git.md

Version Control System - GIT

Basic entities in git:

1. type blob = array

2. type tree = map<String,tree/blob>

3. type commit = struct{ parent: array, author:String, message:String, snapshot: tree }

4. type object = blob | tree | commit

    ```
    objects = map<String,object>
   
    def Store(1):
    	id = sha1(1)
    	object[id]=1
   
    def load(id):
    	return object[id]
    ```
   

Important commands in git CLI.

• To intialise a directory as git repository:

   mkdir new_repo
   cd new_repo
   git init .
  

• Check status

   git status
  

• Adding the files to staging area.

   git add hello.txt
  

• Removing the files to staging area.

   git reset
  

• Commiting the staged code to git.

   git commit -m "checkin-tag"
  

• Checking the log beautifully

   git log --all --graph --decorate --oneline
  

• To get content or type and size information for repository objects.

   git cat-file -p 4365fa2
  

• Download the master branch

   git checkout master
  

• Check the diff.

   git diff 4365fa2 master
  

• Create branch.

   git branch brn01
   git branch -vv
  

• To see available branches local.

   git branch 
  

• To see available branches remote.

   git branch -r
  

• To merge the brn01 with header branch.

   git merge brn01
  

• Then solve the merge conflict using editor.

   git merge --continue
  

• .git directory content

   ls .git 
  

• Configuring remote

   git remote
   git remote add <name> <url>
   
   git remote set-url <remote_name> <remote_url>
   eg: git remote set-url origin https://git-repo/new-repository.git
  

• Uploading to remote

   git push <remote>  <local branch>:<remote branch>
   git push -u origin master
  

• Setting up the upload (remote) branch (deprecated in recent git version)

   git branch --set-upstream-to=origin/<branch> master
  

• Cloning to local

   git clone <url>
  

• To fetch the content from remote repository.

   git fetch
  

• pull = fetch + merge

   git pull
   git pull origin master
  

• To show the different objects. Here, we can see the last commit ka diff.

  git show
  

• To save the current working changes to staging and get back to HEAD as well.

   git stash
   git stash pop
  

• Use binary search to find the commit that introduced a bug.

   git bisect
  

• Adding gitignore file that list which files to not include in version control.

   touch .gitignore
  

• Difftool to check the difference.

   git difftool
  

• To beat the mismatch histories conflict while pulling/merging:

   git pull origin master --allow-unrelated-histories
  

• To work with git tags

   git tag
   git tag -D sample_tag
  

• Github is a host for git repositories.

• Sourcetree is one of the best git merging tool.