git and git svn quick Memo

git and git svn Quick Memo

git quich memo
git svn quich memo

git quick memo

clone the github repository

     git clone https://github.com/username/project.git

revert local commit (with local chang recorded by --soft). Note: reset: move to the git state node only, no file change. revert: move to the git state to node with file update by merge.
```
     git reset --soft HEAD^
     
```
revert local commit (local chang is gone by --hard)
```
     git reset --hard HEAD^
     
```

Local new repository (which I can use for a remote repository) tips

Set up repository (you are in the repository directory.)

     mkdir -p ~/git_repository/sample/project_1
     cd ~/git_repository/sample/project_1
     #
     # --bare is for remote repository. If no --bare, I got the
     # following error when push
     #    refusing to update checked out branch: refs/heads/master
     #
     git init --bare

Clone and use it (you are in your work directory.)

     mkdir -p ~/work/project_1
     cd ~/work/
     git clone ssh://username@localhost/home/username/git_repository/sample/project_1
     # Now you have your local git work project
     # Add and push/pull

origin/master, (fetched), master

origin/master: on the remote git server, a branches called origin/master
(fetched): local fetched from origin/mster
master: the local current code. a branch called master

Assume the following state

     A--B--C--D    <- origin/master (on remote)
     ============================================================
     A--B--C       <- (fetched) (local)
     ============================================================
     A--B--C
            \---E---F  <- master (local)

fetch: get origin/master to (fetched), but not to the master

     A--B--C--D
     ============= fetch syncs remote to fetch
     A--B--C--D
     ============================================================
     A--B--C
            \---E---F  <- master (local)

rebase: (fetched) to master

     A--B--C--D     <-- origin/master
     =============
     A--B--C--D
     ============= rebase syncs fetched to master (local) and recommit local
     A--B--C--D
               \---E---F  <- master (local)

detahched: The head is not at the branch (leaf). Note: a master is just a branch points to the end of commit.

head is not at the master

     A--B--C--D--E---F  <- master (local)
              ^
              |
             head

git checkout master moves the head to the master (branch)

     A--B--C--D--E---F  <- master (local)
                     ^
                     |
                   head

unpulled commits: The head is not at the branch (leaf). Note: a master is just a branch points to the end of commit.

When fetched and master have a difference, there will be unpulled commits. G and H are unpulled commit. To solve this state, git rebase.

     A--B--C--D--E--F--G--H     <- fetched
     ======================
     A--B--C--D--E--F  <- master (local)
                    ^
                    |
                  head

git rebase resolves the difference between fetched and master.

     A--B--C--D--E--F--G--H     <- fetched
     ======================
     A--B--C--D--E--F--G--H  <- master (local)
                          ^
                          |
                        head

git svn quick memo

get svn repolitory local with git

     % git svn clone svn+ssh://svn.repository/svnroot/project/trunk/src

or only a part of it

     #-- excluding excluding_dir from svn control
     % svn chechout svn+ssh://svn.repository/svnroot/project/trunk/src
     % cd src
     % svn update --set-depth exclude excluding_dir
     #-- partial git svn control
     % git svn clone svn+ssh://svn.repository/svnroot/project/trunk/src/excluding_dir

(use magit, emacs frontend)
update (sync) with svn repository
```
     % git svn rebase
     
```

local commit

     % git svn commit

if some conflict or need to rebase, but not clean.

     # -- push local change to stash
     % git stash
     # -- pull and update local
     % git svn rebase
     # -- merge pushed local change on stash
     % git stash pop
     % git svn commit

push the local commit to svn repository
```
     % git svn dcommit
     
```

squash (merge) local git commit to one svn commit (recent 10)

     % git rebase -i HEAD~10
     # -- Then an editor will popup.
     #    Replace keyword to squash where you want to squash and save.

Note: 'git svn rebase' and 'git rebase' are totally different.

get the specific revision file from the svn repository

     % git show REV:filename
     % # Ex. see revison HEAD -10's foo.cpp file.
     % git show HEAD~10:foo.cpp

Emacs integration
- To configure magit, add the following line to ~/.emacs file.
```
     (autoload 'magit-status "/magit/path//magit" nil t)
     
```

git difftool

if you use a diff program for git, e.g. xxdiff

      % git config diff.tool xxdiff
      % git difftool

If you don't to want to be prompted every time,

      % git config difftool.prompt false