CSE39 · CSE foundations & data structures
Linux Permissions & Processes
Read rwx permissions, change them safely and inspect running processes on a practice Linux machine.
🎯 You will learn to
- Read rwx for user, group and others
- Use chmod with numbers
- List and stop processes
📘 Guided lab
This mission is a guided walkthrough: follow the steps on your own computer or practice account. The in-browser simulator for it is planned for a later release.
✅ Steps & checkpoints
🗺️ Linux permissions and processes
The kernel checks owner, group and others bits before a process may read, write or run a file.
The 2D diagram shows the exact flow, ports and trust boundaries. The 3D scene is a concept view of the same parts; packets travel along the same arrows.
🤔 Think about it
Why is chmod 777 a bad fix for "permission denied"?
🛡️ Safety & cost
Simulations and in-browser runtimes only.
🧹 Cleanup
Nothing to clean up.
📚 Reference documents
- Linux man pages · man7.org
- Introduction to Algorithms (6.006) · MIT OpenCourseWare
- The Python Tutorial · Python
- SQL as understood by SQLite · SQLite
Official sources, checked on 5 Nov 2026. Cloud services change often; check the official page before relying on a feature. All references