Git

Created: August 10, 2020

Command	Description
`git init`	Create a local repository in the current directory
`git clone`	Clone a remote repository.
`git add {FILE\|GLOB}`	Tell git to track a file.
`git commit`	Commit any changes.
`git status`	Shows status of files. What has been changed, etc.
`git branch`	Show which branch is being worked on locally.
`git merge`	Merge branches.
`git pull`	Pull changes from the remote repository to the local machine.
`git push`	Updates the remote repository with anything committed locally.
`git clean`	Removed untracked files and directories. Use carefully.

Git internal data is stored in .git/.

Set Up a New Repository

mkdir REPO_NAME
cd REPO_NAME
echo "SOMETHING" > README.md
git init                       
git add FILES
git commit -m "MESSAGE"       # a local repo now exists
git remote add origin git@github.com:JamesLochhead/SOMETHING.git # needs to exist
# now synced with GitHub
git push -u origin master

.gitignore

A file within the top-level of the git directory containing globs for files/directories that should be ignored. One line per pattern.

Semantic Versioning

Peformed using tags:
```
git tag -a vX.Y.Z -m "MESSAGE"
```
To push tags upstream:
```
git push --tags
```
The describe command can be used to get useful information about tags:
```
git describe --tags --long
```
The number after the tag, between the two en dashes, represents the number of commits since the last tag.

Branching

To create a new branch:
```
git checkout -b BRANCH_NAME
```

This is shorthand for:

git branch BRANCH_NAME
git checkout BRANCH_NAME

You cannot change branches with uncommitted changes.

Merge a Branch with Master

Commit changes before using checkout.
Change to master:
```
git checkout master
```
Merge BRANCH with master:
```
git merge BRANCH
```

View untracked files and directories

git clean -xdn

Use carefully. Without the n flag, it removes all untracked files (-x) and all untracked directories (-d).

Remove a file from git

From git and the local filesystem:

git rm FILE

From just git:

git rm --cache FILE

Check for changes in a Git remote

git fetch origin

See the commit hash of HEAD

git rev-parse HEAD

Reset to a specific commit

git reset --hard COMMIT
git reset --hard HEAD~2

Revert a file to HEAD

git checkout -- FILE

Checkout a file from a different branch

git checkout BRANCH -- FILE

Show differences between branches

git diff BRANCH1..BRANCH2

Show files that are different between branches

git diff --name-status BRANCH1..BRANCH2

Delete a local branch

git branch -d BRANCH

Delete a remote branch

git branch -d BRANCH
git push origin --delete BRANCH

Merge and squash

git merge --squash BRANCH