Exercises - Basic Concepts

  1. Create a repository, add (stage) and commit a file

mkdir repository 
cd repository 
git init 
nano file.txt 
git add file.txt 
git commit -m "This is quite interesting" 
2. Take a look at the stuff under the .git directory 

cd repository
tree .git 
git cat-file -p <hash> 

where is the various hash’es you can see with 

tree .git

Remember that the two-letter name of the subdirectory under objects-dir is included in the hash

  1. Make some changes.

Change one or more files. Add and commit. Make some changes. Add and commit.

Look at what happens in the .git tree

  1. Go to earlier commits and make a new branch

Try go back to an earlier commit with “git checkout ” 

Make come changes to a file there, or try adding a new file (and add+commit) 

Create a new branch from that commit: “git checkout -b second_branch” 

Find the hash of the commit the HEAD points to now  

cat .git/HEAD    
cat <path you got above> 
git cat-file -p <hash you just got from above command> 
  1. Go back on primary branch and merge the branches

Go back to the primary branch (main or master) with “git checkout main” or “git checkout master” 

Merge the new branch you created to master with “git merge –no-ff second_branch” (or whatever you called the new branch) 

Fix any conflict by going into the conflicting file(s) and removing the stuff you don’t want and also the git markers set there 

Add the fixed file and do “git merge –continue”  

Now look at what the HEAD is pointing to 

  1. Check out the commit tree  

You can also just try jump around in the commit tree with “git checkout ” and see how your working tree looks in various places (see that files are there or not, and with different content).

You get the list of hash’s and commit messages with “git log”