Mastering Git: How to Create New Branches from Previous Commits (Using Git Bash)

Getting Started with Git Bash

Before we begin, make sure you have Git installed on your machine and are comfortable using the command line. If you’re new to Git Bash, here’s a quick rundown:

1. Open Git Bash on your machine (it’s usually located in the Start menu on Windows or in the Applications/Utilities folder on Mac).
2. cd command (e.g., cd ~/myproject).
3. Verify that you’re in the correct repository by running the command git status.

Finding the Right Commit

The first step in creating a new branch from a previous commit is to find the commit you want to branch from. You can do this using the git log command:

$ git log
commit 123456789abcdef (HEAD -> main)
Author: Your Name 
Date:   Fri Mar 12 14:30:00 2023 +0100

    Add new feature
commit 23456789abcdef
Author: Your Name 
Date:   Thu Mar 11 10:00:00 2023 +0100

    Fix bug
commit 3456789abcdef
Author: Your Name 
Date:   Wed Mar 10 16:00:00 2023 +0100

    Initial commit

In this example, we can see a list of commits, each with a unique hash (the long string of characters starting with “123456789abcdef”). We can use this hash to reference the commit.

Creating a New Branch

Now that we’ve found the commit we want to branch from, let’s create a new branch using the git branch command:

$ git branch new-feature 23456789abcdef

In this example, we’re creating a new branch called “new-feature” from the commit with the hash “23456789abcdef”. You can replace “new-feature” with any name you like for your new branch.

Switching to the New Branch

To start working on your new branch, you’ll need to switch to it using the git checkout command:

$ git checkout new-feature

This will move you to the new branch, and any changes you make will be committed to this branch instead of the main branch.

Viewing Branches

At any time, you can view all your branches using the git branch command with the -a option:

$ git branch -a
  main
* new-feature
  remotes/origin/main

This will show you a list of all your local and remote branches. The asterisk (*) indicates the branch you’re currently on.

Merging Changes from Other Branches

Sometimes, you’ll want to incorporate changes from another branch into your new branch. You can do this using the git merge command:

$ git checkout new-feature
$ git merge main

This will merge the changes from the main branch into your new-feature branch.

Delete a Branch

When you’re finished with a branch, you can delete it using the git branch command with the -d option:

$ git branch -d new-feature

This will delete the branch, but only if it’s fully merged into another branch. If the branch has unmerged changes, you’ll need to use the -D option instead:

$ git branch -D new-feature

Be careful when deleting branches!}