Git recipesEdit

Initializing a repository based on an existing directory

cd path_to_directory
git init
git add .
git commit

Topic branches

# create a new branch
git branch doc-updates

# list branches
git branch

# switch to new branch
git checkout doc-updates

# note: could have done "git checkout -b doc-updates"
#       to create new branch and checkout in one step

# make a change
echo "more docs" >> greeting.txt 
git add greeting.txt 
git commit -m "More docs"

# one more change
echo "even more docs" >> greeting.txt
git add greeting.txt 
git commit -m "Even more"

# switch back to master branch
git checkout master

# merge topic branch (two commits)
git merge doc-updates

# delete topic branch
git branch -d doc-updates

Moving an unpublished topic branch from one machine to another with git bundle

$ git co my_topic
$ git bundle create bundlefile master..my_topic
$ scp bundlefile host:path/to/repo
$ ssh host

Now on the other host:

$ cd path/to/repo
$ git bundle unbundle bundlefile
$ git co -b my_topic sha1_hash_of_bundle_HEAD

Creating and submitting a patch via email

For example, making a simple change to Git itself:

# change to local checked-out copy of repository
cd git.git

# update
git fetch # or "git pull" if you want to merge as well

# make changes on a local topic branch
git checkout -b my_topic origin/master

# make/test changes
vi file_to_be_changed

# review changes
git diff

# commit changes
git add file_to_be_changed
git commit -s

# run test suite
make clean && make test

# prepare patch
git format-patch origin

# send the email (dry run, test run)
git send-email --dry-run --to patch_file
git send-email --to patch_file

# send the email (for real)
git send-email --to patch_file 

For submitting patches to Git itself I’ve set up some aliases as described in "Git quickstart". These would be used as follows:

# send the email (dry run, test run)
git send-email --dry-run --to me patch_file
git send-email --to me patch_file

# send the email (for real)
git send-email --to git --cc junio patch_file

For patch series, you can pass the --compose switch to git-send-email to compose an introductory message that will be prepended to the rest of patch series.

I also recommend setting the format.numbered configuration variable to true as described in "Git quickstart"; this is useful if you group your changes together in topic branches (and you probably should when tracking an upstream project).

To get patches to send correctly from my local machine I need to configure my SMTP settings as described in "Git quickstart". I also needed to install the Net::SMTP::SSL Perl module (see "Installing Net::SMTP::SSL for sending patches with Git over secure SMTP").

Tracking upstream changes

# fetch new commits from upstream
git fetch

# view what's happened on master branch since last time
git co master
git log HEAD..origin/master

# fast-forward local checkout to upstream HEAD
git merge origin/master

# merge or rebase topic branches as appropriate
git co my_topic_branch
git rebase origin/master