Develop with Git on a Google Code Project git, svn, google, code

rex

Develop with Git on a Google Code Project
  
Tuesday, May 20, 2008 | 8:48 AM

By Benjamin Lynn, Google Developer Programs

Do you often work offline? Wish you could make local commits that you can reorganize and upload later? Would you like to have your own copy of the entire history of the project which you can peruse at your leisure?

Do you want to serve code and its history to others? Have changes you want to share but it's too early for the public?

Working on several issues in parallel? Need to save some of those experimental changes after all? Need to create, merge, clone and otherwise manipulate branches cheaply and offline?

You can do all this, and more, with Git, a version control system rapidly growing in popularity. You can readily find Git tutorials, but since I'm writing this post, I'll shamelessly plug my own guide to Git!

Although Google Code natively speaks Subversion, you can easily use Git during development. Searching for "git svn" suggests this practice is widespread, and we too encourage you to experiment with it.

We focus on importing a complete Git repository from a Google Code project organized in the recommended fashion. The git-svn manpage thoroughly describes how to handle other cases such as nonstandard layouts, importing only a few revisions, sharing exported repositories, and so on.
1. ImportFirst we perform the equivalent of a svn checkout. In an empty subdirectory, run:

1. $ git svn clone --username your-name -s https://your-project.googlecode.com/svn
   
2. # older versions of git: replace "-s" with "-Ttrunk -bbranches -ttags"

复制代码

Like a Subversion checkout, you now have a local copy of your project. Unlike a Subversion checkout, you also have a local copy of the entire history of the project. Try:

1. $ git log          # print summary of history
   
2. $ git diff HEAD^^  # diff against two revisions ago
   
3. $ gitk             # graphical history browser
   
4. $ qgit             # Qt-based history browser

复制代码

These read from local disk, and work even when you're offline.
2. DevelopYou now have a fully fledged version control system at your fingertips. You can checkpoint locally. You can create, merge, and destroy branches cheaply. You can checkout long-lost ancient code. You can stockpile and reorganize your commits.

Any Git tutorial teaches these abilities. We'll content ourselves with simple examples.

First, the basics. Edit code as usual, but if you add or remove files, type:

1. $ git add FILENAME...

复制代码

or

1. $ git rm FILENAME...

复制代码

There's no need to inform Subversion as git-svn will do so later. In fact, we only talk to Subversion via git-svn, and never run pure svn commands.

The only other git command you must know is:

1. $ git commit -a

复制代码

which saves the current state of your project locally. You can see them with git log. Commit early and commit often!

Now for a couple of tricks. Let's say you've made several commits and suppose you want to undo the last one:

1. $ git reset --hard HEAD^

复制代码

Or suppose you want to get a certain file from five commits ago:

1. $ git checkout HEAD~5 foo.c

复制代码

We've barely scratched the surface. There are countless other features worth learning, particularly Git's extraordinary lightweight branches.
3. UpdatePeriodically, you should get online and fetch the latest changes from Google Code with:

1. $ git svn rebase   # think "svn update"

复制代码

4. ExportSubmit your commits to Google Code with:

1. $ git svn dcommit  # think "svn commit"

复制代码

This converts each of your Git commits into Subversion commits and uploads them, provided your repository is up-to-date. To keep working, go back to step 2.
Stay Tuned!We've seen it's easy to setup Git with a Google Code project. If distributed version control systems sound intimidating, the above is a great way to get your feet wet. You can always delete the directory and go back to Subversion.

But what if you keep your project in a Git repository, and you want to export it to Google Code? So you'd have a canonical read-only Subversion mirror of your project?

Exporting a Git project to Google Code requires only a handful of commands. We'll show you how in a future post.

rex

常用的如下：

1. $ git svn clone --username your-name -s https://your-project.googlecode.com/svn
   
2. #首次将google code 同步到本地
   
3. 
   
4. $ git add FILENAME...
   
5. # 添加新文件
   
6. 
   
7. $ git rm FILENAME...
   
8. # 删除文件
   
9. 
   
10. $ git commit -a -m "some comment"
    
11. # 落实文件，并添加评论，作为本地新版本；
    
12. 
    
13. $ git svn dcommit       
    
14. #向svn库中提交。
    
15. 
    
16. $ git svn rebase   # think "svn update"

复制代码