Intro to

katopod@csd.uoc.gr

Let me tell you a story

Started alone

Got company

Used and sticks

Did not work that well

Used

Conflicted copies

But then something wonderful happened

Found GIT

What is GIT?


Is GIT hard?

Will it take me a long time to learn?

What are we learning today?

Setup

Installing GIT


Project hosting


Terminology

Basic workflow


Let's create a repository!

Say hello


$ git config --global user.name "Alex Katopodis"
$ git config --global user.email "katopod@csd.uoc.gr"

Initialize

$ git init

creates .git dir, repository is in there

Check

$ git status

Shows info about modified, new, and deleted files

Not much to see yet

$ git status
On branch master

Initial commit

nothing to commit (create/copy files and use "git add" to track)

The repository is empty, let's add stuff

$ touch nyancat.js
$ git status
On branch master

Initial commit

Untracked files:
  (use "git add <file>..." to include in what will be committed)

  nyancat.js

nothing added to commit but untracked files present (use "git add" to track)

Add

$ git add <file>...

Add files to staging area

git add -A adds all new, modified, and deleted files from the working area 

$ git add nyancat.js
$ git status
On branch master

Initial commit

Changes to be committed:
  (use "git rm --cached <file>..." to unstage)

  new file:   nyancat.js

Commit

$ git commit

Records changes to repository, you have to provide a commit message

git commit -m "commit description"

will commit with the message you provide

$ git commit -m "nyan~"
[master (root-commit) b748793] nyan~
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 nyancat.js
$ git status
On branch master
nothing to commit, working directory clean

Log

$ git log

Shows commit history 

$ git log
commit b748793a7febd39f911e53a1ee0f555924f8d77c
Author: Alex Katopodis <akatopo@users.noreply.github.com>
Date:   Tue Dec 8 22:12:00 2015 +0200

    nyan~

.gitignore


Sample .gitignore

# Can ignore specific files
.DS_Store
# Use wildcards as well
*~
*.swp
# Can also ignore all directories
# and files in a directory.
tmp/**/*
More @ help.github.com

Let's add some more content

$ echo "console.log('meow!')" >> nyancat.js
$ 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:   nyancat.js

no changes added to commit (use "git add" and/or "git commit -a")

Changes

$ git diff

Shows changes between working directory and index

$ git diff HEAD

Shows changes between working directory and repository

$ git diff --cached

Shows changes between index and repository

$ git diff
diff --git a/nyancat.js b/nyancat.js
index e69de29..f842659 100644
--- a/nyancat.js
+++ b/nyancat.js
@@ -0,0 +1 @@
+console.log('meow!')
$ git add nyancat.js
$ git commit -m "meow"
[master b4ea710] meow
 1 file changed, 1 insertion(+)

Remove changes

$ git checkout -- <file>...

Removes changes from working directory

The -- separates options from other arguments

This will permanently remove your changes from the working directory

Remove changes pt. 2

$ git reset HEAD <file>...

Removes changes from index

Branching out

Create a new branch


Branch

$ git branch <branchname>

Creates branch

git branch

Lists branches

git branch -d <branchname>

Removes branch

Checkout

$ git checkout <branchname>

Switches to branch

$ git branch branch-nyao
$ git branch
  branch-nyao
* master
$ git checkout branch-nyao
Switched to branch 'branch-nyao'

Merge changes back


Merge

$ git merge <branchname>

Merges branch into current branch

$ echo "console.log('rawr!')" >> nyancat.js
$ git add nyancat.js && git commit -m 'rawr'
[branch-nyao 550fd06] rawr
 1 file changed, 1 insertion(+)
$ git checkout master
Switched to branch 'master'
$ git merge branch-nyao
Updating b4ea710..550fd06
Fast-forward
 nyancat.js | 1 +
 1 file changed, 1 insertion(+)

Remotes

Add remote

$ git remote add <remotename> <remotelocation>

Sets a new remote with name remotename

git remote -v

Shows a list of existing remotes

Push to remote

$ git push -u <remotename> <remotebranchname>

Pushes changes to remote with name remotename and branch remotebranchname

-u tracks the remote's branch 

$ git remote add origin git@github.com:akatopo/yummy-octo-turtle.git
$ git remote -v
origin  git@github.com:akatopo/yummy-octo-turtle.git (fetch)
origin  git@github.com:akatopo/yummy-octo-turtle.git (push)
$ git push -u origin master
Counting objects: 9, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (3/3), done.
Writing objects: 100% (9/9), 675 bytes | 0 bytes/s, done.
Total 9 (delta 1), reused 0 (delta 0)
To git@github.com:akatopo/yummy-octo-turtle.git
 * [new branch]      master -> master
Branch master set up to track remote branch master from origin.

Pull from remote

$ git pull

Pulls changes from the remote's branch we tracked earlier

$ git pull
remote: Counting objects: 3, done.
remote: Compressing objects: 100% (2/2), done.
remote: Total 3 (delta 0), reused 0 (delta 0), pack-reused 0
Unpacking objects: 100% (3/3), done.
From github.com:akatopo/yummy-octo-turtle
   550fd06..1c866cb  master     -> origin/master
Updating 550fd06..1c866cb
Fast-forward
 nyancat.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Clone repository

git clone <remotelocation> <dirname>

Downloads selected remote repository from <remotelocation> to <dirname> 

$ git clone git@github.com:akatopo/yummy-octo-turtle.git yummy-octo-turtle
Cloning into 'yummy-octo-turtle'...
remote: Counting objects: 12, done.
remote: Compressing objects: 100% (4/4), done.
remote: Total 12 (delta 1), reused 9 (delta 1), pack-reused 0
Receiving objects: 100% (12/12), done.
Resolving deltas: 100% (1/1), done.
Checking connectivity... done.
$ tree yummy-octo-turtle
yummy-octo-turtle
└── nyancat.js

0 directories, 1 file

Let's put this all together

Extras

Apps


Documentation


Clone this presentation


git.io/git-intro

Thank you