User identity settings (username and email)

User Identity Setup (Username and Email)

Git, as a distributed version control system, uses user identity as the core identifier for commits. Correctly configuring the username and email ensures traceability in collaboration and serves as the basis for platform contribution statistics. Incorrect or missing identity information may result in commits not being associated with the correct account.

Global vs. Local Configuration

Git provides two levels of identity configuration:

1. Global Configuration (applies to all repositories):

git config --global user.name "Your Username"
git config --global user.email "your.email@example.com"

2. Local Configuration (applies only to the current repository):

git config user.name "Project-Specific Username"
git config user.email "project@example.com"

Priority rule: Local configuration > Global configuration. To check configurations, use:

git config --list --show-origin

Enterprise Development Scenario Example

Assume a developer participates in both company projects and open-source projects:

# Global configuration for personal account (default)
git config --global user.name "dev_zhang"
git config --global user.email "zhang@personal.com"

# Override configuration in the company project directory
cd ~/company/project-awesome
git config user.name "Engineer Zhang"
git config user.email "zhang.san@company.com"

Multi-Email Management Tips

When using different platforms, match the registered email:

Configuration Verification and Troubleshooting

Verify the currently active configuration:

git config user.name && git config user.email

Common issue resolution:

1. Commits show incorrect identity:

# Modify the author info of the most recent commit
git commit --amend --author="New Username <new.email@example.com>"

2. Bulk modify historical commits (risky operation):

git filter-branch --env-filter '
OLD_EMAIL="old.email@example.com"
CORRECT_NAME="Correct Name"
CORRECT_EMAIL="correct.email@example.com"
if [ "$GIT_COMMITTER_EMAIL" = "$OLD_EMAIL" ]
then
    export GIT_COMMITTER_NAME="$CORRECT_NAME"
    export GIT_COMMITTER_EMAIL="$CORRECT_EMAIL"
fi
if [ "$GIT_AUTHOR_EMAIL" = "$OLD_EMAIL" ]
then
    export GIT_AUTHOR_NAME="$CORRECT_NAME"
    export GIT_AUTHOR_EMAIL="$CORRECT_EMAIL"
fi
' --tag-name-filter cat -- --branches --tags

Automated Configuration Solutions

Conditional configuration via .gitconfig file:

[includeIf "gitdir:~/work/"]
    path = .gitconfig-work
[includeIf "gitdir:~/open-source/"]
    path = .gitconfig-opensource

Example companion file (~/.gitconfig-work):

[user]
    name = Company Account
    email = name@corp.com
    signingkey = ABCD1234

Security Considerations

1. Protecting sensitive information:

   • Avoid committing configurations containing internal emails to public repositories
   • Use git secret to encrypt sensitive configurations

2. Corporate compliance requirements:

# Example pre-commit hook to enforce corporate email domain
#!/bin/sh
CORPORATE_DOMAIN="company.com"
CURRENT_EMAIL=$(git config user.email)

if [[ ! "$CURRENT_EMAIL" =~ "@$CORPORATE_DOMAIN"$ ]]; then
    echo "Error: Must use company email ($CORPORATE_DOMAIN)"
    exit 1
fi

Cross-Platform Identity Unification

Associate keys with different platforms via SSH configuration:

# ~/.ssh/config
Host github.com
    User git
    IdentityFile ~/.ssh/id_ed25519_github
    IdentitiesOnly yes

Host gitlab.company.com
    User git
    IdentityFile ~/.ssh/id_rsa_company
    IdentitiesOnly yes

Matching Git configuration:

[url "git@github.com:"]
    insteadOf = https://github.com/
[url "git@gitlab.company.com:"]
    insteadOf = https://gitlab.company.com/

GUI Tool Configuration

Identity configuration in mainstream IDEs:

VSCode Example:

1. Open settings panel (Ctrl+,)
2. Search for "git config"
3. Modify via GUI:

{
    "git.enableCommitSigning": true,
    "git.defaultCloneDirectory": "~/Projects"
}

IntelliJ IDEA Configuration Path:

File -> Settings -> Version Control -> Git

Advanced Scenario: Temporary Identity Override

Use a special identity for a single commit:

git -c user.name="Temporary User" -c user.email="temp@example.com" commit -m "Emergency fix"

Override via environment variables:

GIT_AUTHOR_NAME="CI System" GIT_COMMITTER_NAME="CI System" git commit -m "Automated build"