Git

Git is a version control system

Used for keeping track of changes to code

Install Git

Mac

$ brew install git

Windows

http://msysgit.github.io

Sample Project

Create a file in a directory

$ mkdir hello
$ cd hello
$ echo '# Hello' > README.md
$ ls
README.md
$ cat README.md
# Hello

Initialize a Git repository

$ git init
Initialized empty Git repository in /Users/pbarry/dev/hello/.git/

Note that the repository is stored in a hidden directory called .git

Status

Use git status to view the state of your working directory compared to your repository

$ git status
# On branch master
#
# Initial commit
#
# Untracked files:
#   (use "git add <file>..." to include in what will be committed)
#
#  README.md
nothing added to commit but untracked files present (use "git add" to track)

Add a file

$ git add README.md

That change is staged, but not commited

$ git status
# On branch master
#
# Initial commit
#
# Changes to be committed:
#   (use "git rm --cached <file>..." to unstage)
#
#  new file:   README.md
#

Commit changes

Use git commit

$ git commit -m 'First commit!'
[master (root-commit) b4d2429] First commit!
 1 file changed, 1 insertion(+)
 create mode 100644 README.md

Log

View your changes with git log

$ git log
commit b4d2429f0b1b77393824472feaf68a4cec3147d5
Author: Paul Barry <mail@paulbarry.com>
Date:   Thu Sep 19 12:02:04 2013 -0400

    First commit!

Make some changes

$ echo 'Goodbye' > README.md
$ git status
# On branch master
# Changes not staged for commit:
#   (use "git add <file>..." to update what will be committed)
#   (use "git checkout -- <file>..." to discard changes in working directory)
#
#  modified:   README.md
#
no changes added to commit (use "git add" and/or "git commit -a")

View diff

See what changed

$ git diff
diff --git a/README.md b/README.md
index fec5601..2b60207 100644
--- a/README.md
+++ b/README.md
@@ -1 +1 @@
-# Hello
+Goodbye

Add the changes

$ git add README.md
$ git status
# On branch master
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#  modified:   README.md
#

Use Atom for editing commit messages

$ git config --global core.editor 'atom -w'
$ git commit
[master 7e9d0c2] Made some changes
 1 file changed, 1 insertion(+), 1 deletion(-)

Working directory is now clean

$ git status
# On branch master
nothing to commit, working directory clean

View commits

$ git log
 commit 7e9d0c212c11965d9a4d1be391d8dc76441b595d
 Author: Paul Barry <mail@paulbarry.com>
 Date:   Thu Sep 19 14:20:56 2013 -0400

     Made some changes

 commit b4d2429f0b1b77393824472feaf68a4cec3147d5
 Author: Paul Barry <mail@paulbarry.com>
 Date:   Thu Sep 19 12:02:04 2013 -0400

     First commit!

Undoing changes

Use revert to undo changes

$ git revert 7e9d0c212c11965d9a4d1be391d8dc76441b595d
[master fe537d4] Revert "Made some changes"
 1 file changed, 1 insertion(+), 1 deletion(-)

A new commit that undid the changes was created

$ git log
commit fe537d47dbbe59653c130843ae0c5c0d65021fc9
Author: Paul Barry <mail@paulbarry.com>
Date:   Thu Sep 19 14:24:28 2013 -0400

    Revert "Made some changes"

    This reverts commit 7e9d0c212c11965d9a4d1be391d8dc76441b595d.

commit 7e9d0c212c11965d9a4d1be391d8dc76441b595d
Author: Paul Barry <mail@paulbarry.com>
Date:   Thu Sep 19 14:20:56 2013 -0400

    Made some changes
...

GitX

Graphical tool for using git - http://gitx.frim.nl

Github

A website that hosts git repositories