Version control systems are programs or software to manage the source code of computer programs. Most of the open source projects are now hosted on github. So learning about git and github is very much necessary to learning and start contributing to the open source projects. In this presentation I hope to get the audience introduced to the basics of version control systems and learn the basics of git. http://shdlr.com/conferences/talk/20332

1. 03/18/16 NOS Conf 2016
Version control system with git
and (github) as an example
Gaurav Garg
@gaurav_garg_
ggarg@redhat.com
freenode irc nic: ggarg

2. 03/18/16 NOS Conf 2016
Agenda

VCS – What is it ?

Why using a VCS is good idea

Git Basic including:
➢How to obtain and install Git
➢How to use it for basic/common operation
➢More information resource for Git

Q & A

3. 03/18/16 NOS Conf 2016
VCS What is it ?
• A way to keep track of changes to files or folders
• Keep record of changes why, what, when
• Non distributed system (subversion, CVS)
server has the master repo, all commit goes to the server
• Distributed (Git, mercurial)
server has the master repo, but you have copy of that repo
(clone) in your machine

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Getting Git
•Dependencies:
* on a system that has yum (such as fedora)
$ yum install curl-devel expat-devel gettext-devel
openssl-devel zlib-devel
* on a system that has apt-get (debian based system)
$ apt-get install libcurl4-gnutls-dev libexpat1-dev gettext
libz-dev libssl-dev

5. 03/18/16 NOS Conf 2016
Getting Git cont...
•Get the latest snapshot from git website:
http://git-scm.com/download
Then, compile and install:
$ tar -zxf git-1.7.2.2.tar.gz
$ cd git-1.7.2.2
$ make prefix=/usr/local all
$ sudo make prefix=/usr/local install

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Getting Git cont...
• Binary Installer:
If you want to directly install binary then:
 For Fedora:
$ yum install git
 For debina based distribution:
$ apt-get install git
 For mac
$ brew install git

7. 03/18/16 NOS Conf 2016
Git basic operation
•Checking the installation:
Check if Git is installed
$ git - -version
git version 1.9.3
If not then follow the installation steps that mentioned in previous slides.
• Setting user name and email to your git config:
$ git config --global user.name "Gaurav Kumar Garg"
$ git config --global user.email " ggarg@redhat.com"
Note: If you want to set it for specific repositery then cd to that repositery and
Remove “--global” option.
$ git config - -list command will verify user name and email address

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Git basic operation cont...
• Obtaining a repository:
Creating a repository (if it does not exist remotely)
$ git init (follow http://git-scm.com/docs/git-init for more information)
Or cloning a remote repository:
git clone ssh://[username@]git.gluster.org/glusterfs.git glusterfs
For eg: cloning a gluserfs repository:
git clone ssh://ggarg@git.gluster.org/glusterfs.git glusterfs
here glusterfs is optional, which will be the name of repository.
Inspecting a repo: $ vim .git/config

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Git basic operation cont...
• Inspecting repo:
$ git tag
will show you list of all tags (versioning of software)
$ git status
Difference b/w index file and current head commit
$ git log
Sow list of all commit with commit message
$ git log -1
Show top 1st commit
$ git log - -pretty=oneline
Show list of all commit in single line

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Git basic operation cont...
• Making edit and commiting
• Edit your file with your fav editor (vim/emac etc.) and save it.
• $ git diff
will show delta difference code of current master HEAD and current index
• $ git status
will show path of file as “Changes not staged for commit”
• $ git add (-A)
will show file as “Changes to be commited”
• $ git commit -s
write your commit message. Save and exit.
* file changed, * insertion, * deletion (-)
• Check your commit by $ git log

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Git basic operation cont...
• Recover your changes that you have added by
mistakes
$ git add <file name>
file <file name> that you have added by mistake
$ git status
$ git reset HEAD <filename>
$ git checkout - - <filename>

12. 03/18/16 NOS Conf 2016
Git basic operation cont...
• Best pratice is to make seperate branch
$ git branch <branch name>
or
$ git checkout -b <branch name>
$ git branch -D <branch name>
will delete branch <branch name>
$ git branch -m <branch name> <new name>
will rename branch <branch name > with <new name>

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Git basic operation cont...
• Git Stashing
Will allow you to save your changes without commiting them.
• $ git stash
save your change as a seperte stash@{*} branch with commit
message
• $ git stash list
will show you list of all stash with commit message
• $ git show <stash@{0}>
will show you what code difference contain this this stash@{0}
• $ git apply <stash@{0}>
will allow to apply change in current branch.

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Git basic operation cont...
• Git rebase
forward-port local commit to local upstream master
• $ git rebase master
* will update your local commit with master
• $ git rebase -i HEAD~3
* will pick up top 3 commit and it
* can be use for reword, edit, squash commit

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Git basic operation cont...
• Adding remote:
• $ git remote add <remote name> <remote_url>
Adding remote repo address in your local machine
user can add multiple remote repo address
• $ git remote -v
will show you list of all remote address with name
• $ git push <remote name> <branch name>
will push <branch name> change to remote address

16. 03/18/16 NOS Conf 2016
Git basic operation cont...
• Git tagging
• $ git tag
* will list out all the tags (calles as versioning of
software)
• $ git tag -a <tag name> -m “tag description”
* will give tag with tag name of tag version with
current branch HEAD
• $ git tag -d <tag name>
* Delete tag <tag name>

17. 03/18/16 NOS Conf 2016
More information resource for Git
• $ git - -help
for eg: git - -help <rebase>
will give your help regarding “git rebase”
• http://git-scm.com/docs/
contains resource of all git related command/operations.

18. 03/18/16 NOS Conf 2016
Thank you....

19. 03/18/16 NOS Conf 2016
Q/A