Version Control

Category: /knowledge /development
Tags: development

Git

Basics ——— Staging area: between working tree and git repo, buffer the changes you want to commit to repo.

Create a repo:

mkdir mysite
cd mysite
git init 
git add .
git commit -m "initialize the project to git"

Add a file, commit the change, and display the log

git add my_first_file.txt
git add -i # interactive mode
        -p # patch mode

git commit -m "add my first page"
git commit -m "add my first page" -a 
# -a means take the most current version of the file in the working tree

git status # check status 
git log
git log --pretty=oneline

list all files in a repo

git ls-tree -r master --name-only

check logs

git log
git log -10 # last 10 entries
git log <commit hash>
git log --since="5 days"
git log --before="5 hours" -l # list changes older than 5 hours
git log hash_1..hash_2
git log has_id..HEAD or 
git log has_id..

git log --pretty=format:"%h %s" 1.0..HEAD
# %h is hash, %s is the first line of the commit log, the subject
git log --pretty=oneline

git log -l HEAD^^^
^: acts like a minus one
~N: subtracts N from the commit name

diff files

git diff # compare working area with staging area
git diff --cached # compare staging area with repo
git diff HEAD    # compare working area with repo

git diff --stat 1.0 #prints some statistics against tag 1.0
# default is HEAD

git blame $file_name
git blame -L <start>,<end> $file_name
git blame -L <start>,+10 $file_name # show 10 lines of code
git blame -L "/<\/body>/",+10 $file_name # support regular expression

git blame -M $file_name 
# detect lines that have moved/copied within the same file

rename/move files

git mv $source $destination

list conflicted files

git diff --name-only --diff-filter=U

Undo commits

git commit -C HEAD -a --amend
# -C: use the log message from the commit specified, HEAD
# -c: launch an editor
# it can only be done for the last commit

For previous commit to undo, use git revert

git revert -n HEAD
git reviert -n <hash_name>
git commit -m "revert 2 commits"
# you need to explain why you do the revert

If you commit a private information and want to take it back, do git reset

git reset --hard HEAD^ # reset TWO commits
git reset --soft # stage all the previous commits but not commit them.
# you still have a chance to modify the previous commit
# by adding to or taking away from it. 

Remote server repository

Create a remote repository

in remote server directly,

cd /opt/git
mkdir $prj_name.git
cd $prj_name.git
git init --bare --shared

Or, if I want to add an existing git project to a remote server,

 git clone --bare $prj_name /tmp/$prj_name.git
 scp -r /tmp/$prj_name.git $remote_server:$port/opt/git/

If the remote repository is setup already, origin is the default remote repository name, just an alias to the full name

 git remote add <remote repo> <repo url>
 e.g.
 git remote add origin $remote_server:/opt/git/$prj_name.git
 git push origin master
 git remote add tv tv:/opt/git/${prj_name}.git
 git push tv HEAD

To checkout a remote git repo

To check out the code via ssh:

git clone $USER@192.168.1.7:/opt/git/$prj_name.git

If ssh is not on default port number, check svn+ssh below to see how to setup .ssh/config.

To commit changes to a remote repo

git push origin master
git push --dry-run # see what changes will be pushed

List remote repositories

git remote -v

or

git branch --remote --list
git branch -r  # show branches in the remote repository

or

git ls-remote --heads origin

check remote repo URL

git remote show origin
or
git config --get remote.origin.url

To update changes to a remote branch

git fetch <remote repo> 
# update the changes made in remote repo in your local repo, 
# it doesn't merge into not local working branch
# one usage:
# git fetch
# git diff ...origin

git pull <remote repo> 
# fetch changes and merge into local branch
# so it is actually a `git fetch; git merge`
typical usage:
git checkout master
git fetch
git diff origin/master
git pull --rebase origin master
or git rebase origin

delete a remote repo from current local working copy

git remote rm origin
git remote show

add repository to git hub

create a new repository in github

push an existing repository to github

 git remote add github https://github.com/teckoo/org_directory.git
 git push -u github master

Branches

create a branch:

# create a branch form the default 'master' branch in Git
git branch $branch_name master
# create a branch from tag
git branch $branch_name 1.0

switch to a branch

git checkout $branch_name

create a branch and check it out

git checkout -b $branch_name
# create a branch from the master branch
git checkout -b $branch_name master 

merge a branch

--squash: take all the commits and squash them into one commit

git merge --squash $branch_name

rebase, a replay ‘merge’ from another branch.

# stay in the place need to be merged
# e.g. merge RB_1.0 to master branch
git rebase RB_1.0

delete a branch

git branch -d $branch_name

rename a branch

git branch -m $branch_new_name $old_name

Submodule

It works similar to svn:external

git submodule
git submodule add $remote_mod_url $local_mod_name
git submodule init $local_mod_name
git submodule update $local_mod_name
git add $local_mod_name
git commit -m "update to track in submodule $local_mod_name"

Rebase

git rebase saves stuff from your current branch that isn’t in the upstream branch to a temporary area. Your branch is now the same as before you started your changes. So, git pull -rebase will pull down the remote changes, rewind your local branch, replay your changes over the top of your current branch one by one until you’re up-to-date.

git rebase
git rebase --continue # tell Git the conflict is resolved
[--skip|--abort]
git rebase --onto master your_branch # TODO: explain here

git rebase -i HEAD~3 # reordering commits
# to squash multiple commits into one,
# change 'pick' to 'squash'

# to break one commit into multiple commits
# change 'pick' to 'edit', save and exit to start the rebase
# run `git log -1`, then you can use `git reset HEAD^ to make more changes.
# git commit -m "message 1" -a
# git commit -m "message 2" -a
# git rebase --continue

Reflog

git reflog # list commits
git branch reflog-restored $commit_name
git checkout reflog-restored

Bisecting

git bisect start
git bisect bad
git bisect good $tag_name
git bisect reset # back to master branch
git bisect visualize
git bisect run $script

From SVN path

svn checkout url -- git clone url 
svn update       -- git pull      
svn commit    --  git commit -a

svn status  --  git status  
svn log | less  --  git log 
svn diff | less  --  git diff  
svn diff -rrev path --   git diff rev path   
patch -p0   --  git apply   

svn list url -- git show rev:path/to/directory 
svn list http://example.com/svn/branches/
  -- git branch
svn list http://example.com/svn/tags/
  -- git tag -l
svn import file://repo--  git add .  
svnadmin create repo  --  git init      

svn merge -c rev url -- git cherry-pick rev
svn merge -r 20:HEAD http://example.com/svn/branches/branch
  -- git merge branch

svn copy http://example.com/svn/trunk \
  http://example.com/svn/tags/name
  -- git tag -a name
svn copy http://example.com/svn/trunk \
  http://example.com/svn/branches/branch      
  -- git branch branch 

svn revert path -- git checkout path   
svn blame file  -- git blame file 
svn switch url  -- git checkout file|dir

git bash completion

In user home folder, do

mkdir .bash_completion.d
cp /usr/share/git/completion/git-completion.bash .bash_completion.d

To test, `. .bash_completion.d/git-completion.bash

to show branch name

PS1='[\u@\h \W$(__git_ps1 " (%s)")]\$ '

Undo things

undo staged, but not commit yet files

git reset HEAD file

or

git reset file
git reset .

Compacting, garbage collection

git gc # no change in history, optimize the storage
git gc --aggressive # if you want reduce size more

show global variables

git config --global --list # list all variables
git config --global user.name "C2 Programmer"
git config --global user.email "c2@teckoo.com"
git config --global color.ui "auto"
git config --global alias.ci "commit"
git config --global core.excludesfile ~/.gitignore

ignore files: edit .git/info/exclude

In global level: vi ~/.gitignore

# use wildcards
*~
*.pyc
*.swp
# can also ignore all folders and files under it
tmp/**/*

Resources

Subversion

How to setup an ignore list

edit multiple entries at a time: svn propedit svn:ignore .
set properties from commandline: svn propset svn:ignore "*.class" .
set from a file: svn propset svn:ignore -F ../dining3/.cvsignore .

Switch to Another Repository

You can then switch a current work directory to the new respository:

svn switch --relocate url-of-old-repos url-of-new-repos

Ref: http://svnbook.red-bean.com/en/1.1/re27.html

查看状态 Reviewing Changes - svn status

To see what files you have changed or added to your checked out work, use the update command:

svn status

If you want to compare current working directory with remote repository, run

svn st -u

If you want ot view changes

svn log -r r1:r2 | less

To get a list of the releases for a project.

svn list http://192.168.0.4/svn/repos/prj1/tags

Then to check out a release you would type:

svn list http://192.168.0.4/svn/repos/prj1/tags/0.1.0

Branches and Tags

merge changes from trunk to branches

Suppose I made some changes in trunk ‘edit.html’ at revision 62, I need to move it to prod branch ‘cms-social’, here is what I do

pwd
c2@local1:~/workspace/cms-social/channel_blog/templates/channel_blog

svn diff -c 62 https://c2@remote.teckoo.com/svn/c2/cmsite/trunk/channel_blog/templates/channel_blog/edit.html

I should see some changes between r61 and r62, then do

svn merge -c 62 $remote/edit.html
U    edit.html

or 
svn merge -r 61:62 $remote/edit.html

try before real action:

#suppose you're in trunk, want to merge some change in branch 'test'
svn merge --dry-run -r 1793:1867 $remote/myfile.ext

the simplest step: merge all changes from another branch

svn merge $remote

Now the change has been made in local branch, I need to commit to SVN repository,

svn commit

Then in prod server, I can do ` svn up ` to fetch the latest change

fix conflicts

After you do a merge, if there is a conflict, there will be three files in your folder,

post.html
post.html.mine
post.html.merge-left.r259
post.html.merge-right.r260

fix conflict in post.html, 如果不想保留你的修改, 可以直接用一个版本覆盖原文件 cp post.html.r259 post.html
cp post.html post.html.merge-right.r260
rm post.html.merge-left.r259
svn resolved post.html
svn commit post.html -m “your reasons here”

fix tree conflict

这个挺麻烦, 简单的办法是

svn resolve --accept working your_folder/files

但你可能丢失一个tree’s change history.

create a branch and work on it

$ svn copy https://c2@remote.mis.teckoo.com/svn/c2/cmsite/trunk \
           https://c2@remote.mis.teckoo.com/svn/c2/cmsite/branches/cms-only \
      -m "Create branch for CMS only."
Committed revision 353.
$ svn switch http://svn.example.com/repos/calc/branches/newbranch
At revision 353.

copy a directory to a branch

svn copy channel_blog https://c2@remote.mis.teckoo.com/svn/c2/cmsite/branches/cms-social

Tagging Projects or Creating Project Specific Versions

To create interim project releases, you must create “Tags” which identify a specify version of a project. This is done by making a virtual copy of a project in the tags directory. For example:

svn copy https://$svn_host/repos/$prj_name/trunk https://$svn_host/repos/$prj_name/tags/0.1.0 -m "Tagging the 0.1.0 release of the project" 

or from a revision

svn copy -r 1 $REPO/trunk $REPO/branches/somebranch \
  -m "Creating branch somebranch from revision 1 of trunk" 

move data from one repository to another

export/import

This way you get a clean copy without any history

svn export path/to/your_old_repo/mydir ./mydir
svn import ./mydir path/to/your_new_repo/$prj_name

dump/filter, keep history/tag/branches

svnadmin dump /svn/old_repos > ./repository.dump
svndumpfilter include path/to/docs --drop-empty-revs --renumber-revs --preserve-revprops < ./repository.dump > ./docs_only.dump
svnadmin load /svn/new_repos < ./docs_only.dump

<a href=http://stackoverflow.com/questions/417726/how-to-move-a-single-folder-from-one-subversion-repository-to-another-repository> StackOverflow </a>
Repository Maintenance
a detailed instruction

Recover deleted files

不常用, 记下来省得以后再找

 svn log –verbose | grep -A5 -B5 your_deleted_file.txt
 # find the revision number above
 svn up -r number_found_above your_deleted_file.txt

Getting a list of projects

svn list --verbose file:///opt/svn/$prj_name/

Checking Out a Project - svn checkout

svn checkout file:///repository_name/$prj_name/trunk $prj_name #note the 'trunk' folder which is under '$prj_name'
svn checkout https:c2@remote.mis.teckoo.com/svn/proj_repo/trunk $prj_name

Add a New Project - svn import

Directory structure is like this:

\$prj_name 
  \branches
  \tags
  \trunk

type the following:

export prj_name=something
mkdir -p $prj_name/{branches,tags,trunk} 
svn import $prj_name file:///opt/svn/repository_name/$prj_name -m "First Import" 
or:
svn import $prj_name https://$svn_host/$svn_repo_path/$prj_name -m "First Import" 

svn+ssh setup

No special setup required on the server side if openssh server is up running. When openssh server is running on non-default port number, client side need to make a change.

either in subversion config: .subversion/config:

[tunnels] sshtunnel = ssh -p 12345
or in ssh config: .ssh/config:

Host teckoo.com User c2 Port 12345

Host 192.168.1.7 HostName another.base.com User c2 Port 12345

Apache Setup

Install package:
```
sudo aptitude install libapache2-svn
```

virtual host config:

 <Location /svn>
     DAV svn

     # All repos subdirs of /opt/svn
     # any "/svn/foo" URL will map to a repository /opt/svn/foo
     SVNParentPath /opt/svn

     # how to authenticate a user
     Require valid-user
     AuthType Basic
     AuthName "Subversion repository"
     AuthUserFile /etc/apache2/dav_svn.passwd
     AuthzSVNAccessFile /opt/svn/.svn-policy-file
     Satisfy Any
 </Location>

To create a user on the repository use, the following command:
```
 sudo htpasswd2 -cm /etc/apache2/dav_svn.passwd <username>
```

If Apache is running by user ‘www-data’, need to allow it to read/write svn repository

sudo adduser www-data dev
sudo chown -R c2:dev /opt/svn/prj_repo
sudo chmod -R g+w /opt/svn/prj_repo

Move a repository

dump data

svnadmin dump /path/to/repository > repository-name.dmp

load data

cd /path/to/new-repository
svnadmin create repository-name
svnadmin load repository-name < repository-name.dmp

Delete a repository

To remove a repository permanently, simplely delete the directory in the file system

rm -rf /opt/svn/$repo

If need to delete some files or directories, simple do

svn delete -m "delete files and directories" http://url/to/your_repo/dir/file

Create a Repository

run the following command from local machine.

svnadmin create /opt/svn/$repo

create/apply a patch

to create a patch: svn diff -r OLD:NEW> my_saving_world_fix.diff
apply a patch: patch -p0 -i my_saving_world_fix.diff -p0 to check all files exist in the folder -i filename specifies the patch file to apply

资源

SVN book - The online manual
Version Control with Subversion by Ben Collins-Sussman, Brian W. Fitzpatrick and C. Michael Pilato
Quick sheet
Subversion Tips for CVS Users
Subclipse - Eclipse plugin

CVS

常用命令 ———— :::console Query the updated the files, and update them $cvs -nq update #not update, just see the changes

update most updated files, including new file/directory, removing sticky_tags
$cvs update -dPA 

List projects in a repository: 
cvs -d :ext:c2@oberon.cis.teckoo.com:/usa/c2/usb_c2/cvsroot rls

Tags 简单应用

All major releases should be tagged:

cvs tag -b tag-name

To retrieve a tagged version, update your repository by doing:

cvs update -r tag-name

to switch to the branch, or to switch to the trunk:

cvs update -A"