# Git Tips

## Amend a Commit

```
git commit -a -m "wrong commit, needs changes"    # commit only staged changes, miss untracked changes
git add forgotten_file edited_file ...            # stage the changes to fix previous commit
git commit --amend --no-edit                      # commit staged changes, without editing commit message
git commit --amend -m "revised commit message"    # edit commit message, and commits staged changes if any

git commit --amend --reset-author                 # revise commit author info (for when committed as wrong user)
```

## Bypass Pre-commit Hooks

```
git commit --no-verify    # bypasses commit-msg hooks too
```

## Configure User

```
git config user.name="John Doe"                  # add --global flag for global configuration
git config user.email="jd@example.com"           # add --global flag for global configuration

git config author.name="John Doe"                # for use when author is a different user
git config author.email="mail@example.com"       # for use when author is a different user

git config committer.name="John Doe"             # for use when committer is a different user
git config committer.email="mail@example.com     # for use when committer is a different user
```

`GIT_AUTHOR_NAME`, `GIT_AUTHOR_EMAIL`, `GIT_COMMITTER_NAME`, `GIT_COMMITTER_EMAIL` and `EMAIL` environment variables override above settings.

## Undo a Commit

- `revert` creates new commit(s) to undo commit(s).
- `reset` discards a commit.

Following command discards the last commit completely.

```
git reset --hard HEAD~1
```