====== Git Tips and Tricks ======

===== Git Setup =====

The values you set here will be used as defaults when you set up local repositories and connect to remote repositories.

<code bash>
git config --global user.name "Your Name Here"
 
git config --global user.email "your_email@example.com"

git config --global init.defaultBranch main
 
git config --list
</code>

Set values for a specific repository (you must be in the root directory of the repository when you issue these commands):

<code bash>
git config --local user.name "Your Name Here"
 
git config --local user.email "your_email@example.com"
</code>

===== Initialization =====

==== Initialize a local Git repository ====

<code bash>
cd <directory to add to source control>
 
git init
</code>

==== Initialize a local Git repository, based on a remote repository ====

This uses [[https://en.wikipedia.org/wiki/GitHub|Github]] as an example.

  - Open terminal.
  - Create directory: mkdir ~/test-repo (Change “test-repo” to whatever you want.)
  - Change to the new directory: cd ~/test-repo
  - Initialize a local Git repository: git init
  - Point your local repository to the remote repository: git remote add origin https://github.com/yourUserNameHere/test-repo.git

===== Sync local repo with remote =====

To sync your local repository with its associated remote repository, issue this command:

<code bash>
git fetch origin
</code>

You may need to retrieve and approve remote changes to force them into your local copy:

<code bash>
git checkout master
 
git merge origin/master
</code>

You should also be able to use “pull” to combine the fetch and merge into a single operation:

<code bash>
git pull origin
</code>

===== Clone a copy of a remote repository =====

<code bash>
cd <local_directory>
 
git clone https://github.com/<username>/<repository_name.git>
</code>

(This example uses GitHub. Modify it to whatever remote hosting site you need.)

===== Adding new files to a repository =====

This should be done before committing.

Add a single file:

<code bash>
git add <filename>
</code>

Add all new files:

<code bash>
git add
</code>

Update tracking for files that changed names or were deleted:

<code bash>
git add -u
</code>

To do both, use this:

<code bash>
git add -A
</code>

===== Commit changed files to a repository =====

After files have been added, you can commit them to be saved as an intermediate version:

<code bash>
git commit -m "message"
</code>

…where “message” is a useful description of what you did.

This only updates your local repo. If your repo is associated with a remote repository, the remote repo is not updated in this step.

===== Update remote repository =====

If you have saved local commits and you would like to update an associated remote repository:

<code bash>
git push
</code>

===== Branching =====

If you are working on a project with a version being shared by many people, you may not want to edit that version.

You can create a branch (and switch to it) with this command:

<code bash>
git checkout -b branchname
</code>

List available branches:

<code bash>
git branch
</code>

List remote branches:

<code bash>
git branch -r
</code>

List all branches:

<code bash>
git branch -a
</code>

(The branch you are on is marked with an asterisk.)

Refresh local list of remote branches:

<code bash>
git remote update origin --prune
</code>

If you have a remote branch, and you need to create/sync with it locally, do the following.

First, list remote branches, and note the name of the branch you want to create locally:

<code bash>
git branch -a
</code>

If, for example, the remote branch is named ‘remotes/origin/dev’, you can then create it locally, sync it, and switch to it with the following command:

<code bash>
git checkout -t remotes/origin/dev
</code>

If you want control over the naming of the local tracking branch, you can specify it as follows:

<code bash>
git checkout -t -b dev remotes/origin/dev
</code>

If master (or main) changes while you’re making changes in a branch, you can merge them into the branch as follows:

<code bash>
git checkout main

git pull

git checkout <branch_name>

git merge main
</code>

To push the current branch to a remote repository, creating a new branch on the remote:

<code bash>
git push origin <remote_branch_name>
</code>

If you are currently in a local branch, and you know the branch also exists in a remote repository, but a git pull fails, you may need to link the local branch to the server branch. For example, if the local and server branches are both named “dev”, you’d link them as follows:

<code bash>
git branch --set-upstream-to=origin/dev dev
</code>

To switch back to the master branch:

<code bash>
git checkout master
</code>

Delete a local branch:

<code bash>
git branch -D <branch-name>
</code>

Delete a remote branch:

<code bash>
git branch -r -D <branch-name>
</code>

===== Security =====

To bypass SSL verification, add this entry to .bashrc:

<code>
alias git='git -c http.sslVerify=false'
</code>

<WRAP center round important 60%>
Only use this if you //know// the network you’re using can be trusted. This setting leaves you open to man-in-the-middle attacks.
</WRAP>

===== Git Setup For Specific Hosting Sites =====

==== Git Setup for Bitbucket ====

Set up your local directory:

<code bash>
mkdir /path/to/your/project
 
cd /path/to/your/project
 
git init
 
git remote add origin https://bitbucketid@bitbucket.org/bitbucketid/bitbucketproject.git
</code>

Create your first file, commit, and push:

<code bash>
echo "Your Name" >> contributors.txt
 
git add contributors.txt
 
git commit -m 'Initial commit with contributors'
 
git push -u origin master
</code>

==== Git Setup for GitHub (new) ====

<code bash>
mkdir -p ~/<projectname>
 
cd $_
 
echo "# <projectname>" >> README.md
 
git init
 
git add README.md
 
git commit -m "first commit"
 
git remote add origin https://github.com/<username>/<projectname>.git
 
git push -u origin master
</code>

==== Git Setup for GitHub (existing repository) ====

<code bash>
git remote add origin https://github.com/<username>/<projectname>.git
 
git push -u origin master
</code>

==== Automatic Authentication for GitHub, Bitbucket, and GitLab ====

Tired of being prompted for your userid and password every time you push local changes to your remote repository? Add the following to ~/.netrc.

For GitHub:

<code>
machine github.com
	login <username>
	password <password>
</code>

For Bitbucket:

<code>
machine bitbucket.org
	login <username>
	password <password>
</code>

For GitLab:

<code>
machine gitlab.com
	login <username>
	password <password>
</code>

(You can have all entries in the same file, if needed.)

===== More Git Tutorials and Reference =====

If you need more details, here are some comprehensive Git tutorials and references.

[[http://www.git-scm.com/docs/gittutorial|Official Tutorial]] – Hosted on the official Git site.

[[http://git-scm.com/book/en/v2|Pro Git]] – The entire book, hosted on the official Git site.

[[http://www.vogella.com/articles/Git/article.html|Vogella]] – A tutorial.

[[https://www.atlassian.com/git/tutorials/|Atlassian Tutorials]] – A series of tutorials hosted on the Atlassian site. (These guys also host Bitbucket.)