I have forked a repository on github some time ago, made a small change and pushed the change back to my github fork. The original repository has changed since. I would like to merge the changes from the original repository to my fork.
I am new to both git and github, and I need specific commands how to do it.
git remote add {name} {Public Clone URL}
git pull {name} master
git push
Example:
git remote add bret git://github.com/bret/watir.git
git pull bret master
git push
Simply add original repo as a remote and merge your fork with it; then push merged fork to github.
There's also a ruby gem for easier github operations. You can merge upstream with one call...
git pull origin master
will do the job creating additional merge commit. If you do not have conflicts and do not want to create a rejoin (with additional 'merge' commit) for every commit that you push then rebase is more preferred. You can do it with the Git Gui+gitk. Just fetch remote with Git Gui then open history with gitk and create temporary r_master branch at remotes/origin/master fetched. Finally, call git rebase r_master in the git bash. This will place your commits on top of the remote modifications. You are ready to push and remove the r_master.
This comment suggests that there are shortcuts for this flow.
来源：https://stackoverflow.com/questions/867831/merge-changes-from-remote-github-repository-to-your-local-repository