Git

General

Initialize Repository

git init

Get Help

git --help
git config --help

List configurations

git config --global -l

Set configuration

git config user.name laiboonh

Set editor. This editor is for OSX only

git config --global merge.tool opendiff

See history. Refer below for more advance commands

git log

Stage

Stage files

git add README.md
git add -A

Unstage files. HEAD refers to last commit on the current branch/timeline you are currently on.

git reset HEAD <file>

To completely stop tracking and remove file from repo (and filesystem)

git rm -f test.log
git commit -m "removed test.log"

To completely stop tracking the file only (file remains in filesystem)

git rm --cached test.log
git commit -m "removed test.log"

Reset changes

git checkout -- README.md

Commit

Commit files

git commit -m "commit message"

Undo last commit. Reset into staging. ^ does not work in DOS, use ~ instead.

git reset --soft HEAD^
git reset --soft HEAD~

Undo last 2 commits.

git reset --soft HEAD~~

Undo last commit and remove all changes

git reset --hard HEAD~

Add file to last commit and amend last commit message

git add git.ignore
git commit --amend -m "new message"

Show unstaged difference since last commit

git diff

Show staged difference since last commit

git diff --staged

Remote

View current remotes

git remote-v

Add remote

git remote add <name> <address>

Remove remote

git remote rm <name>

Push to Github. -u is used so that you can do git push subsequently without arguments.

git push -u <name> <branch>

Pull down changes from Github

git pull

Branching.

To see all remote branches

git branch -r

To see more details about remote branches

git remote show origin

Delete remote branch

git push origin :shopping_cart

Delete local branch

git branch -d shopping_cart

Cleanup stale branches

git remote prune origin

Link up to remote branch of your choice

This would push local staging to heroku-staging remote staging branch

git push heroku-staging staging

This would push local staging to heroku-staging remote master branch

git push heroku-staging staging:master

After branching HEAD is still at the master timeline. Switch to cat timeline.

git branch cat
git checkout cat

shortcut

git checkout -b cat

Merge branch into master. If nothing has happened in the master branch since. Git will "fast-forward" the HEAD pointer.

git checkout master
git merge cat

If there were changes that happened in master since. Git will do a recursive merge and create a log message that branch have been merged in.

We can choose to do a rebase instead. Refer to rebase section below first.

This will allow cat branch to have all the commit in master since, and then have our commit in the cat branch.

When we merge in master branch, it will be a smooth fast forward instead of a merge commit

git checkout cat git rebase master git checkout master git merge cat

Scenarios

Colleague committed first, no conflicts.

git pull does a git fetch which creates an origin/master branch and then a git merge origin/master

git pull
git push

Colleague committed first and touched the same file

git pull will fail to merge. we edit the affected file and then git commit -a

git pull

Collaborating on a remote branch. If work is going to last several days you will want to push it to Github and start tracking it.

git checkout -b shopping_cart
git push origin shopping_cart

Tag

List all

git tag

Checkout a tag

git checkout v0.0.1

Add a tag

git tag -a v0.0.3 -m "version 0.0.3"

Push to remote

git push --tags

Rebase

Fetch all latest change from remote into local branch origin/master

git fetch

git rebase will

1. Move all changes which are in master but not in origin/master to a temporary area
2. Run all origin/master commits one at a time
3. Run all commits in the temporary area one at a time git rebase

If there were conflicts resolve the conflicts by editing the affected files

git add index.html
git rebase --continue

Viewing logs

git config --global color.ui true will emphasize the SHA hash

git log --pretty=oneline for one liner easy viewing

git log --oneline -p for more details on each commit

git log --oneline --graph for visuals on when merge happened

git diff HEAD~5 for difference between current state and 5 commits ago

git diff master cat for difference between branches

git blame index.html --date short

use aliases for all these tricky commands

git config --global alias.mylog "log --pretty=format:'%h %s [%an]' --graph"