当你从远程仓库克隆时,实际上Git自动把本地的master分支和远程的master分支对应起来了,并且,远程仓库的默认名称是origin。
要查看远程库的信息,用git remote:
$ git remote origin
或者,用git remote -v显示更详细的信息:
$ git remote -v origin [email protected] */" _ue_custom_node_="true">:michaelliao/learngit.git (fetch) origin [email protected] */" _ue_custom_node_="true">:michaelliao/learngit.git (push)
上面显示了可以抓取和推送的origin的地址。如果没有推送权限,就看不到push的地址。
推送分支
推送分支,就是把该分支上的所有本地提交推送到远程库。推送时,要指定本地分支,这样,Git就会把该分支推送到远程库对应的远程分支上:
$ git push origin master
如果要推送其他分支,比如dev,就改成:
$ git push origin dev
但是,并不是一定要把本地分支往远程推送,那么,哪些分支需要推送,哪些不需要呢?
master分支是主分支,因此要时刻与远程同步;
dev分支是开发分支,团队所有成员都需要在上面工作,所以也需要与远程同步;
bug分支只用于在本地修复bug,就没必要推到远程了,除非老板要看看你每周到底修复了几个bug;
feature分支是否推到远程,取决于你是否和你的小伙伴合作在上面开发。
总之,就是在Git中,分支完全可以在本地自己藏着玩,是否推送,视你的心情而定!
抓取分支
多人协作时,大家都会往master和dev分支上推送各自的修改。
现在,模拟一个你的小伙伴,可以在另一台电脑(注意要把SSH Key添加到GitHub)或者同一台电脑的另一个目录下克隆:
$ git clone [email protected] */" _ue_custom_node_="true">:michaelliao/learngit.git Cloning into 'learngit'... remote: Counting objects: 46, done. remote: Compressing objects: 100% (26/26), done. remote: Total 46 (delta 16), reused 45 (delta 15) Receiving objects: 100% (46/46), 15.69 KiB | 6 KiB/s, done. Resolving deltas: 100% (16/16), done.
当你的小伙伴从远程库clone时,默认情况下,你的小伙伴只能看到本地的master分支。不信可以用git branch命令看看:
$ git branch * master
现在,你的小伙伴要在dev分支上开发,就必须创建远程origin的dev分支到本地,于是他用这个命令创建本地dev分支:
$ git checkout -b dev origin/dev
现在,他就可以在dev上继续修改,然后,时不时地把dev分支push到远程:
$ git commit -m "add /usr/bin/env" [dev 291bea8] add /usr/bin/env 1 file changed, 1 insertion(+) $ git push origin dev Counting objects: 5, done. Delta compression using up to 4 threads. Compressing objects: 100% (2/2), done. Writing objects: 100% (3/3), 349 bytes, done. Total 3 (delta 0), reused 0 (delta 0) To [email protected] */" _ue_custom_node_="true">:michaelliao/learngit.git fc38031..291bea8 dev -> dev
你的小伙伴已经向origin/dev分支推送了他的提交,而碰巧你也对同样的文件作了修改,并试图推送:
$ git add hello.py $ git commit -m "add coding: utf-8"[dev bd6ae48] add coding: utf-8 1 file changed, 1 insertion(+) $ git push origin devTo [email protected] */" _ue_custom_node_="true">:michaelliao/learngit.git ! [rejected] dev -> dev (non-fast-forward) error: failed to push some refs to '[email protected] */" _ue_custom_node_="true">:michaelliao/learngit.git' hint: Updates were rejected because the tip of your current branch is behind hint: its remote counterpart. Merge the remote changes (e.g. 'git pull') hint: before pushing again. hint: See the 'Note about fast-forwards' in 'git push --help' for details.
推送失败,因为你的小伙伴的最新提交和你试图推送的提交有冲突,解决办法也很简单,Git已经提示我们,先用git pull把最新的提交从origin/dev抓下来,然后,在本地合并,解决冲突,再推送:
$ git pull remote: Counting objects: 5, done. remote: Compressing objects: 100% (2/2), done. remote: Total 3 (delta 0), reused 3 (delta 0) Unpacking objects: 100% (3/3), done. From github.com:michaelliao/learngit fc38031..291bea8 dev -> origin/dev There is no tracking information for the current branch. Please specify which branch you want to merge with. See git-pull(1) for details git pull If you wish to set tracking information for this branch you can do so with: git branch --set-upstream dev origin/
git pull也失败了,原因是没有指定本地dev分支与远程origin/dev分支的链接,根据提示,设置dev和origin/dev的链接:
$ git branch --set-upstream dev origin/dev Branch dev set up to track remote branch dev from origin.
再pull:
$ git pullAuto-merging hello.py CONFLICT (content): Merge conflict in hello.py Automatic merge failed; fix conflicts and then commit the result.
这回git pull成功,但是合并有冲突,需要手动解决,解决的方法和分支管理中的解决冲突完全一样。解决后,提交,再push:
$ git commit -m "merge & fix hello.py" [dev adca45d] merge & fix hello.py $ git push origin dev Counting objects: 10, done. Delta compression using up to 4 threads. Compressing objects: 100% (5/5), done. Writing objects: 100% (6/6), 747 bytes, done. Total 6 (delta 0), reused 0 (delta 0) To [email protected] */" _ue_custom_node_="true">:michaelliao/learngit.git 291bea8..adca45d dev -> dev
因此,多人协作的工作模式通常是这样:
首先,可以试图用git push origin branch-name推送自己的修改;
如果推送失败,则因为远程分支比你的本地更新,需要先用git pull试图合并;
如果合并有冲突,则解决冲突,并在本地提交;
没有冲突或者解决掉冲突后,再用git push origin branch-name推送就能成功!
如果git pull提示“no tracking information”,则说明本地分支和远程分支的链接关系没有创建,用命令git branch --set-upstream branch-name origin/branch-name。这就是多人协作的工作模式,一旦熟悉了,就非常简单。
小结
查看远程库信息,使用git remote -v;
本地新建的分支如果不推送到远程,对其他人就是不可见的;
从本地推送分支,使用git push origin branch-name,如果推送失败,先用git pull抓取远程的新提交;
在本地创建和远程分支对应的分支,使用git checkout -b branch-name origin/branch-name,本地和远程分支的名称最好一致;
建立本地分支和远程分支的关联,使用git branch --set-upstream branch-name origin/branch-name;
从远程抓取分支,使用git pull,如果有冲突,要先处理冲突。
本文来源:廖雪峰的官方网站(http://www.liaoxuefeng.com)