hook Git Command Guide

The git hook command provides a programmatic interface to run Git hooks, enabling scripted execution of hook logic and integration with external tools that need to trigger hook behavior.

git hook Syntax:

git hook run [--ignore-missing] [--to-stdin=<path>] <hook-name> [-- <hook-args>...]

Command Subcommands:

Subcommand	Description
run	Execute the specified hook

Options:

Option	Description
--ignore-missing	Don’t error if hook doesn’t exist
--to-stdin=<path>	Stream file content to hook’s stdin
<hook-name>	Name of hook to run (see githooks(5))
-- <hook-args>	Arguments to pass to hook script

Caution

Hook execution depends on hook script existence and permissions. Environment matches hook execution context. Use —ignore-missing for optional hook runs.

git hook Command Samples:

Run pre-commit hook manually for testing

git hook run pre-commit

Executes the pre-commit hook if it exists, simulating normal commit workflow.

Test commit-msg hook with custom message

echo "feat: add new feature" | git hook run --stdin-msg commit-msg

Test commit message validation with specific message content.

Run hook with custom arguments

git hook run prepare-commit-msg --squash HEAD

Execute prepare-commit-msg hook as if preparing squash commit message.

Ignore missing hooks in build scripts

git hook run --ignore-missing pre-commit || echo "No pre-commit hook"

Safe hook execution that doesn’t fail if hook doesn’t exist.

Stream file to hook stdin

git hook run --to-stdin=commit-msg-file.txt commit-msg

Run commit-msg hook with file contents streamed to stdin.

Test hook in different repository context

cd /path/to/repo && git hook run post-commit

Test hook execution in specific repository context.

Validate hook logic programmatically

if git hook run --ignore-missing validate-branch-name -- "$branch"; then
    echo "Branch name valid"
else
    echo "Branch name rejected"
fi

Use hook for validation logic in scripts.

Tip

Use for testing hook behavior and integration development. Combine with —ignore-missing for robustness in automation.

How does git hook differ from direct hook execution?

git hook provides standardized interface with proper environment setup, argument parsing, and error handling that direct execution lacks.

When should I use git hook vs calling hooks directly?

Use git hook for programmatic hook execution, integration testing, and when you need hook functionality without triggering full Git operations.

Can git hook run server-side hooks?

git hook is designed for client-side hooks. Server-side hooks execute automatically during push operations, not via git hook command.

What’s the use case for —to-stdin option?

Feed specific input to hooks that read from stdin, allowing controlled testing with known input data instead of Git-generated content.

How do I test hook exit codes programmatically?

Hook exit codes indicate success/failure - use git hook return codes in scripts for validation logic and conditional execution.

Can git hook modify Git repository state?

Hooks executed via git hook can modify repository state same as normal operation - pre-commit hooks can stage files, post-commit hooks can run cleanup.

What’s the difference between hook execution in git hook vs normal Git？

Environment variables match normal execution, but some Git operation context (like staged changes) may differ if not called during actual Git operations.

How do I debug hook execution with git hook?

Run hooks manually with git hook, add debugging output to hook scripts, check environment variables and working directory during execution.

Can external tools use git hook for integration?

Yes, git hook provides command-line API for external tools to trigger Git hook logic programmatically, useful for IDE integrations and CI systems.

What’s the security implications of git hook?

Hooks run as the user executing Git commands. No additional security beyond user’s permissions; hooks can execute arbitrary code with user’s privileges.

Applications of the git hook command

1. Hook Testing: Validate hook behavior before deployment
2. Integration Development: Programmatic Git workflow integration
3. Automated Validation: Hook-based validation in build systems
4. Repository Management: Custom repository administration tools
5. CI/CD Integration: Trigger Git logic in continuous integration workflows
6. Scripted Operations: Automated Git repository maintenance scripts