Git.

Git is an SCM system.

Fast
Efficient
Easy to use
Distributed

Not centralized like many other SCM systems - most operations happen locally

Install

yum or apt-get install git

Others (YMMV):
http://git-scm.com/book/en/Getting-Started-Installing-Git

Tell it who you are

```
git config --global user.name "Mr X"
```

git config --global user.email me@home.com

Make a repository.

```
cd my_cool_project
```
```
git init
```

makes it a git repo - creates .git

Some basic commands

Check status of repo: git status

Track a file: git add myfile

Commit changes: git commit

See history: git log

git add can take a file or a subdirectory

git add <file>

Add a file to be 'tracked'
'Stage' changes to a tracked file

```
git add .
```

To stage changes means to add them to the index or cache or 'staging area'

git commit

Record a set of changes

```
git commit -m "Initial commit"
```
```
git commit --amend
```

A commit is a record of changes to a repository

tracked/untracked files - states

modified
staged
committed

untracked
ignored

See what state a file is in using 'git status' - won't show ignored

Making changes

Edit a file as normal, then:

```
git diff
```

```
git add <file>
```

```
git diff --cached
```

```
git commit
```

'--cached' shows diff between HEAD and index, without it, we see modified files

Le commit

A commit is an object in git that has a record of tracked files and a message describing the changes made at that point. See git log

SHA-1 hash (representing index at commit time)
Committer details
Comment
Date

Changing anything will lead to different hash; different commit

Commit message guidelines

Capitalized, short (50 chars or less) summary

More detailed explanatory text, if necessary. Wrap it to about 72
characters or so. Leave blank line between summary (first line) & body.

Body can be many detailed paragraphs long. Bullet points are also
acceptable, using either - or *. Also, don't end summary with a
period.

Part two

Working with branches.

One of the Git's killer features. Easy and efficient.

Some terms & commands

master - default branch.
HEAD - pointer to the tip of current branch

List local branches: git branch
List remote branches: git branch -r

Why branch

Create disposable 'topic' branches for focused units of work
Create long-term branches for various workflows
Have different branches to track different remote repositories

Bad ideas; Fedora package collection; github/gitorious

Create a branch and 'check it out'

```
git branch mynewbranch myexistingbranch
```
```
git checkout mynewbranch
```

```
git checkout -b mynewbranch
```

Work just like before, only changes here won't be reflected in existing branch

Merging branches

Add changes from one branch to another branch where they haven't been applied yet.

A few types. Most common:
fast-forward - move tip of current branch forward
true merge - results in an extra commit (2 parents)

Examples

ff: branch, add new commit to one, merge into the other
true: branch, add different commits to both sides, merge one into other

Merge Conflicts

Merge conflicts usually happen when 2 branches are being merged which have overlapping changes

Options when conflicts happen

```
git merge --abort
```
- Go back to before you called merge

```
git mergetool
```
- graphical tool to try to help you solve differences

Solve conflicts by hand, git add each resolved file, then git commit

'Rebase'

A rebase is like a merge, except it tries to keep things cleaner so the history is more linear.

'Rebase'

```
git rebase <branch>
```
Put new commits on current branch on top of new commits on <branch>

Conflicts/problems during a rebase

```
				git merge --abort
			
```
```
git rebase --abort
```

THIS IS IMPORTANT

Don't use rebase if you've already pushed commits that it will change.

Part three

Working with remotes.

Git on the internet.

Some free Git repository hosting

gitorious.org
repo.or.cz
github.com
bitbucket.com
sourceforge.net
code.google.com

Putting stuff into a remote repo: pushing

git remote add <remote-nick> <remote-ssh-address>

git remote add origin git@github.com:grdryn/example.git

```
git push -u origin master
```

Getting stuff from a remote repo

In an existing repository (that has a remote):
```
git fetch
```
```
git pull
```
```
git pull origin master
```

Grab an entire repository that you don't have:
```
git clone <repo-url>
```

Advantages of remote repositories

Collaborate with others
Backup your project
A place for people to download your project
Find cool projects by others

Other useful commands to try

```
git help
```
```
git help <other-git-command>
```

```
git reflog
```

```
git rev-parse
```
```
git bisect
```
```
git blame
```
```
git stash
```
```
git reset
```

Places to get help/tips

http://git-scm.com
http://www.ndpsoftware.com/git-cheatsheet.html
https://help.github.com/
http://gitguys.com
http://coderwall.com/n/git
http://stackoverflow.com/questions/tagged/git

Git.

Git is an SCM system.

Install

Tell it who you are

Make a repository.

Some basic commands

git add <file>

git commit

tracked/untracked files - states

Making changes

Le commit

Commit message guidelines

Part two

Some terms & commands

Why branch

Create a branch and 'check it out'

Merging branches

Examples

Merge Conflicts

Options when conflicts happen

'Rebase'

'Rebase'

Conflicts/problems during a rebase

THIS IS IMPORTANT

Part three

Some free Git repository hosting

Putting stuff into a remote repo: pushing

Getting stuff from a remote repo

Advantages of remote repositories

Other useful commands to try

Places to get help/tips

End!