the top,
A conductor's baton that will never stop.
Variables dancing with dollar signs dressed,
$1, $2, parameters put to the test.

For loops spiral through files in neat rows,
While if-then logic decides where it goes.
Pipes channel data like rivers of text,
grep, sed, and awk—what wonder comes next?

chmod +x grants wings to the code,
Executable magic on filesystem road.
From simple backups to complex routines,
These scripts are the oil in computing machines.

Error codes whisper of success or defeat,
Exit status zero makes the cycle complete.
In crontab's embrace, they run through the night,
Silent guardians working beyond human sight.

Oh humble shell script, so elegant and lean,
The glue between programs, mostly unseen.
In UNIX tradition, you do one thing well—
A digital haiku in terminal's shell.

Canvas Quiz of the Day (need daily password)

Click for today's quiz.

Lecture 24: Cryptography + UNIX.

Administrivia

Announcements

Final Exam

Here is a practice final exam and practice final solutions.

Here are the important concepts from Stamp:

• CIA
• Caesar cipher
• Substitution cipher
• Transposition cipher
• Kerckoff's Principle
• Complexity of brute force attacks (exhaustive key search)
• Secure vs insecure ciphers
• One-time pad

Shell scripts: I might ask you to write a shell script. You should know the for loop.

The following topics were part of this course and are in scope for the final:

• Python
• recursion
• list comprehensions
• memoization
• decorators
• exceptions
• UNIX including bash shell scripts
• regular expressions
• object oriented programming
• data structures: stacks, queues, hash tables, heaps
• SQL
• Machine architecture
• Python byte code
• cryptography

If your grade on the final exam is higher than your lower midterm grade, it will replace that grade. The quality of mercy is not strained.

Alas, we did not get to machine learning. See scikit learn aka, sklearn. Python module for machine learning. Machine learning jupyter notebook

Cryptography

See hw7hints.py You may need to install the module: wordsegment. (May need to run on lion using python 3.10. Sigh.)

pip install wordsegment
  

Getting to know UNIX