In this article you learn that how you can change author name/email using also how you can change username? and git update global user values 

Change the author and committer name/email for multiple commits?

To change the author and/or committer name and email for multiple Git commits, you can use the "git rebase" command with the "--edit-toplevel" option. Here's an example:

1. Checkout the branch you want to modify: "git checkout "
2. Use the "git rebase" command to rewrite the branch's history: "git rebase -i HEAD~"
3. In the interactive rebase editor, replace "pick" with "edit" for the commits you want to change.
4. After you save and exit the editor, use the "git commit --amend" command to change the author and/or committer name and email: "git commit --amend --author='New Author Name new.author@email.com' --committer='New Committer Name new.committer@email.com'"
5. Continue the rebase with the "git rebase --continue" command.

Note: Rewriting Git history is a potentially dangerous operation that can cause conflicts and loss of data. Make sure to backup your data before you start and understand the consequences of rewriting Git history.

git update global username email and update git update config variables

To update your global Git username and email, you can use the following Git commands:

1. To set your global Git username: "git config --global user.name 'Your Name'"
2. To set your global Git email: "git config --global user.email 'your.email@example.com'"

This will update your global Git configuration and will be applied to all future commits. If you want to set a different username and email for a specific repository, you can run these commands within that repository's directory.

git config --global user.name 'Your Name'
git config --global user.email 'your.email@example.com'

what are Git configuration variables

You can update Git configuration variables using the "git config" command. Here are some examples:

1. Update global username: "git config --global user.name 'Your Name'"
2. Update global email: "git config --global user.email 'your.email@example.com'"
3. Update repository-specific username: "git config user.name 'Your Name'"
4. Update repository-specific email: "git config user.email 'your.email@example.com'"

Note: The "--global" option is used to set a configuration value that applies to all repositories on your computer. If you omit the "--global" option, the configuration value will only apply to the current repository.


How to change the commit author for a single commit?

To change the author of a single Git commit, you can use the "git rebase" command with the "--interactive" (or "-i") option. Here's an example:

1. Check out the branch containing the commit you want to change: "git checkout <branch>"
2. Use the "git rebase" command to interactively rebase the branch: "git rebase -i HEAD~<number of commits>"
3. In the interactive rebase editor, replace the word "pick" with "edit" for the commit you want to change.
4. After you save and exit the editor, use the "git commit --amend" command to change the author of the commit: "git commit --amend --author='New Author Name new.author@email.com'"
5. Continue the rebase with the "git rebase --continue" command.

Note: Rewriting Git history is a potentially dangerous operation that can cause conflicts and loss of data. Make sure to backup your data before you start and understand the consequences of rewriting Git history.