Technical: Installing and Using GIT Command Line Interface on CentOS
Background
Now that my primary box is this CentOS Linux box, I need to make sure that I can share a bit on it.
With a web browser, I am able to post to wordpress.
And, I probably can look for a web interface to get to github, as well. But, I really need to re-familiarize with Bash and command line stuff.
And, so I will stay away from nice, pretty GUI for now. And, go shell.
Installation
On CentOS, we can install via the yum.
sudo yum install git-core
Yum install is easy as it takes care of installing all the dependant files.
Customize
Set User name
git config --global user.name "Daniel Adeniji"
Set email address
git config --global user.email "Daniel_Adeniji@nobody.com"
Create a repository
Connect to your github online account, and create a new repository
Identify local folder on host
On your Linux\Cent OS host, identify or create local folder that will serve as your working folder.
In our case, we will use /home/dadeniji/development/apache.org/tomcat/MSAdventureWorksDWDB.Public
Change Working Directory
Make identified folder your working directory
Launch Unix terminal and change working folder to identified folder.
Syntax:
cd <working-folder>
Sample
cd /home/dadeniji/development/apache.org/tomcat/MSAdventureWorksDWDB.Public
Clone Git Repository
Clone Git Repository
Syntax:
git clone git@github.com:<user-name>/<file>.git
Sample:
git clone git@github.com:DanielAdeniji/JavaJSPJSTLMSSQL.git
Output:
Here is the output we got back…
[dadeniji@adelia MSAdventureWorksDWDB.Public]$ ssh -vT git@github.com
OpenSSH_6.6, OpenSSL 1.0.1e-fips 11 Feb 2013
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Connecting to github.com [192.30.252.130] port 22.
debug1: Connection established.
debug1: Host 'github.com' is known and matches the RSA host key.
debug1: Found key in /home/dadeniji/.ssh/known_hosts:2
debug1: No more authentication methods to try.
Permission denied (publickey).
[dadeniji@adelia MSAdventureWorksDWDB.Public]$
Set up SSH Keys
We know that we have yet to set up SSH keys on this box. And, unfortunately I do not recollect where I placed previously used ones.
So let us go re-create SSH (Private & Public) keys.
Thankfully, GitHub has very good documentation on doing so:
https://help.github.com/articles/generating-ssh-keys
SSH Key Folder Location
SSH Keys are kept in /home/<username>/.ssh and in our case it is /home/dadeniji/.ssh.
In Linux by convention folders whose name starts with . are hidden files. And, so the folder might not show up.
Here is a default listing Folder Listing:
Enhanced Folder Listing:
On CentOS, to view hidden files, please click on the menu items “View”/ “Show Hidden Views” or use the keystrokes (CTRL-H).
Here is the “Show Hidden Views” picture:
Check for SSH Key
Command:
cd ~/.ssh
ls -al
Output:
Generate SSH Key
Command:
ssh-keygen -t rsa -C "dadeniji@ephraimtech.com"
Output:
Add Key to SSH Agent
Command:
ssh-add ~/.ssh/id_rsa
Output:
Review SSH Keys
Let us re-issue ls, and see whether we now have our keys.
Command:
cd ~/.ssh
ls -al
Output:
Add SSH Keys to Git-Hub
- Access Github
- In the top bar (https://github.com)
Click on the wrench button 
.- The “Account Settings” ( https://github.com/settings/profile ) will show up
- The “Account Settings” screen looks like this:
- Click on “SSH Keys”
- SSH Keys:Listing for SSH Keys.
- Click on the “Add SSH key”
- Post entering SSH Key
![AddSSHKey [after]](https://danieladeniji.files.wordpress.com/2014/04/addsshkey-after.png?w=700)
- Confirm password to continue — Enter password
- Here is the the listing of our “SSH Keys”
We can see that the new key’s status is listed as “Added just now — Never used“.
SSH Key – Test
Command:
ssh -T git@github.com
Output:
Output – Textual:
[dadeniji@adelia ~]$ ssh -T git@github.com
Warning: Permanently added the RSA host key for IP address '192.30.252.129' to the list of known hosts.
Hi DanielAdeniji! You've successfully authenticated, but GitHub does not provide shell access.
[dadeniji@adelia ~]$
Output – Image:
Clone Git Repository (Attempt #2)
Clone Git Repository
Syntax:
cd <home-directory>
git clone git@github.com:<user-name>/<file>.git
Sample:
cd /home/dadeniji/development/apache.org/tomcat/MSAdventureWorksDWDB.Public
git clone git@github.com:DanielAdeniji/JavaJSPJSTLMSSQL.git
Output:
Here is the output we got back…
Textual:
Initialized empty Git repository in /home/dadeniji/development/apache.org/tomcat/MSAdventureWorksDWDB.Public/JavaJSPJSTLMSSQL/.git/
warning: You appear to have cloned an empty repository.
Image:
Git Repository – Add
Add Files
Syntax:
cd <home-directory>
git add <files>
Sample:
git add '*.jsp'
Output:
Textual:
fatal: Not a git repository (or any of the parent directories): .git
Image:
Remediate
Googling on the error message tells me that I really needed to have indicated the folder that I wanted to use as my Git current folder.
As we did not indicate otherwise, a new folder is created underneath the current folder bearing:
In the screen above the name of the folder is JavaJSPJSTLMSSQL.
Move Git Local Repository
Move Git Local Repository
Syntax:
cd <home-directory>
mv <local-folder>/.git .
rm -rf <local-folder>
Sample:
cd /home/dadeniji/development/apache.org/tomcat/MSAdventureWorksDWDB.Public
move JavaJSPJSTLMSSQL/.git .
rm -rf JavaJSPJSTLMSSQL
Check Git Local Repository
Syntax:
git status --short
Sample:
git status --short
Output:
Reset Git Local Repository – Reset
Syntax:
git reset --hard
Sample:
git reset --hard
Output:
Textual:
fatal: Failed to resolve 'HEAD' as a valid ref.
Image:
We will ignore this error for now.
Git Repository – Add
Add Files
Syntax:
cd <home-directory>
git add <files>
Sample:
git add 'README.md'
git add '*.jsp'
git add '*.html'
git add 'META-INF/context.xml'
git add 'WEB-INF/*'
Git Repository – Create ignore file (.gitignore)
Add Files
Syntax:
touch .gitignore
Sample:
touch .gitignore
If there are files that we do not want shipped-off, we will list them in the .gitignore file.
Mask Private Data
We will like to share source code, but keep certain private data hidden. We will use sed for that.
Sample:
Git – Review File Status
Review Git Status in terms of what files are on.
Syntax:
git status
Sample:
git status
Output:
Git – Commit Changes – Locally
Commit Git Changes locally.
Syntax:
git commit -m <comment>
Sample:
git commit -a -m "initial batch"
Output:
Git – Commit Changes – Remotely
Commit Git Changes remotely.
Syntax:
git push -u origin master
Sample:
git push -u origin master
Output:
Git – Review Github
Let us quickly review Github and make sure that our files are there.
Our URL is https://github.com/DanielAdeniji/JavaJSPJSTLMSSQL.
Git – Review Log
We use “git log” to review our change logs.
Syntax:
git log
Sample:
git log
Output:
Listening to
Dave Loggins – Pieces of April
https://www.youtube.com/watch?v=gAlaYEmS0oY
References
References – Git – Tutorial
References – Git – SSH Key Management
References – Git – Q/A
References – Git – SSH Key – QA
References – SSH Key – Management
- Git Tutorial starting with git using 10 commands
![AddSSHKey [after]](https://danieladeniji.files.wordpress.com/2014/04/addsshkey-after.png)
