Githandson

Git Hands-on

All of these exercises should be followed on naf-school03 using your school account

Note that lines beginning with a $ sign implies a shell command!

Exercise 1 (Configuration)

• Login to gridkalogin01
  • ssh schoolx@gridkalogin01.desy.de

• Create project
• $ mkdir project
• $ cd project

• Configure git
  • $ git config --global user.name "Your Name"
  • $ git config --global user.email you.email@domain

• Examine the gitconfig file
• $ cat ~/.gitconfig

• Optional extras for config (and obviously editor is mutually exclusive)
  • $ git config --global color.ui auto # If you like colours!
  • $ git config --global alias.co checkout
  • $ git config --global alias.st status
  • $ git config --global alias.ci commit
  • $ git config --global core.editor emacs # flame bait
  • $ git config --global core.editor vim

Exercise 2 (Basics)

Let's commit some stuff to git...

• Ini new repo
  • $ git init
  • $ git status

• Create new file and commit it
  • $ touch readme.txt
  • $ echo "hello" > readme.txt
  • $ git commit

• Can't commit? Submit file to staging area first
  • $ git add .
  • $ git commit

• Avoid opening editor and submit the change directly to repo:
  • $ echo "some new change">> readme.txt
  • $ git commit -am "fast commit to repo"

• Examine how to revert changes in working tree:
• Remove file from staging area:
  • $ echo "bye" >> readme.txt
  • $ git status
  • $ git reset
• Remove file from staging area and and drop all changes, which were staged in working dir, take the last commit from local repo
  • $ git reset --hard
• Discards all history and changes back to the specified commit
  • $ git reset --hard [commit]
• Drop all local changes staged and unstaged, take the last commit from repo:
  • git clean -df ( -d Remove untracked directories in addition to untracked files)
  • git checkout -- .

Exercise 3 (Working with remote repository)

• Clone the remote repository and examine the log
  • $ git clone gitolite3@gridkapuppet01:test2.git
  • $ git log

• Look in .git directory at the config file
  • edit config file and delete [remote "origin"] section
  • add remote repository by doing:
  • $ git remote add origin gitolite3@gridkapuppet01:test2.git

• Add a new file to local repository and submit the changes to remote:
  • $ git add <new file>
  • $ git diff HEAD
  • $ git commit -am "some comment"
  • $ git push -u origin master ( -u - set-upstream ref)

• Drop all local changes and get the latest commit from remote repo:
  • $ git fetch origin
  • $ git reset --hard origin/master
• try:
  • $ git fetch
  • $ git rebase

Git cheat sheet

Git configuration

• Git levels:

/etc/gitconfig - global git config for any user

~/.gitconfig -user specific

~/repo/.git/config -repo specific

each level ovewrites prevous.

git config --global user.name "Your Name"

git config --global user.email you.email@domain

git config --global color.ui auto # If you like colours!

git config --global alias.co checkout

git config --global alias.st status

git config --global alias.ci commit

git config --global core.editor emacs

Git basics

git init                        - create new local repo 
git clone /path/to/repository   - check out a repository. Clone creates a new git repository by copying an existing one located at the URI you specify.
git clone https://github.com/   - clone repo from github 

git status                      - List the files you've changed and those you still need to add
git add <filename>              - add specified file to staging area 
git add .                       - add all subdirectories and files recursivly
git commit                      - commit the staged files 
git commit -am "some comment"   - stage changes and commit in one step
git rm <filename>               - remove deleted file
git reset                       - removes all added files from staging area, keeps the changes 
git reset --hard                - removes all added files from staging area, drops the local changes after last commit
git reset HEAD^                 - the changes a now only in working dir, HEAD and Index moved one step back 
git reset --hard HEAD           - deletes last commit as it were never happend 
git checkout -- .               - discards all local changes which are not staged 

git help                        - Help for most commonly used git commands
git help <command>              - Detailed help for specified command

git init --bare --shared        - Creates empty repository meaning no working directory in it. 
git remote add origin REMOTEURL - git remote add creates an entry in your git config that specifies a name of a particular URL of the remote 
git remote rm origin            - removes added remote repository
                                  git repo. This command can be used only after creation of local repo with git init or git clone. 
git remote -v                   - This should show you all of the push/fetch remotes for the project.
git diff master origin/master   - compare local branch with remote 

git branch                      - list of all local branches 
git branch -a                   - list of all branches including remote 
git checkout -b <branchname>    - creates new branch and switches to it 
git checkout <branchname>       - switch to another branch 
git branch -d <branchname>      - delete branch 
git push --all origin           - push all branches to remote repository