Git Guide

Overview
Merging
Removing
- Removing Files
- Deleting a Local Branch
Renaming a Branch
Stashing Changes
Undoing a Commit
Undoing one or more Pushes
Misc

Overview

This document provides a compilation of useful Git commands.

Merging

Merge all files from source branch into target branch

git checkout target-branch
git merge source-branch

Alternate method (same results)
```
git merge source-branch target-branch
```

Merge single file from source branch into target branch

git checkout source-branch/path/to/file
git commit
git push

Renaming a Branch

Rename your local branch
```
git branch -m new-name
```
Delete old-name remote branch and push the new-name local branch
```
git push origin :old-name new-name 
```
Reset the upstream branch for the new-name local branch
```
git push origin -u new-name 
```

Alternate method (same results)

git branch -m old_branch new_branch         # Rename branch locally
git push origin :old_branch                 # Delete the old branch
git push --set-upstream origin new_branch   # Push the new branch, set local branch to track the new remote

Removing

Removing Files

Remove all untracked files
```
git clean -f
```
Remove all untracked files and directories
```
git clean -fd
```
Get rid of all changes on your local branch
```
git reset --hard HEAD
```

Reset single file in local branch to remote branch

git checkout remote-branch -- file1/to/reset file2/to/reset
git commit
git push

Deleting a Local Branch

Sooner or later, you'll have a ton of old branches that have been merged on your local instance of a repo. To clean things up, use the following command:

git branch -d name-of-local-branch-to-delete

To force-delete a branch that has not been completely merged, you can use:

git branch -D name-of-local-branch-to-delete

Stashing Changes

Stash all changes to the repo
```
git stash
```
Delete the top stash
```
git stash drop
```
Delete a specific stash
```
git stash drop stash@{n}
```
Grab all code from last stash but don't remove it from the stash list
```
git stash apply
```
Grab all code from last stash and remove it from the stash list
```
git stash pop
```
Note: git stash pop = git stash apply + git stash drop

Undoing a Commit

Only undo the act of committing and leave everything else intact (do not unstage files):

git reset --soft HEAD^

Undo the act of committing and unstage all files, but leave the work tree (your files) intact:

git reset HEAD^

Discard all changes and reset everything to the previous commit:

git reset --hard HEAD^

Undoing one or more Pushes

First, reset the remote branch:

git push -f origin commit-hash-to-rewind-to:branch_name

Then, reset your local branch so it's at the same place as the remote:

git reset --hard commit-hash-to-rewind-to

IMPORTANT NOTE: Be very sure that this is absolutely essential for your purposes before doing it! You are rewriting history!

Misc

Fix errors that contain the phrase cannot lock ref
```
git remote prune origin
```
Show a history of what was committed and when
```
git log
```
HEAD refers to the current commit, which is usually the tip of the currently checked-out branch. HEAD^ is the commit before the current one. (In Git, the ^ means "the one before").