1.1 Clone a single branch from a remote repository

$ git clone -b develop --single-branch [email protected]:soimort/example.git

Or: (if there’s already an existing remote, just checkout the branch)

$ git checkout -b develop origin/develop

Source: http://stackoverflow.com/a/8142070/1114972

1.2 Force update of a repository brutally (and throw away any uncommitted local changes / commits)

This operation does not require configuration of git user name / email. (Thus could be useful on an app server.)

$ git fetch
$ git reset --hard origin/master

Source: http://stackoverflow.com/a/17713604/1114972

1.3 Create a new, unrelated branch to work on (e.g., gh-pages for GitHub Pages)

Personally I would prefer to put an orphaned branch in a separated directory so that it can never mess up with the major codebase.

$ mkdir gh-pages && cd gh-pages
$ git init
$ git remote add origin [email protected]:soimort/example.git
$ git checkout -b gh-pages
...
$ git push origin gh-pages

1.4 Delete a remote branch

$ git push origin :branch-to-be-deleted

1.5 Clean obsolete references

Show all stale branches:

$ git branch -r

Update local references to the remote repository: (and delete obsolete references that are removed in the remote repository)

$ git fetch --prune

2.1 Update all submodules

$ git submodule update --recursive --remote

3.1 Revert (uncommitted change of) a single file

$ git checkout file

To avoid confusion with a branch name, use:

$ git checkout -- file

3.2 Unstage any staged changes for a file

$ git reset file

3.3 Stage the removal of a file (but leave it untracked in the working tree)

$ git rm --cached file

4.1 Get a Pull Request (and create a feature branch for the PR)

$ git fetch origin pull/123/head
$ git checkout -b feature-branch FETCH_HEAD

Or:

$ git fetch origin pull/123/head:feature-branch
$ git checkout feature-branch

4.2 Push an empty commit to trigger a GitHub Pages rebuild

$ git commit -m 'rebuild pages' --allow-empty

4.3 Download a specific folder in a GitHub repo

$ svn export https://github.com/user/repo.git/trunk/path/to/something

5.1 Compare two arbitrary files

$ git diff --no-index file_a file_b

5.2 Create the archive of a tag

$ git archive --format=tar.gz --prefix=foobar-1.2.3/ v1.2.3 > v1.2.3.tar.gz

5.3 Remove untracked files and directories from the working tree

$ git clean -fd

To remove ignored files as well:

$ git clean -fdx