Git

Git States

Modified - are files that have been changed but not yet committed.

Staged - are modified files marked to be committed with the next commit.

Committed - are files stored in the database.

Setting Up Repositories

Initialise a New Repository

git init

Clone an existing repository

git clone https://github.com/repo.git

Checkout an existing repository into a non-empty directory

cd ${non-empty directory}

git init .

git remote add origin git@server2:/git/control-repo

git fetch origin

git checkout production

Using a Repo

Add a file to staging

git add filename

Add files to the master repository

git commit -m "Details of changes"

Show status of Repository

git status

# Short

git status -s

Ignoring files

cat .gitignore

*.[ao]

# Start lines with a slash to prevent recursion

/

# Slash at the end denotes a directory

directory_name/

# Regular Expressions

* Zero or more characters

? one or more characters

** Match nested directories a/**/z will match a/z, a/b/z, a/b/c/z

! Negate a match

Displays the actual changes rather than the changed files that git status does

git diff #Compared working directoy with staging

git diff --staged # Compares staged to last commit

Removing files

#Remove files from hard drive as well.

git rm file

git commit

#Remove files from git tracking but not hard drive

git rm --cached file

git commit

Rename a file

git mv old_file new_file

Viewing Commit History

git log

-p #Show differences

-2 # Limit to 2 entries

--stat #Abbreviated stats

--pretty= #Changes the format of the output.

oneline

short

full

fuller

format

--graph

Limiting Log Output

-(n) Show only the last n commits

--since, --after Limit the commits to those made after the specified date.

--until, --before Limit the commits to those made before the specified date.

--author Only show commits in which the author entry matches the specified string.

--committer Only show commits in which the committer entry matches the specified string.

--grep Only show commits with a commit message containing the string

-S Only show commits adding or removing code matching the string

Undoing Things

The --amend will amend your last commit using the staging area. If no files have been changed or added, only the commit message will be amended.

git commit --amend

Unstage a staged file

git reset HEAD filename

Unmodifying a Modified File

git checkout -- filename

Working With Remotes

List remote servers

git remote

git remote -v

Adding a Remote Repository

git remote add shortname URL

Then you can use git fetch to pull down new files from shortname

git fetch shortname

Fetching and Pulling from Remotes

Once a repository has been cloned, you can run git fetch to pull new content. This only places the new content into your local repository. You still need to merge it into your work.

git fetch remote_name

git pull will fetch the remote content and attempt to merge the content automatically.

git pull remote_name

Pushing to Remotes

Once you finished working locally and you have commited your content, you can push your changes to the remote server.

git push remote_name branch_name

git push origin master

Inspecting a Remote

Finding out more about a remote can be done with git remote show.

git remote show origin

Removing and Rename Remotes

Rename

git remote rename old_name new_name

Remove

git remote remove name

Tagging

You can tag specific points in history as important. Maybe a release point like v1.0

List tags

git tag

Searching for tags

git tag -l "v1.8.5*"

Creating Tags

Git uses 2 types of tags. Lightweight and annotated. Annotated is the recommended tag as it has a lot more information and are stored as full objects.

git tag -a v1.4 -m "Info message"

git show tag v1.4

Tagging after sever

All other commits can be done by specifying the commit checksum.

git tag -a v1.4 fd4dfa7

Sharing Tags

git push does not transfer tags to remote servers. You need to explicitly push tags to remote servers.

#Push a single tag

git push origin v1.4

#Push all tags

git push origin --tags

Checking out Tags

You can't really check out tags but you can create a new branch from a tag.

git checkout -b branch_name tag_name

Aliases

Aliases can be created as shortend versions of regular commands.

git config --global alias.co checkout

This would make git checkout the same as git co.

External commands can be run with an ! infront of it.

git config --global alias.visual '!gitk'

Configure a Git Server

Git can be server using the protocols SSH, HTTP, Git and Local. The Git documentation has all this information and so we will just do a quick run through.

Create a bare repository by either cloning an existing repository or creating a new one.

git clone --bare existing_repo new_repo.git

git init --bare new_repo.git

You can now clone from this repository.

git clone user@server1.grow4.co.uk:/apps/git/new_repo.git/