debugging

Use journalctl on Linux or log show on macOS to get the super user accesses and commands in the last day. If there aren’t any you can execute some harmless commands such as sudo ls and check again.

When I run log show --last 1d, it keeps running for along time. I don’t know how long it make take, so I will just execute harmless sudo ls to check the log.

Lecture05. Command-line Environment

Job control

From what we have seen, we can use some ps aux | grep commands to get our jobs’ pids and then kill them, but there are better ways to do it. Start a sleep 10000 job in a terminal, background it with Ctrl-Z and continue its execution with bg. Now use pgrep to find its pid and pkill to kill it without ever typing the pid itself. (Hint: use the -af flags).

Lecture 03. Editors (Vim)

Complete vimtutor. Note: it looks best in a 80x24 (80 columns by 24 lines) terminal window.

It is a tutorial for beginners of vim. I will just put some notes which are not mentioned in course here.

• U command: When we press u in normal mode, we can undo the last command. What U does is fixing a whole line.

• Ctrl + G: show your location in the file and the file status. Type the linenumber you want to go, then press G, then you are there.

Intro

The process of drawing a simple relation graph in python can be broken down into 2 steps.

1. Define a graph.
2. Draw a graph.

Step 1. Define a graph

In this step, we will use the networkx package.

Install tutorial

If you are using conda, you can just type conda install networkx

If you are using pip, you can just type pip install networkx

Nodes

First of all, you need to create a graph.

Lecture 01. Shell

Create a new directory called missing under /tmp