Strip off lesson materials that we do not teach

[lyashevska]

It is very hard to stay on time while teaching https://github.com/esciencecenter-digital-skills/git-lesson We should remove all unrelated/advanced stuff.

[svenvanderburg]

For episode 5 these are my notes:

Goal: Know that all commits are stored in your history. If you make a mess you can always go back, but you don’t have to remember the details how to do that exactly as long as you remember that it is possible! I will teach you a few important concepts and then you can google your way out of a mess!

Put the picture on the screen: There are 2 ways of referring to a commit:
• Relative to HEAD, where HEAD is an identifier for the most recent commit
• The commit ID -> a unique randomly assigned string, also called a commit hash
So let’s say we want to see the differences between HEAD2 and current state:
• git diff HEAD2 mars.txt
• git log
• git diff commit ID mars.txt
• git show commit ID mars.txt -> to see the file of that version of the software
Now let’s revert history
• git checkout commit ID mars.txt -> to set staging area to version of that commit
• git status
• git checkout HEAD mars.txt -> to go to most recent commit
Important: you never actually change history. You add another commit that changes the state to an older version.
Do exercises individually!