8/7/2019 git-12613901533412-phpapp02

1/58

Clickicontoaddpicture

Clickicontoaddpicture

Git

The fast version control system

Jeroen Rosenbergjeroen.rosenberg@gmail.co

m

8/7/2019 git-12613901533412-phpapp02

2/58

Table of contents

Short introduction to version control

Version control systems

Comparison with subversionDistributed version control

Git usage

Basic operations

Solving conflicts

Branching as a core concept

Tooling

Conclusion

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

3/58

Version control

Short introduction

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

4/58

Version control (1)

The management of changes todocuments, programs, and otherinformation stored as computer files

A system that maintains versions of filesat progressive stages of development.

Every file

Has a full history of changes

Can be restored to any version

A communication tool, like email, butwith code rather than humanconversation

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

5/58

Version control (2)

Benefits

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

6/58

Version control (2)

Benefits

Allows a team to share code

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

7/58

Version control (2)

Benefits

Allows a team to share code

Maintains separate production versionsof code that are always deployable

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

8/58

Version control (2)

Benefits

Allows a team to share code

Maintains separate production versionsof code that are always deployable

Allows simultaneous development ofdifferent features on the same codebase

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

9/58

Version control (2)

Benefits

Allows a team to share code

Maintains separate production versionsof code that are always deployable

Allows simultaneous development ofdifferent features on the same codebase

Keeps track of all old versions of files

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

10/58

Version control (2)

Benefits

Allows a team to share code

Maintains separate production versionsof code that are always deployable

Allows simultaneous development ofdifferent features on the same codebase

Keeps track of all old versions of files

Prevents work being overwritten

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

11/58

Glossary

Some commonly used terms explained before movingon

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

12/58

Key terms in versioncontrol

Branch a copy of a set of files underversion control which may be developedat different speeds or in different ways

Checkout to copy the latest version of(a file in) the repository to your workingcopy

Commit to copy (a file in) your workingcopy back into the repository as a newversion

Merge to combine multiple changesmade to different working copies of thesame files in the repository

Repository a (shared) database with

the complete revision history of all filesunder version controlGit - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

13/58

Version controlsystems

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

14/58

Click icon to add picture

Click icon to add picture

Click icon to add picture

Very limited and inflexible

Concurrent VersionsSystem (CVS)

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

15/58

Click icon to add picture

Click icon to add picture

Click icon to add picture

Very limited and inflexible

Concurrent VersionsSystem (CVS)

Fills most of the holes found inCVS, but added nothing to itsdevelopment model

Subversion (SVN)

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

16/58

Click icon to add picture

Click icon to add picture

Click icon to add picture

Very limited and inflexible

Click icon to add picture

Concurrent VersionsSystem (CVS)

Fills most of the holes found inCVS, but added nothing to itsdevelopment model

Subversion (SVN)

More feature rich andfunctional

Git

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

17/58

Comparison with SVN

Subversion Git

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

18/58

Comparison with SVN

Subversion

Centralized

Git

Distributed

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

19/58

Comparison with SVN

Subversion

Centralized

Branching can be a pain andis used sparingly

Git

Distributed

Branching is very easy and isa core concept

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

20/58

Comparison with SVN

Subversion

Centralized

Branching can be a pain andis used sparingly

Conflicts frequently occur andrenaming is not handled well

Git

Distributed

Branching is very easy and isa core concept

Conflicts occur less frequent,renaming is properly handled

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

21/58

Comparison with SVN

Subversion

Centralized

Branching can be a pain andis used sparingly

Conflicts frequently occur andrenaming is not handled well

Can be slow due to networklatency

Git

Distributed

Branching is very easy and isa core concept

Conflicts occur less frequent,renaming is properly handled

Very fast since less operationsinvolve network latency

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

22/58

Comparison with SVN

Subversion

Centralized

Branching can be a pain andis used sparingly

Conflicts frequently occur andrenaming is not handled well

Can be slow due to networklatency

Can consume quite some diskspace

Git

Distributed

Branching is very easy and isa core concept

Conflicts occur less frequent,renaming is properly handled

Very fast since less operationsinvolve network latency

Consumes 30 times less diskspace

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

23/58

Distributedversion control

The new generation of version control

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

24/58

Click icon to add picture

A basic, centralized version controlsystem

Users commitchanges to the central repository and a newversion is born to be checked out by other users

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

25/58

Click icon to add picture

A distributed version control system

Each user has a full local copy of the repository. Userscommitchanges and when they want to share it, the push itto the shared repository

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

26/58

Git usage

Basic operations

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

27/58

Tracking a project..

SVN Git

$ svn checkout url $ git clone url

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

28/58

8/7/2019 git-12613901533412-phpapp02

29/58

Tracking a project..

SVN Git

$ svn checkout url $ git clone url

My project is tiny - git is overkillWhy would I carry a Swiss knife when Ionly want to open cans?

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

30/58

8/7/2019 git-12613901533412-phpapp02

31/58

Tracking a project..

SVN Git

$ svn checkout url $ git clone url

$ svn update $ git pull

$ svn add file $ git add file$ svn rm file $ git rm file

$ svn mv file $ git mv file

$ svn commit $ git commit a

$ svn revert path $ git checkout path

Pretty straightforwarded, huh?

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

32/58

Advanced committing

SVN Git

$ svn mv file $ git mv file

$ svn commit $ git commit a$ svn revert path $ git checkout path

What if you screw up?#re-edit the metadata and update

the tree$ git commit --amend

or

# toss your latest commit away

without changing the working tree$ git reset HEAD^Git - the fast version control

s stem

8/7/2019 git-12613901533412-phpapp02

33/58

Solving conflicts

Instant merging

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

34/58

Closer look at pulling..

SVN Git

$ svn checkout url $ git clone url

$ svn update $ git pull

$ svn add file $ git add file

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

35/58

Auto-merging..

SVN Git

$ svn checkout url $ git clone url

$ svn update $ git pull

$ svn add file $ git add file

What actually happens

# Fetch latest changes from origin$ git fetch

# Merge fetched changes intocurrent branch$ git merge refs/heads/master

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

36/58

Auto-merging..

SVN Git

$ svn checkout url $ git clone url

$ svn update $ git pull

$ svn add file $ git add file

What actually happens

Recursive merge strategy create amerged reference tree of commonancestors for three-way merge

fewer merge conflicts can detect and handle renames

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

37/58

Resolving conflicts..

SVN Git

$ svn checkout url $ git clone url

$ svn update $ git pull

$ svn add file $ git add file

Suppose Jeff and Dan both madechanges to the same line in file

CONFLICT (content): Merge conflict in fileAutomatic merge failed; fix conflicts andthen commit the result.

Uh oh. now what?

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

38/58

Resolving conflicts..

SVN Git

$ svn checkout url $ git clone url

$ svn update $ git pull

$ svn add file $ git add file

Well, just merge manually

# run your favourite file mergeapplication$ git mergetool t opendiff

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

39/58

Git - the fast version controls stem

source: http://gitguru.com

8/7/2019 git-12613901533412-phpapp02

40/58

Resolving conflicts..

SVN Git

$ svn checkout url $ git clone url

$ svn update $ git pull

$ svn add file $ git add file

and commit!

# commit to resolve the conflict$ git commit

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

41/58

Branching

A core concept

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

42/58

Creating a branch..

SVN Git

$ svn copyurl_of_trunkurl_of_branch

$ svn switchurl_of_branch

$ git branchname_of_branch

$ git checkoutname_of_branch

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

43/58

Creating a branch..

SVN Git

$ svn copyurl_of_trunkurl_of_branch

$ svn switchurl_of_branch

$ git branchname_of_branch

$ git checkoutname_of_branch

Or create and switch to a branchbased on another branch

$ git checkout b new_branchother_branch

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

44/58

Click icon to add picture

Some common scenarios

Git - the fast version controls stem

Why would I require branching?

8/7/2019 git-12613901533412-phpapp02

45/58

Scenario 1 Interrupted workflow

Youre finished with part 1 of a new feature butyou cant continue with part 2 before part 1 is

released and tested

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

46/58

Scenario 1 Interrupted workflow

Youre finished with part 1 of a new feature butyou cant continue with part 2 before part 1 is

released and tested

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

47/58

Scenario 2 Quick fixes

While youre busy implementing some featuresuddenly youre being told to drop everything and

fix a newly discovered bug

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

48/58

Scenario 2 Quick fixes

While youre busy implementing some featuresuddenly youre being told to drop everything and

fix a newly discovered bug

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

49/58

Git usageoverview

Just to summarize

Git - the fast version controls stem

Git command sequence

8/7/2019 git-12613901533412-phpapp02

50/58

Git command sequence

Source: http://git.or.cz

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

51/58

Tooling

Stuck at Ye Olde Terminal? Not necessarily

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

52/58

Git UI front-ends

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

53/58

Click icon to add picture

Click icon to add picture

Click icon to add picture

OpenInGitGui

Git - the fast version controls stem

Finder extension

8/7/2019 git-12613901533412-phpapp02

54/58

Click icon to add picture

Click icon to add picture

Click icon to add picture

OpenInGitGui

Git - the fast version controls stem

Finder extension

TortoiseGit

Git Extensions

Windows Explorerextensions

8/7/2019 git-12613901533412-phpapp02

55/58

Click icon to add picture

Click icon to add picture

Click icon to add picture

OpenInGitGui

Git - the fast version controls stem

Finder extension

TortoiseGit

Git Extensions

Windows Explorerextensions

JGit / EGit

Eclipse integration

8/7/2019 git-12613901533412-phpapp02

56/58

Conclusion

Why switch to Git?

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

57/58

Reasons to switch to Git

Endless, easy, non-file-system-based,local branches

Enhanced merging strategy

Performance

Advanced features enable betterworkflow

Stashing temporary work

Collaboration before public commits

Git - the fast version controls stem

8/7/2019 git-12613901533412-phpapp02

58/58

Closing and Q&A

References

Git: http://git-scm.com/download

Git Docs: http://git-scm.com/documentation

GitX: http://gitx.frim.nl/

TortoiseGit: http://code.google.com/p/tortoisegit/

Git Extensions:http://sourceforge.net/projects/gitextensions/

JGit / EGit: http://www.eclipse.org/egit/

http://git-scm.com/downloadhttp://git-scm.com/documentationhttp://code.google.com/p/tortoisegit/http://sourceforge.net/projects/gitextensions/http://www.eclipse.org/egit/http://www.eclipse.org/egit/http://www.eclipse.org/egit/http://sourceforge.net/projects/gitextensions/http://code.google.com/p/tortoisegit/http://git-scm.com/documentationhttp://git-scm.com/download