Git Slides

Intro Git Example Advices

Using Git

Matthieu Moy

Matthieu.Moy@imag.fr

2009-2010

Matthieu Moy (Matthieu.Moy@imag.fr) Git 2009-2010 < 1 / 19 >

Outline

1 Revision Control System

2 Git: Basic Principles

3 An Example Using Git

4 Advices Using Git

Backups: The Old Good TimeBasic problems:

I “Oh, my disk crashed.” / “Someone has stolen my laptop!”I “@#%!!, I’ve just deleted this important file!”I “Oops, I introduced a bug a long time ago in my code, how can I

see how it was before?”

Historical solutions:

I Replicate:$ cp -r ~/project/ ~/backup/

I Keep history:$ cp -r ~/project/ ~/backup/project-2006-10-4

I Keep a description of history:$ echo "Description of current state" > \

~/backup/project-2006-10-4/README.txt

see how it was before?”Historical solutions:

Collaborative Development: The Old Good TimeBasic problems: Several persons working on the same set of files

1 “Hey, you’ve modified the same file as me, how do we merge?”,2 “Your modifications are broken, your code doesn’t even compile. Fix

your changes before sending it to me!”,3 “Your bug fix here seems interesting, but I don’t want your other

changes”.

Historical solutions:

I Never two person work at the same time. When one person stopsworking, (s)he sends his/her work to the others.⇒ Doesn’t scale up! Unsafe.

I People work on the same directory (same machine, NFS, . . . )⇒ Painful because of (2) above.

I People lock the file when working on it.⇒ Hardly scales up!

I People work trying to avoid conflicts, and merge later.

changes”.Historical solutions:

Merging: Problem and Solution

My version

#include <stdio.h>

int main () {printf("Hello");

return EXIT_SUCCESS;}

Your version

#include <stdio.h>

int main () {printf("Hello!\n");

return 0;}

Common ancestor

#include <stdio.h>

return 0;}

Tools like diff3 or diff + patch can solve this

Merging relies on history!

Collaborative development linked to backups

My version

#include <stdio.h>

Your version

#include <stdio.h>

return 0;}

Common ancestor

#include <stdio.h>

return 0;}

My version

#include <stdio.h>

Your version

#include <stdio.h>

return 0;}

Common ancestor

#include <stdio.h>

return 0;}

My version

#include <stdio.h>

Your version

#include <stdio.h>

return 0;}

Common ancestor

#include <stdio.h>

return 0;}

Merging

Space of possible revisions

(arbitrarily represented in 2D)

Merging

YoursAncestor

Merging

YoursAncestor

Merged revision

Revision Control System: Basic Idea

Keep track of history:I User makes modification and use commit to keep a snapshot of

the current state,I Meta-data (user’s name, date, descriptive message,. . . ) recorded

together with the state of the project.Use it for merging/collaborative development.

I Each user works on its own copy,I User explicitly “takes” modifications from others when (s)he wants.

(Efficient storage/compression)

Revision Control System: Basic Idea

Keep track of history:I User makes modification and use commit to keep a snapshot of

the current state,I Meta-data (user’s name, date, descriptive message,. . . ) recorded

together with the state of the project.Use it for merging/collaborative development.

I Each user works on its own copy,I User explicitly “takes” modifications from others when (s)he wants.

(Efficient storage/compression)

Outline

4 Advices Using Git

Git: Basic concepts

Each working directory contains:I The files you work on (as usual)I The history, or “repository” (in the directory .git/)

Basic operations:I git clone: get a copy of an existing repositoryI git commit: create a new revision in a repositoryI git pull: get revisions from a repositoryI git push: send revisions to a repository

For us:I Each team has a shared repository, already initialized

Outline

4 Advices Using Git

Starting the project with Git

Shared Repository

Student 1

CloneA

Shared Repository

Student 1

CloneA

Commit

Shared Repository

Student 1

CloneA

Commit

Student 2

Shared Repository

Student 1

CloneA

Commit

Student 2

CommitE

Shared Repository

Student 1

CloneA

Commit

Student 2

CommitE

Shared Repository

Student 1

CloneA

Commit

Student 2

CommitE

Push DPull

Shared Repository

Student 1

CloneA

Commit

Student 2

CommitE

Push DPull

Commit

Shared Repository

Student 1

CloneA

Commit

Student 2

CommitE

Push DPull

Commit

Starting the project with Git: in Practice

Alice$ git clone ssh://ldb42@telesun.imag.fr/~/git ipsimInitialized empty Git repository in /perms/Alice/ipsim/.git/remote: Counting objects: 960, done.remote: Compressing objects: 100% (555/555), done.remote: Total 960 (delta 341), reused 949 (delta 330)Receiving objects: 100% (960/960), 1.51 MiB, done.Resolving deltas: 100% (341/341), done.

Alice$ git clone ssh://ldb42@telesun.imag.fr/~/git ipsimAlice$ cd ipsim/sandboxAlice$ vi hello.c

Alice$ git clone ssh://ldb42@telesun.imag.fr/~/git ipsimAlice$ cd ipsim/sandboxAlice$ vi hello.cAlice$ git status# On branch master# Changed but not updated:# (use "git add <file>..." to update what will be committed)# (use "git checkout -- <file>..." to discard changes in working directory)## modified: hello.c#

Alice$ git clone ssh://ldb42@telesun.imag.fr/~/git ipsimAlice$ cd ipsim/sandboxAlice$ vi hello.cAlice$ git statusAlice$ git diff HEAD--- a/projet/sandbox/hello.c+++ b/projet/sandbox/hello.c@@ -1,5 +1,5 @@/* Chacun ajoute son nom ici */-/* Auteurs : ... et ... */+/* Auteurs : Alice et ... */

#include <stdio.h>

Alice$ git clone ssh://ldb42@telesun.imag.fr/~/git ipsimAlice$ cd ipsim/sandboxAlice$ vi hello.cAlice$ git statusAlice$ git diff HEADAlice$ git commit -a[master d943af5] Added my name.1 files changed, 1 insertions(+), 1 deletions(-)

Alice$ git clone ssh://ldb42@telesun.imag.fr/~/git ipsimAlice$ cd ipsim/sandboxAlice$ vi hello.cAlice$ git statusAlice$ git diff HEADAlice$ git commit -aAlice$ git logcommit d943af53ec13b43eac31d4cca3b11f51746a90ccAuthor: Alice <Alice@ensimag.imag.fr>

Added my name.

commit 96e1dead6dc0f8e23308726d22bbf42d0e99352fAuthor: Equipe ldb42 <ldb42@telesun.imag.fr>

Personalisation du dépôt pour ldb42

Shared Repository

Student 1

CloneA

Commit

Bob$ git clone ssh://ldb42@telesun.imag.fr/~/git ipsimInitialized empty Git repository in /perms/Bob/ipsim/.git/remote: Counting objects: 960, done.remote: Compressing objects: 100% (555/555), done.remote: Total 960 (delta 341), reused 949 (delta 330)Receiving objects: 100% (960/960), 1.51 MiB, done.Resolving deltas: 100% (341/341), done.

Bob$ git clone ssh://ldb42@telesun.imag.fr/~/git ipsimBob$ cd ipsim/sandboxBob$ vi hello.c

Bob$ git clone ssh://ldb42@telesun.imag.fr/~/git ipsimBob$ cd ipsim/sandboxBob$ vi hello.cBob$ git commit -a[master ae00028] Removed a piece of code.1 files changed, 0 insertions(+), 10 deletions(-)

Bob$ git clone ssh://ldb42@telesun.imag.fr/~/git ipsimBob$ cd ipsim/sandboxBob$ vi hello.cBob$ git commit -aBob$ git logcommit ae000285167885b286401ea3eb3379a7a3946260Author: Bob <Bob@telesun.imag.fr>Date: Thu Nov 19 16:52:53 2009 +0100

Removed a piece of code.

commit 96e1dead6dc0f8e23308726d22bbf42d0e99352fAuthor: Equipe ldb42 <ldb42@telesun.imag.fr>Date: Thu Nov 19 16:30:54 2009 +0100

Personalisation du dépôt pour ldb42

Shared Repository

Student 1

CloneA

Commit

Student 2

CommitE

Bob$ git pushCounting objects: 9, done.Delta compression using up to 16 threads.Compressing objects: 100% (4/4), done.Writing objects: 100% (5/5), 432 bytes, done.Total 5 (delta 2), reused 0 (delta 0)To ssh://ldb42@telesun.imag.fr/~/git

96e1dea..ae00028 master -> master

Bob$ git push

# back to AliceAlice$ git pushTo ssh://ldb42@telesun.imag.fr/~/git! [rejected] master -> master (non-fast forward)error: failed to push some refs to ’ssh://ldb42@telesun.imag.fr/~/git’To prevent you from losing history, non-fast-forward updates were rejectedMerge the remote changes before pushing again. See the ’non-fast forward’section of ’git push --help’ for details.

Bob$ git push

# back to AliceAlice$ git pushAlice$ git pullUnpacking objects: 100% (5/5), done.From ssh://telesun.imag.fr/~/git

96e1dea..ae00028 master -> origin/masterAuto-merging sandbox/hello.cMerge made by recursive.sandbox/hello.c | 10 -------1 files changed, 0 insertions(+), 10 deletions(-)

Bob$ git push

# back to AliceAlice$ git pushAlice$ git pullAlice$ vi hello.cAlice$ git commit -a[master ee9f864] Test1 files changed, 1 insertions(+), 0 deletions(-)

Bob$ git push

# back to AliceAlice$ git pushAlice$ git pullAlice$ vi hello.cAlice$ git commit -aAlice$ git log --graph --oneline

* ee9f864 Test

* 830a084 Merge branch ’master’ of ...|\| * ae00028 Removed a piece of code.

* | d943af5 Added my name.|/

* 96e1dea Personalisation du dépôt pour ldb42

Bob$ git push

# back to AliceAlice$ git pushAlice$ git pullAlice$ vi hello.cAlice$ git commit -aAlice$ git log --graph --onelineAlice$ git pushCounting objects: 23, done.Delta compression using up to 16 threads.Compressing objects: 100% (12/12), done.Writing objects: 100% (15/15), 1.20 KiB, done.Total 15 (delta 6), reused 0 (delta 0)To ssh://ldb42@telesun.imag.fr/~/git

ae00028..ee9f864 master -> master

Shared Repository

Student 1

CloneA

Commit

Student 2

CommitE

Push DPull

Commit

Outline

4 Advices Using Git

Advices Using Git

Never exchange files outside Git’s control (email, scp, usb key),except if you really know what you’re doing;

Always use git commit with -a;Make a git push after each git commit -a, except to keepyour modifications private. It can be necessary to make a gitpull before a git push if new revisions are available in theshared archive;Do git pull regularly, to remain synchronized with yourteammates. You need to make a git commit -a before you canmake a git pull (this is to avoid mixing manual changes withmerges).

Advices Using Git

Never exchange files outside Git’s control (email, scp, usb key),except if you really know what you’re doing;Always use git commit with -a;Make a git push after each git commit -a, except to keepyour modifications private. It can be necessary to make a gitpull before a git push if new revisions are available in theshared archive;Do git pull regularly, to remain synchronized with yourteammates. You need to make a git commit -a before you canmake a git pull (this is to avoid mixing manual changes withmerges).

Git Slides

Documents

Transcript of Git Slides

Git Intermediate Workshop slides v1.3

Lab 5: Dr. Tig’s Git Tutorial - Dalhousie Universityvlado/csci2132/slides/sd-lab05-slides.pdfSoftware Development Lab 5: Dr. Tig’s Git Tutorial Instructor: ... Lots of open source

Git & Git Workflows

Matthieu Moy - chamilo.grenoble-inp.frchamilo.grenoble-inp.fr/.../Slides/git-slides.pdf · IntroGitAdvicesSéance Machine Using Git Matthieu Moy Matthieu.Moy@imag.fr 2018-2019 Matthieu

git-workshop-slides - Kristen KwongSlides: kristen.dev/blog/git. Title: git-workshop-slides Created Date: 3/4/2020 9:54:04 PM ...

Git it Together: The Slides - University of Kansas · PDF fileGit it Together: The Slides Paul E. Johnson1 2 1Department of Political Science ... Git for Windows includes a Windows

Github Git Training Slides

Git - a fast distributed revision control systemneuralensemble.org/media/slides/CodeJam2_Mueller_Git.pdf · Git Features distributed development model gives each developer a local

git (advanced) in 5 slides

Intelligent Robotics (FRI) CS 378: Autonomous › ~todd › cs378 › slides › Week11a.pdf · Clone an existing repository git clone url Add a new file to be tracked git add filename

GIT-Equivalence and Semi-Stable Subcategories of Quiver …homepage.math.uiowa.edu/~fbleher/CGMRT2016/Slides/... · 2016. 11. 29. · GIT-Equivalence and Semi-Stable Subcategories

understanding Git - Massachusetts Institute Ofweb.mit.edu/cluedumps/slides/understanding-git-2008.pdf · git rm file Delete file from the index and the working tree. ... 1 files changed,

Git for Teams of One or More - emmajane.github.ioemmajane.github.io/gitforteams/handouts/slides-gitforteams... · Git for Teams of One or More Emma Jane Westby Twitter: emmajanehw

Git,Gerrit,and% Jirafor Automo1ve%Grade%Linux%events17.linuxfoundation.org/sites/events/files/slides/Git Gerrit and Jira for AGL... · Open’Tasks’and’Bugs’ Slide8’ Issue

2012 GIT Sinhala @ apepanthiya GIT Sinhala @ apepanthiya.lk.pdf2012 GIT Sinhala @ apepanthiya.lk Subject: G.C.E A/L GIT Past Papers Keywords: git, al git, git papers, git past papers,

Physiology, Lecture 8, GIT 2 (Stomach) (Slides)

GIT - Community slides lec 1.ppt

2012 GIT English - Ape Panthiya GIT English... · 2012 GIT English @ apepanthiya.lk Subject: G.C.E A/L GIT Past Papers Keywords: git, al git, git papers, git past papers, git exam,

Johan Herland €¦ · The Git Parable Git - simple & powerful git init git add … git commit … git branch … git checkout … git tag … git diff …

Git-deliver Ignite slides for DevOps Days Paris 2015