當你從遠程倉庫克隆時,實際上Git自動把本地的master
分支和遠程的master
分支對應起來了,並且,遠程倉庫的默認名稱是origin
。
要查看遠程庫的信息,用git remote
:
$ git remote
origin
或者,用git remote -v
顯示更詳細的信息:
$ git remote -v
origin [email protected]:nuaazc2011/Git.git (fetch)
origin [email protected]:nuaazc2011/Git.git (push)
上面顯示了可以抓取和推送的origin
的地址。如果沒有推送權限,就看不到push的地址。
推送分支
推送分支,就是把該分支上的所有本地提交推送到遠程庫。推送時,要指定本地分支,這樣,Git就會把該分支推送到遠程庫對應的遠程分支上:
$ 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,並不是一定要把本地分支往遠程推送,那麼,哪些分支需要推送,哪些不需要呢?
master
分支是主分支,因此要時刻與遠程同步;dev
分支是開發分支,團隊所有成員都需要在上面工作,所以也需要與遠程同步;bug分支只用於在本地修復bug,就沒必要推到遠程了,除非老闆要看看你每週到底修復了幾個bug;
feature分支是否推到遠程,取決於你是否和你的小夥伴合作在上面開發。
總之,就是在Git中,分支完全可以在本地自己藏着玩,是否推送,視你的心情而定!
抓取分支
多人協作時,大家都會往master
和dev
分支上推送各自的修改。
現在,模擬一個你的小夥伴,可以在另一臺電腦(注意要把SSH Key添加到GitHub)或者同一臺電腦的另一個目錄下克隆:
$ git clone [email protected]:nuaazc2011/Git.git
Cloning into 'Git'...
remote: Counting objects: 41, done.
remote: Compressing objects: 100% (21/21), done.
remote: Total 41 (delta 15), reused 41 (delta 15), pack-reused 0
Receiving objects: 100% (41/41), done.
Resolving deltas: 100% (15/15), done.
當你的小夥伴從遠程庫clone時,默認情況下,你的小夥伴只能看到本地的master
分支。不信可以用git branch
命令看看:
$ git branch
* master
現在,你的小夥伴要在dev
分支上開發,就必須創建遠程origin
的dev
分支到本地,於是他用這個命令創建本地dev
分支:
$ git checkout -b dev origin/dev
Switched to a new branch 'dev'
Branch 'dev' set up to track remote branch 'dev' from 'origin'.
現在,他就可以在dev
上繼續修改,然後,時不時地把dev
分支push
到遠程:
$ git add env.txt
$ git commit -m "add env"
[dev 9bf267d] add env
1 file changed, 0 insertions(+), 0 deletions(-)
create mode 100644 env.txt
$ git push origin dev
Counting objects: 2, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (2/2), 296 bytes | 98.00 KiB/s, done.
Total 2 (delta 0), reused 0 (delta 0)
To github.com:nuaazc2011/Git.git
384ee10..9bf267d dev -> dev
你的小夥伴已經向origin/dev
分支推送了他的提交,而碰巧你也對同樣的文件作了修改,並試圖推送:
$ cat env.txt
student
$ git add env.txt
warning: LF will be replaced by CRLF in env.txt.
The file will have its original line endings in your working directory.
$ git commit -m "add new env"
[dev 7d0790d] add new env
1 file changed, 1 insertion(+)
create mode 100644 env.txt
$ git push origin dev
To github.com:nuaazc2011/Git.git
! [rejected] dev -> dev (fetch first)
error: failed to push some refs to '[email protected]:nuaazc2011/Git.git'
hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushing
hint: to the same ref. You may want to first integrate the remote changes
hint: (e.g., 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.
推送失敗,因爲你的小夥伴的最新提交和你試圖推送的提交有衝突,解決辦法也很簡單,Git已經提示我們,先用git pull
把最新的提交從origin/dev
抓下來,然後,在本地合併,解決衝突,再推送:
$ git pull
remote: Counting objects: 5, done.
remote: Compressing objects: 100% (3/3), done.
remote: Total 5 (delta 1), reused 5 (delta 1), pack-reused 0
Unpacking objects: 100% (5/5), done.
From github.com:nuaazc2011/Git
384ee10..176f0a7 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 <remote> <branch>
If you wish to set tracking information for this branch you can do so with:
git branch --set-upstream-to=origin/<branch> dev
git pull
也失敗了,原因是沒有指定本地dev
分支與遠程origin/dev
分支的鏈接,根據提示,設置dev
和origin/dev
的鏈接:
$ git branch --set-upstream-to=origin/dev dev
Branch 'dev' set up to track remote branch 'dev' from 'origin'.
再pull:
$ git pull
Auto-merging env.txt
CONFLICT (add/add): Merge conflict in env.txt
Automatic merge failed; fix conflicts and then commit the result.
這回git pull
成功,但是合併有衝突,需要手動解決,解決的方法和前面的解決衝突完全一樣。解決後,提交,再push:
$ git add env.txt
$ git commit -m "fix env conflict"
[dev fe0a2da] fix env conflict
$ git push origin dev
Counting objects: 6, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (4/4), done.
Writing objects: 100% (6/6), 532 bytes | 106.00 KiB/s, done.
Total 6 (delta 2), reused 0 (delta 0)
remote: Resolving deltas: 100% (2/2), completed with 1 local object.
To github.com:nuaazc2011/Git.git
176f0a7..fe0a2da dev -> dev
因此,多人協作的工作模式通常是這樣:
首先,可以試圖用
git push origin <branch-name>
推送自己的修改;如果推送失敗,則因爲遠程分支比你的本地更新,需要先用
git pull
試圖合併;如果合併有衝突,則解決衝突,並在本地提交;
沒有衝突或者解決掉衝突後,再用
git push origin <branch-name>
推送就能成功!
如果git pull
提示no tracking information
,則說明本地分支和遠程分支的鏈接關係沒有創建,用 命 令
git branch --set-upstream-to <branch-name> origin/<branch-name>
。這就是多人協作的工作模式。
小結
查看遠程庫信息,使用
git remote -v
;本地新建的分支如果不推送到遠程,對其他人就是不可見的;
從本地推送分支,使用
git push origin branch-name
,如果推送失敗,先用git pull
抓取遠程的新提交;在本地創建和遠程分支對應的分支,使用
git checkout -b branch-name origin/branch-name
,本地和遠程分支的名稱最好一致;建立本地分支和遠程分支的關聯,使用
git branch --set-upstream branch-name origin/branch-name
;從遠程抓取分支,使用
git pull
,如果有衝突,要先處理衝突。