Git Basics

February 7, 2016

History of Version Control

Configuring Git

Specifity overwrites the config.

System-level configuration

git config --system
# Stored in /etc/config or c:\Program Files(x86)\Git\etc\gitconfig

User-level configuration

git config --global
# Stored in ~/.gitconfig or c:\Users\<NAME>\.gitconfig

Respository-level configuration

git config
# Stored in .git/config in each repo

Useful Commands

git config --global --list
git config --global "Pere Pages"
git config --global "[email protected]"
git config --unset core.autocrlf

Working locally

git init

Add files

# only modified
 git add -u
 # modified and new
 git add --all
 git add -A
 git commit -m "files changed"
 git log
 # comparing with the last cmomit
 git diff dd68210..a234c4 
 # The lataest commit is called HEAD
 git diff HEAD
 # the prior the latest one
 git diff HEAD~1 
 # before the prior of the latest one
 git diff HEAD~2

Undoing Changes

 # Undoing one file
 git checkout README.txt
 # Undoing all changes in the files but not removing the staged or discarding
 git chekcout .
 # All changes back to the HEAD (the last commit) losing the staged and therefore discarding
 git reset --hard 
 # Goes back to one commit before the last one (HEAD) but keeps the staged files
 git reset soft HEAD~1

Discarding changes

# what are we going to discard?
git clean -n 

# discard changes
git clean -f

# discard all changes to the last commit (HEAD)
git reset --hard


Ignoring files and folders


Working Remotely

Adding a remote origin

git remote add origin
# Set a new remote

git remote -v
# Verify new remote


git clone

# See the log in one line
git log --oneline


# Count lines
git log | wc -l

git log --oneline --graph

git shortlog -sne

Viewing Commits

git show HEAD
git show HEAD~1

git log --oneline
git show 5642626

git remote
git remote -v

Git Protocols

  • http
  • https
  • git
  • ssh
  • file
[remote "origin"]
url =
fetch = +refs/heads/*:refs/remotes/origin/*
[branch "master"]
remote = origin
merge = refs/heads/master
git branch

# display remote branches
git branch -r

git tag

Fetching from a remote

git remote -v
git remote add origin
git fetch
# If there's more than one remote repository
get fetch origin

# checking the log of the remote master
git log origin/master

git merge origin/master

Pulling from a remote

git fetch
git merge origin/master

is the same than doing

git pull origin master

Pushing to a remote

git push origin master

Creating and verifying tags

git tag v1.0

# signed tag
git tag -s v2.0 

# check signature of tag
git tag -v v2.0

Pushing Tags to a Remote

Tagging gives us stable points

git push --tags

Branching, Merging and Rebasing

Visualizing Branches

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

# We can create alias in git
git config --global alias.lga "log --graph --oneline --all --decorate"

Creating Branches

git branch feature1
git checkout feature1

# create branch keeping not staged files
git branch -b feature1

Differences betwee branches and tags

Tags always stay on the same commit

Renaming and deleting branches

# renaming is the same than moving
# renaming LOCAL branch
git branch -m <oldname> <newname>
git branch -m fix1 bug1234
# deleting the branch
git branch -d bug1234

Recovering deleted commits

You can use this technique, the reflog one, until 30 days of the commit. Than you lose the changes.

git reflog
git branch bug1234 5a78c8b

Stashing Changes

git stash
git stash list
git stash apply
# it's the same than apply but gets rid of it in the list
git stash pop

git stash drop
git stash branch feature2

Merging Branches

kdiff3 is a merging tool that can be used.

git merge feature1
git branch -d feature1

git merge feature2_additional
git diff --cached
git commit -m "merged"


git rebase master

Cherry picking changes

Apply only a specific commit

git cherry-pick 6fa4324

Creating a remote branch

We can do it just pushing the changes

Deleting a remote branch

git push origin :my-branch-to-delete

Useful snippets

Remove all untracked files

# Show what will be deleted with the -n option:

git clean -f -n
# Then - beware: this will delete files - run:

git clean -f
# If you want to also remove directories, run git clean -f -d or git clean -fd

# If you just want to remove ignored files, run git clean -f -X or git clean -fX

# If you want to remove ignored as well as non-ignored files, run git clean -f -x or git clean -fx

# Note the case difference on the X for the two latter commands.

Undo working copy modifications of one file in Git

# You can do it without the -- , but if the filename looks like a branch or tag (or other revision identifier), it may get confused, so using -- is best.
git checkout v1.2.3 -- my-file.js         # tag v1.2.3
git checkout stable -- my-file.js         # stable branch
git checkout origin/master -- my-file.js  # upstream master
git checkout HEAD -- my-file.js           # the version from the most recent commit
git checkout HEAD^ -- my-file.js          # the version before the most recent commit

Stop tracking a specific file that we don’t want to commit

git update-index --assume-unchanged <file>

# update
# To undo and start tracking again (if you forgot what files were untracked, see this question):

git update-index --no-assume-unchanged [<file> ...]

Merge two branches and in case of conflict get the other branch changes

git merge -X theirs <branch>

Merge two branches and in case of conflict get the our changes

git merge -s ours <branch>

Change the date of a commit

git commit -am "message of the commit" --date="2015-11-28 11:34:12"