`git`¶

Worktrees¶

git worktree allows to have multiple working directories for a single repository. A worktree is the same as a normal repository, with the caviet that it is not possible to checkeout the same branch in multiple worktrees.

This is useful for working on multiple features in parallel, and avoids the need to stash changes or create multiple clones of the repository.

Create a new worktree¶

git worktree add -b <BRANCH> <PATH>

Convention¶

Clone the repository as <REPO>@<DEFAULT_BRANCH> and create worktrees for features as <REPO>@<FEATURE_BRANCH>. This is my own convention and is not a standard.

Aliases¶

git allows to create aliases for common commands.

Aliases can be created in the global configuration as follows:

git config --global alias.<ALIAS> <COMMAND>

My configuration

[alias]
    aa = add --all
    co = checkout
    cob = checkout -b
    cs = commit -signed --signoff
    discard = reset HEAD --hard
    fp = push --force-with-lease
    lol = log --graph --decorate --pretty=oneline --abbrev-commit
    lola = log --graph --decorate --pretty=oneline --abbrev-commit --all
    pr = "!f() { git fetch --force origin pull/$1/head:pr-$1; }; f"
    ps = push --signed
    root = rev-parse --show-toplevel
    st = status
    stag = tag -l --sort=v:refname
    uncommit = reset --soft HEAD^
    unstage = reset HEAD --
    wt = worktree

--force-with-lease

--force-with-lease is a safer alternative to --force that does not overwrite changes on the remote branch.

Identity¶

Signing commits¶

git supports signing commits with GPG keys.

Create GPG keys

gpg --default-new-key-algo rsa4096 --gen-key
gpg --armor --export <KEY_ID> # (1)!

Export public key. This can be used to add the key to GitHub, etc.

List available GPG keys

gpg --list-secret-keys --keyid-format=long

git config --global --unset gpg.format # (1)!
git config --global user.signingkey 3AA5C34371567BD2

One could use different key formats, such as SSH keys. Here we want to use GPG keys.

Signing keys can also be added to specific configurations or repositories. See Conditional configuration for separate work and personal configurations.

Signoff commits¶

git commit supports the --signoff option to add a signoff line to the commit message.

This is useful to indicate that the author has the right to submit the code.

git commit --signoff

Bisection¶

git bisect allows to find the commit that introduced a bug by performing a binary search.

To starti bisecting, use:

git bisect start

Then mark the current commit as bad:

git bisect bad

and mark a known good commit:

git bisect good <COMMIT>

git bisect will then checkout a commit in the middle of the range and ask to mark it as good or bad. This process is repeated until the commit that introduced the bug is found.

Cherrypicking changes¶

git add allows to interactively select hunks to stage form different files:

git add -p

This allows to create atomic commits by interactively selecting changes to be staged.

Large Repositories¶

When cloning large repositories, setting feature.manyFiles enables configuration options to improve performance:

git clone -c feature.manyFiles=true <REPO>

Diff for staged files¶

git diff does not show staged files in the diff.

The --staged option can be used to show the diff for staged files:

git diff --staged

Global ignore file¶

A global git ignore file can be created to ignore files across all repositories. This is useful for files that are specific to a certain workflow (.envrc, ...) or editor (.vscode, .idea), but not relevant to the repository.

The global ignore file can be created by setting the core.excludesfile configuration:

git config --global core.excludesfile ~/.config/git/ignore

Typically, the file is stored under ~/.config/git/ignore. To check if the global ignore file already exists, use:

git config --get core.excludesfile

Excluded files

.envrc
.vscode/
.idea/
core*
.null-ls_*

Conditional configuration¶

git supports conditional configurations to include configurations based on conditions. A common use-case is to have different configurations for work and personal repositories.

Separate work and personal configurations

If work repositories are under ~/git/work and personal repositories are under ~/git/oss, the following configuration can be used:

[includeIf "gitdir:~/git/work/"]
    path = ~/git/work/.config
[includeIf "gitdir:~/git/oss/"]
    path = ~/git/oss/.config

~/git/work/.config~/git/oss/.config

[user]
    name = John Doe
    email = john.doe@work.com

[user]
    name = John Doe
    email = john.doe@oss.org

git¶