ECE 2524 - Permissions and Processes

ECE 2524

Introduction to Unix for Engineers

Permissions and Processes

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Office Hours

Based on feedback I will move my Monday office hours to some time on Thursday. I will make another announcement when I finalize a time.

Quiz Feedback

  1. Why is 400 the minimum permissions needed by jump.txt?
  2. difference between ps x and ps aux
  3. why won’t kill 1337 work?

We’ll do some experiments to check all of these.

File Permissions

  1. inspect the permissions of a compiled binary (e.g. motr)
  2. inspect hte permissions of a regular text file (e.g. motr.c)
  3. manipulate permissions of files used for input/output redirection

TODO

We didn’t make it through these list items in the ‘File Permissions’ section that I had on my notes. We will probably get through some of them next class.

  1. try to run motr.c as a command
  2. write a simple build script
  3. try to run it
  4. set permissions
  5. run it

Processes and Signals

Source can be found in /usr/share/src/week5/

  1. What does the process ‘see’? (we didn’t do this)
    • inspect argv with redirection
  2. infinite_hello example
    • Try ^C
    • Try kill

Setup SSH Keys (we didn’t make it this far)

$ ssh-keygen

Inspect the permissions for the ~/.ssh/ directory and its files.