Using multiple GitHub accounts on a local machine requires managing SSH keys and configuring Git to use the correct credentials for each account. Here's how you can do it:

Step 1: Generate SSH Keys for Each Account

1. Generate a New SSH Key:

   • Open your terminal.

   • Run the following command to generate a new SSH key (replace email@example.com with the email associated with the GitHub account):

     ssh-keygen -t rsa -b 4096 -C "email@example.com"

   • When prompted, save the key with a unique name /c/Users/USER_NAME/.ssh/id_rsa_account1

     Enter file in which to save the key (/c/Users/USER_NAME/.ssh/id_rsa): /c/Users/USER_NAME/.ssh/id_rsa_account1

2. Ensure the ssh-agent is running by executing:

   eval "$(ssh-agent -s)"

3. Add the SSH Key to the SSH Agent:

   ssh-add ~/.ssh/id_rsa_account1

4. Copy the SSH Key to GitHub:

   • Copy the SSH key to your clipboard:

     clip < ~/.ssh/id_rsa_account1.pub

   • Go to your GitHub account settings, then to "SSH and GPG keys," and add the key.

5. Repeat the above steps for the second (or additional) GitHub account. Be sure to name the keys differently (e.g., id_rsa_account2).

Step 2: Create a Config File for SSH

1. Edit the SSH Config File:

   • Open your ~/.ssh/config file in a text editor. If it doesn’t exist, create it.

2. Add Configurations for Each Account:

   • Add the following configuration, replacing the paths and usernames as needed:

     # Account 1
     Host github-account1
       HostName github.com
       User git
       IdentityFile ~/.ssh/id_rsa_account1
     
     # Account 2
     Host github-account2
       HostName github.com
       User git
       IdentityFile ~/.ssh/id_rsa_account2

Step 3: Clone Repositories Using the Correct Account

When cloning repositories, specify the host alias you defined in your SSH config:

• For the first account:

  git clone git@github-account1:username/repo.git

• For the second account:

  git clone git@github-account2:username/repo.git

Step 4: Configure Git for Each Repository

Inside each repository, you can set the user name and email to match the corresponding GitHub account:

git config user.name "Your Name"
git config user.email "email@example.com"

You can also set this globally if you prefer to have a default identity:

git config --global user.name "Your Default Name"
git config --global user.email "default@example.com"

Step 5: Using Different Accounts for Push and Pull

When working with existing repositories, make sure to change the remote URL to use the correct SSH alias:

git remote set-url origin git@github-account1:username/repo.git

Summary

• SSH keys: Create a unique SSH key for each GitHub account.
• SSH config: Set up your ~/.ssh/config file to use different keys for each account.
• Cloning: Use the appropriate SSH alias to clone repositories.
• Git config: Set user name and email per repository or globally as needed.

This setup allows you to manage multiple GitHub accounts on the same machine without conflicts.