How to GitHub

Local git

Things that are done locally in a single branch, not changing anything in the remote repository.

Set up

Set up name and email

git config --global user.name <NAME>
git config --global user.email <EMAIL>

Put directory under git revision control:

git init

Check config information

git config -l

Set url in the .git/config file

git remote set-url origin <address>.git

Push local branch to remote (master is the local branch name)

git push -u origin master

Basic commands

Steps of staging: Local repository – add –> staged – commit –> remote repository.

Viewing status

Check git status.
```
  git status
```

Check changes of files from two branches:

  git diff mybranch..master -- myfile.cs

View commit history:
```
  git log
```
Look at the new commit after clone:
```
  git log origin
```

Apply new changes

Add file to be commit:

git add

Re-do it (unstage a file)
git reset HEAD
Commit file and push it to remote repository:
```
 git commit -m "Say something"
```
remove commit and bring the file back as staged:
```
 git reset --soft HEAD~1		
```

Edit repository

change added (to be commit) file:

  git mv <OLD-FILENAME> <NEW-FILENAME>

git rm

retrieve commited file (to replace an unstaged file):
```
  git checkout --<FILENAME>		
```

Local Git management

Copy a folder (with added/submitted files):
```
  git clone exited_folder new_folder
```

Save log (a diff is called a patch):

  git format-patch --stdout origin > mywork.mbox

Remote GitHub

Clone: to copy a complete repository

  git clone https://github.com/Ooohu/Cross-section-calculator.git

Pull: fetch + merg
```
  git pull <REMOTENAME> <BRANCHNAME>
```
Fetch: to retrieve a file
```
  git fetch <REMOTENAME>
```
Merge: combine remote-tracking branch with local branch:
```
  git merge <REMOTENAME>/<BRANCHNAME>
```

Branching

Branching steps:

Reference

Create a new branch for a new particular issue; do this at your master branch.
Push the new branch (to overwrite the original branch), or based on the original branch, based on the new branch.

Single Branching

Look at current branches:

git branch

Create a new branch and switch to it:

$ git checkout -b <new_branch_name>

which is equivalent the following

$ git branch <new_branch_name>
$ git checkout <(that)new_branch_name>

Clone a specific branch of git

git clone --single-branch --branch feature/miniboone_Nov20 https://github.com/Ooohu/hellstroms_hive.git

Create a new branch

git branch <branch_name>

Switch to a branch

git checkout <branch_name>

Merge branch (bring the other branch into current branch)

git merge <the other branch>

Merge branch from another repository

git remote add <nickname_for_the_repository> <repository.git> #connect the repository
git fetch <nickname_for_the_repository> #get the branches
git merge <nickname_for_the_repository>/branch

Delete branch

git branch -d <branch_name>

Rename a local branch

git branch -m <oldname> <newname>
# or rename the current branch:
git branch -m <newname>

Check tag

git tag

Regrets a commit:

git rebase -i <target-commit>~1  # start rebase from the previous commit of target commit
	# then choose what action to take by deleting a line
git push -f origin HEAD #Hide your mistake by pushing it to the repository

Cross Branching

Checkout a remote branch git checkout -b <new_branch_name> origin/<target_branch>

Push a feature branch to target branch (will overwrite others’ work):

$ git push -u <target branch> <feature branch>

Check the difference beteen branches:

$ git diff <branch1>..<branch2>

Checkout specific file from other branches:

git fetch
git checkout -m master <file name>

Merge a file from other branch:

git checkout -p origin/master -- bdt_file.h

-p mode lets you choose one path out of a status like selection. After choosing the path, it presents the diff between the index and the working tree file and asks you if you want to stage the change of each hunk. You can select one of the following options and type return:

  y - stage this hunk
  n - do not stage this hunk
  q - quit; do not stage this hunk nor any of the remaining ones
  a - stage this hunk and all later hunks in the file
  d - do not stage this hunk nor any of the later hunks in the file
  g - select a hunk to go to
  / - search for a hunk matching the given regex
  j - leave this hunk undecided, see next undecided hunk
  J - leave this hunk undecided, see next hunk
  k - leave this hunk undecided, see previous undecided hunk
  K - leave this hunk undecided, see previous hunk
  s - split the current hunk into smaller hunks
  e - manually edit the current hunk
  ? - print help

Get a forked branch

At a branch, one can access to a forked branch git fetch <forked_repo_url> <branch>

Use these commands to get branches from other user:

git remote add <theirusername> <https://github.com/theirusername/reponame>
git fetch <theirusername>
git checkout -b <mynamefortheirbranch> <theirusername/theirbranch>

Fork a branch

After you have cloned a branch and make modification, you want to save the progress. You can fork a branch, i.e. create a repo in your account;

In your local, rename your origin remote to upstream

`git remote rename origin upstream`

Add a new origin

`git remote add origin <forked repository address>`

Fetch & push

    git fetch origin
    git push origin

Now, your repository will change to your forked repository.

You local branch can now be pushed to the forked repository via

`git push -u origin <local branch name>

Trouble Shooting

Username

Error looks like:

error: The requested URL returned error: 403 Forbidden while accessing

Change your url in .git/config, chenge the address to the format: <username>@github.com/<repository> or git@github.com:Ooohu/<repository>

Or try this git config --get-all <name>

Permission denied (publickey). Permission denied (publickey). fatal: The remote end hung up unexpectedly

ref Generate ssh key and copy it to github account (in the setting session)
cd ~/.ssh
ssh-keygen
The key will be found in:
~/.ssh/id_rsa.pub
Then build the ssh connection
ssh -T git@github.com
Connect github via SSH: git remote set-url origin git@github.com:USERNAME/REPOSITORY.git