从出错中学习Git

17 May 2013
版权声明：本文基于署名 2.5 中国大陆许可协议发布，欢迎转载，演绎或用于商业目的，但是必须保留本文的署名elloop(包含链接)

冲突

丢弃本地的所有修改

- 未commit： git checkout .

- 已经commit： git reset --hard HEAD / git reset --hard HEAD^ (HEAD^是上一个HEAD) 或者 git checkout commit-id

从出错中学习Git

Problem 1

error: object file .git/objects/9a/83e9c5b3d697d12a2e315e1777ceaf27ea1bab is empty
fatal: loose object 9a83e9c5b3d697d12a2e315e1777ceaf27ea1bab (stored in .git/objects/9a/83e9c5b3d697d12a2e315e1777ceaf27ea1bab) is corrupt

solution:

$ rm -fr .git
$ git init
$ git remote add origin your-git-remote-url
$ git fetch
$ git reset --hard origin/master
$ git branch --set-upstream-to=origin/master master

Problem 2

今天忽然git push到github失败，报如下错误, 本地也没有修改git相关配置，一直没使用代理也是好好的，看到github的主页图标改版了，应该是它那边修改了什么，重新安装了Github For Windows也不起作用，尝试了别人说的关闭代理，git config --global --unset http.proxy也没有作用，最后通过切换连接方式解决了问题：HTTPS -> SSH.

fatal: unable to access 'https://github.com/elloop/TankPongPongPong.git/': Failed connect to github.com:443; No error

solution

#查看原来的URLs
git remote -v
#下面的输出是HTTPS
origin  https://github.com/<username>/<reponame>.git (fetch)
origin  https://github.com/<username>/<reponame>.git (push)

# 切换
git remote set-url origin git@github.com:<username>/<reponame>.git

#修改之后，查看是否生效
git remote -v
#看到下面的输出就是修改成SSH了
origin  git@github.com:<username>/<reponame>.git (fetch)
origin  git@github.com:<username>/<reponame>.git (push)

参考链接

submodule 相关命令

1. clone带有submodule的仓库

git clone <url> dir     # clone parent.

cd dir

git submodule init      # register submodules.

git submodule update    # clone submodules. Merge: git submodule init & update.

or, simply: git clone --recursive <url>, recursively clone submoduels.

2. 修改submodule

注意：刚clone下来的submodule，默认不在任何分支上，要想在submodule上工作，最好先checkout出一个新分支，避免在修改之后，因为错误执行git submodule update导致在分支上的修改被覆盖。

cd sub1                 # submodule dir

git checkout master     # switch to master branch

# modifying sub1......

git add .

git commit -m "modify submodule 1"

git push origin master

cd parent-dir

git add -u

git commit -m "update commit id of submodule"

git push origin master

Branch相关命令

从clone说起，git clone ,

  • 查看本地分支:

    git branch

    * master

    clone之后本地只有一个master分支. master自动被创建为跟踪分支(详见下面说明, 它跟踪了origin/master, 使用git remote -v 查看origin的定义).

    本地修改、提交内容之后，执行：

    git push origin master

    会把本地的master分支同步到remote.

  • 查看所有分支

    git branch -a * master remotes/origin/HEAD -> origin/master remotes/origin/develop remotes/origin/master

  • 新建本地分支

git branch "br-name"    # 仅新建，不会切换到新分支
git checkout "br-name"  # 切换到"br-name"分支

或者两句合为一句：

git checkout -b "br-name"   # 新建"br-name"分支，并切换到"br-name"分支

  • 切换(建立)分支：

    git checkout origin/develop Note: checking out ‘origin/develop’.

    You are in ‘detached HEAD’ state. You can look around, make experimental changes and commit them, and you can discard any commits you make in this state without impacting any branches by performing another checkout.

    If you want to create a new branch to retain commits you create, you may do so (now or later) by using -b with the checkout command again. Example:

    git checkout -b new_branch_name

    HEAD is now at 075e05b… update suffix_tree

    正如提示所说，这仅仅是experimental的，就是你可以切到这个临时分支玩一玩，等你checkout到别的分支，在这里的所有提交都会丢失（不影响任何分支）, 要想建立一个本地分支：

    git checkout -b local_develop

    Switched to a new branch ‘local_develop’

  • 跟踪远程分支

    从远程分支 checkout 出来的本地分支，称为 跟踪分支 (tracking branch)。跟踪分支是一种和某个远程分支有直接联系的本地分支。在跟踪分支里输入 git push，Git 会自行推断应该向哪个服务器的哪个分支推送数据。同样，在这些分支里运行 git pull 会获取所有远程索引，并把它们的数据都合并到本地分支中来。

    在克隆仓库时，Git 通常会自动创建一个名为 master 的分支来跟踪 origin/master。这正是 git push 和 git pull 一开始就能正常工作的原因。当然，你可以随心所欲地设定为其它跟踪分支，比如 origin 上除了 master 之外的其它分支。刚才我们已经看到了这样的一个例子：git checkout -b [分支名] [远程名]/[分支名]。如果你有 1.6.2 以上版本的 Git，还可以用 –track 选项简化：

    git checkout –track origin/develop

    Branch develop set up to track remote branch develop from origin. Switched to a new branch ‘develop’

    要为本地分支设定不同于远程分支的名字，只需在第一个版本的命令里换个名字：

    git checkout -b dev origin/develop

    Branch dev set up to track remote branch develop from origin. Switched to a new branch ‘dev’

    现在你的本地分支 dev 会自动将推送和抓取数据的位置定位到 origin/develop 了。

  • 推送到远程分支

    本地的visual-studio 分支推送到远程仓库，新建了一个远程分支

    git push origin visual-studio:visual-studio

    Total 0 (delta 0), reused 0 (delta 0) To https://github.com/elloop/TotalSTL.git

    • [new branch] visual-studio -> visual-studio

  • 删除远程分支

    手误创建了一个origin/visual-studio远程分支，现在想把它删掉

    git push origin :origin/visual-studio

    To https://github.com/elloop/TotalSTL.git

    • [deleted] origin/visual-studio

    linadeMacBook-Pro:TotalSTL lina$

  • 使用某分支(如：develop)直接覆盖另一分支(如：master) git push origin develop:master -f

其他使用Git中遇到的问题

how to stage deleted files?

git add -u

or

try to enter sub-system of git add by typing : git add -i and following the prompt.

git pull conflict

solve:

  1. git stash (solve: commit your changes or stash them before you can merge)
  2. git pull
  3. git stash pop [stash@{0}]
  4. git add (sovle: 'commit' is not possible because you have unmerged files)
  5. git commit

difference between git pull and git fetch

solve:

  • git pull == git fetch && git merge

Useful Command

  1. git log –pretty=oneline

  2. git remote show [remote-name]

  3. git branch

    -no params: show all branches.

    -v: show recently records.

    -merged/-no-merged: show those branches which has been merged or (not merged) to current branch.

oh-my-zsh默认的git命令别名

g=git
ga='git add'
gaa='git add --all'
gapa='git add --patch'
gb='git branch'
gba='git branch -a'
gbda='git branch --merged | command grep -vE "^(\*|\s*master\s*$)" | command xargs -n 1 git branch -d'
gbl='git blame -b -w'
gbnm='git branch --no-merged'
gbr='git branch --remote'
gbs='git bisect'
gbsb='git bisect bad'
gbsg='git bisect good'
gbsr='git bisect reset'
gbss='git bisect start'
gc='git commit -v'
'gc!'='git commit -v --amend'
gca='git commit -v -a'
'gca!'='git commit -v -a --amend'
gcam='git commit -a -m'
'gcan!'='git commit -v -a -s --no-edit --amend'
gcb='git checkout -b'
gcf='git config --list'
gcl='git clone --recursive'
gclean='git clean -fd'
gcm='git checkout master'
gcmsg='git commit -m'
gco='git checkout'
gcount='git shortlog -sn'
gcp='git cherry-pick'
gcs='git commit -S'
gd='git diff'
gdca='git diff --cached'
gdct='git describe --tags `git rev-list --tags --max-count=1`'
gdt='git diff-tree --no-commit-id --name-only -r'
gdw='git diff --word-diff'
gf='git fetch'
gfa='git fetch --all --prune'
gfo='git fetch origin'
gg='git gui citool'
gga='git gui citool --amend'
ggpull='git pull origin $(git_current_branch)'
ggpur=ggu
ggpush='git push origin $(git_current_branch)'
ggsup='git branch --set-upstream-to=origin/$(git_current_branch)'
gignore='git update-index --assume-unchanged'
gignored='git ls-files -v | grep "^[[:lower:]]"'
git-svn-dcommit-push='git svn dcommit && git push github master:svntrunk'
gk='\gitk --all --branches'
gke='\gitk --all $(git log -g --pretty=format:%h)'
gl='git pull'
glg='git log --stat --color'
glgg='git log --graph --color'
glgga='git log --graph --decorate --all'
glgm='git log --graph --max-count=10'
glgp='git log --stat --color -p'
glo='git log --oneline --decorate --color'
globurl='noglob urlglobber '
glog='git log --oneline --decorate --color --graph'
glol='git log --graph --pretty=format:'\''%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset'\'' --abbrev-commit'
glola='git log --graph --pretty=format:'\''%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset'\'' --abbrev-commit --all'
glp=_git_log_prettily
glum='git pull upstream master'
gm='git merge'
gmom='git merge origin/master'
gmt='git mergetool --no-prompt'
gmtvim='git mergetool --no-prompt --tool=vimdiff'
gmum='git merge upstream/master'
gp='git push'
gpd='git push --dry-run'
gpoat='git push origin --all && git push origin --tags'
gpristine='git reset --hard && git clean -dfx'
gpu='git push upstream'
gpv='git push -v'
gr='git remote'
gra='git remote add'
grb='git rebase'
grba='git rebase --abort'
grbc='git rebase --continue'
grbi='git rebase -i'
grbm='git rebase master'
grbs='git rebase --skip'
grep='grep  --color=auto --exclude-dir={.bzr,CVS,.git,.hg,.svn}'
grh='git reset HEAD'
grhh='git reset HEAD --hard'
grmv='git remote rename'
grrm='git remote remove'
grset='git remote set-url'
grt='cd $(git rev-parse --show-toplevel || echo ".")'
gru='git reset --'
grup='git remote update'
grv='git remote -v'
gsb='git status -sb'
gsd='git svn dcommit'
gsi='git submodule init'
gsps='git show --pretty=short --show-signature'
gsr='git svn rebase'
gss='git status -s'
gst='git status'
gsta='git stash'
gstaa='git stash apply'
gstd='git stash drop'
gstl='git stash list'
gstp='git stash pop'
gsts='git stash show --text'
gsu='git submodule update'
gts='git tag -s'
gtv='git tag | sort -V'
gunignore='git update-index --no-assume-unchanged'
gunwip='git log -n 1 | grep -q -c "\-\-wip\-\-" && git reset HEAD~1'
gup='git pull --rebase'
gupv='git pull --rebase -v'
gwch='git whatchanged -p --abbrev-commit --pretty=medium'
gwip='git add -A; git rm $(git ls-files --deleted) 2> /dev/null; git commit -m "--wip--"'
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