Lecture 3 — Computer systems and the command line

Tue 13 Oct 2026 · Boris Bolliet

Slides Notes Self-test Recording

Demonstration files

File	View	Download	Colab
C1.csv
C10.csv
C2.csv
C3.csv
C4.csv
C5.csv
C6.csv
C7.csv
C8.csv
C9.csv
fetch_runs.sh
period.py
runs.txt
summarise.sh

curl -LO https://teaching.borisbolliet.io/c1-2026/materials/class03-demo.zip && unzip class03-demo.zip

Data: the ten chemostat runs C1–C10 of B. Blasius, L. Rudolf, G. Weithoff, U. Gaedke and G. F. Fussmann, Long-term cyclic persistence in an experimental predator–prey system, Nature 577, 226–230 (2020); data set on figshare, doi:10.6084/m9.figshare.10045976 (CC BY 4.0).

runs.txt lists the figshare file id of each run (from https://api.figshare.com/v2/articles/10045976/files); fetch_runs.sh downloads them, and the CSV files are shipped here so that the demonstration also runs without a network connection. summarise.sh prints the number of samples and the peak algae density of one run; period.py is the Lecture 1 script used on the permissions frame.

Content

1. The stored-program computer
   • Computing before the stored program
   • The von Neumann model
   • The memory hierarchy
   • Core memory and disks
2. The operating system and the shell
   • The operating system and the kernel
   • The shell
   • Processes and environment variables
3. The file system
   • The file system tree
   • File-system formats
   • Files and directories from the shell
   • The data file from the shell
   • Permissions
4. Shell scripts
   • Scripts, the shebang and arguments
   • Redirection and exit status
   • Loops over the ten runs

Exercises with solutions