Git教程(超级详细)

一、安装Git

Windows
直接在官网上下载

Linux
centOS：

$ yum install git

Ubuntu:

$ sudo apt-get install git

安装后需要设置下

$ git config --global user.name "Your Name"
$ git config --global user.email "[e-mail]"

二、创建仓库(repository)

创建目录

$ mkdir git_test
$ cd git_test/

初始化仓库

$ git init
Initialized empty Git repository in /home/dgut/git_test/.git/

这里我目录的位置是/home/dgut/git_test/

在git_test目录下编写readme.txt文件，尝试把文件放入到git仓库中

$ vim readme.txt 

文件内容为：

Git is a distributed version control system.
Git is free software.

第一步：把文件添加到暂存区中

$ git add readme.txt

第二步：把文件提交到仓库当前分支中

$ git commit -m "commit a readme.txt file"

-m 后面的内容为本次提交的说明

三、修改文件

（有时我们要修改已提交的文件）

修改完文件后用 git status 命令查看结果

$ git status
On branch master
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

	modified:   readme.txt

no changes added to commit (use "git add" and/or "git commit -a")

还可以使用 git diff readme.txt 命令具体修改的内容

$ git diff readme.txt 
diff --git a/readme.txt b/readme.txt
index 46d49bf..9247db6 100644
--- a/readme.txt
+++ b/readme.txt
@@ -1,2 +1,2 @@
-Git is a version control system.
+Git is a distributed version control system.
 Git is free software.

把修改后的文件再次提交

$ git add readme.txt
$ git commit -m "modified readme.txt"
[master e475afc] modified readme.txt
 1 file changed, 1 insertion(+), 1 deletion(-)

四、版本查看和版本回退

刚刚我们修改了两次readme.txt，一次有两次版本
版本1：commit a file
版本2：modified readme.txt
使用 git log 命令可以查看我们各次提交的信息

$ git log
commit 82f64ce7fcc19b4768c827e15e76e4274b4c8f8b
Author: Ruifengs <[e-mail]>
Date:   Tue Jun 2 10:45:42 2020 +0800

    modified readme.txt

commit 8fe95a336daf3a2aa5fed444ce35c941045711e5
Author: Ruifengs <[e-mail]>
Date:   Tue Jun 2 10:24:13 2020 +0800

    commit a file

还有一个让输出更简洁的命令 git log --pretty=oneline

$ git log --pretty=oneline
82f64ce7fcc19b4768c827e15e76e4274b4c8f8b modified readme.txt
8fe95a336daf3a2aa5fed444ce35c941045711e5 commit a file

有时我们发现修改后的版本不满意，使用 git reset 命令可以回退到上一个版本 。
HEAD表示当前版本；上一个版本就是HEAD^；上上一个版本就是HEAD^^，版本过多的话，写很多个^有点不现实，比如往上50个版本的话，可以写成HEAD~50。

$ git reset --hard HEAD^
HEAD is now at 8fe95a3 commit a file

查看下现在仓库的状态,可以看到已经回到第一个版本

$ git log
commit 8fe95a336daf3a2aa5fed444ce35c941045711e5
Author: Ruifengs <[e-mail]>
Date:   Tue Jun 2 10:24:13 2020 +0800

    commit a file

git要回到某一版本还可以指定版本号恢复,版本号写前几位便可，现在我们试着回到第二个版本——modified readme.txt

$ git reset --hard 82f64ce
HEAD 现在位于 82f64ce modified readme.txt

git还提供了查看历史操作的命令

$ git reflog
82f64ce [e-mail]{0}: reset: moving to 82f64ce
8fe95a3 [e-mail]{1}: reset: moving to HEAD^
82f64ce [e-mail]{2}: commit: modified readme.txt
8fe95a3 [e-mail]{3}: commit (initial): commit a file

五、撤销修改

工作区撤销：当你改乱了工作区某个文件的内容，想直接丢弃工作区的修改时，用命令git checkout – 下面试一下:

# 一开始readme.txt内容如下
$ cat readme.txt 
Git is a distributed version control system.
Git is free software.

# 修改后的readme.txt文件内容
$ cat readme.txt 
Git is a distributed version control system.
Git is free software.
Error

# 使用 git checkout -- readme.txt 撤回修改
$ git checkout -- readme.txt

# 再次查看readme.txt文件内容,可以发现已经撤回到原来的样子
$ cat readme.txt 
Git is a distributed version control system.
Git is free software.

暂存区撤销：当你不但改乱了工作区某个文件的内容，还添加到了暂存区时，想丢弃修改，分两步，第一步用命令git reset HEAD ，第二步用 git checkout –
例子如下：

# 原文件内容
$ cat readme.txt 
Git is a distributed version control system.
Git is free software.

# 修改后内容如下，并提交到暂存区
$ cat readme.txt 
Git is a distributed version control system.
Git is free software.
Error
$ git add readme.txt
# 查看下仓库状态
$ git status
On branch master
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)

	modified:   readme.txt

no changes added to commit (use "git add" and/or "git commit -a")

# 当提交后你后悔了，想让内容恢复到原来的样子，需要输入以下命令
$ git reset HEAD readme.txt
Unstaged changes after reset:
M	readme.txt
$ git checkout -- readme.txt

# 查看结果,发现已经撤回到原来的样子
$ cat readme.txt
Git is a distributed version control system.
Git is free software.

版本库撤销：如果已经提交了不合适的修改到版本库时，想要撤销本次提交，可以参考第四节版本查看和版本回退

六、删除文件

# 提交一个测试文件
$ git add delete_test
$ git commit -m "delete"
[master 02d3fc2] delete
 1 file changed, 1 insertion(+)
 create mode 100644 delete_test
 
 # 第一步：本地手动删除文件
 $ rm -f delete_test
 
# 第二步：从版本库删除
$ git rm delete_test
rm 'delete_test'

# 第三步：提交到版本库
$  git commit -m "delete file"
[master 519fbc0] delete file
 1 file changed, 1 deletion(-)
 delete mode 100644 delete_test

七、添加远程库和克隆仓库

登录github，创建新的Repository

在本地进入到目录下，然后运行命令 git remote add origin ‘你远程仓库的地址’ 表示连接到你的远程仓库(通过ssh连接加密)，此处略写，可以参照：https://www.runoob.com/git/git-remote-repo.html

$ cd /home/badou/git_test/first_repository
$ git remote add origin [e-mail]:Ruifengs/create_test.git

然后通过 git push -u origin master 命令把本地库的所有内容推送到远程库上，-u参数的作用是关联本地的master分支和远程的master分支，这个参数只需在第一次推送时加，往后的push只需运行命令：git push origin master

$ git push -u origin master
Counting objects: 20, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (15/15), done.
Writing objects: 100% (20/20), 1.64 KiB | 560.00 KiB/s, done.
Total 20 (delta 5), reused 0 (delta 0)
remote: Resolving deltas: 100% (5/5), done.
To github.com:michaelliao/learngit.git
 * [new branch]      master -> master
Branch 'master' set up to track remote branch 'master' from 'origin'.

git clone 要克隆的仓库地址 命令可以从远程仓库中克隆一个repository

$ git clone [e-mail]:Ruifengs/Spring-test.git
Cloning into 'gitskills'...
remote: Counting objects: 3, done.
remote: Total 3 (delta 0), reused 0 (delta 0), pack-reused 3
Receiving objects: 100% (3/3), done.

八、分支管理

1.创建与分支管理

创建dev分支，然后切换到dev分支， -b参数表示创建并切换，有两种命令可以实现操作，建议使用第二种。

$ git checkout -b dev
Switched to a new branch 'dev'

$ git switch -c dev
Switched to a new branch 'dev'

git branch命令可以查看所有分支，*号表示分支。

$ git branch
* dev
  master

试着在dev分支上修改readme.txt文件并提交。

# 在readme.txt加上
I'm test modify

$ cat readme.txt 
Git is a distributed version control system.
Git is free software.
I'm test modify

# 提交
$ git add readme.txt
$ git commit -m "in dev modify"
[dev 73a458a] in dev modify
1 file changed, 1 insertion(+)

# 回到master分支上
$ git checkout master
Switched to branch 'master'

# 查看readme.txt会发现刚刚加上的句子消失了，原因就是刚刚是在dev分支上修改
# master分支此刻的提交点并没有变
$ cat readme.txt 
Git is a distributed version control system.
Git is free software.

# 因此我们需要把dev分支合并到master分支
$ $ git merge dev
Updating d46f35e..b17d20e
Fast-forward
 readme.txt | 1 +
 1 file changed, 1 insertion(+)
 
 # 查看readme.txt，
$ cat readme.txt 
Git is a distributed version control system.
Git is free software.
I'm test modify

合并完分支后就可以把分支删除了，命令：git branch -d <name> 注意：如果要强行删除未合并的分支 命令为：git branch -D <name>

$ git branch -d dev
Deleted branch dev（was 73a458a）

切换分支有两种命令方式，建议使用第二种
git checkout <name>或者git switch <name>

2、Bug分支

应用场景：有时我们正在dev分支进行一个工作时，突然收到一个修复bug的紧急任务，而我们手上的工作又还没做完，还无法提交，这时候我们可以先把工作区的工作“保存起来”，新建一个分支来处理bug，之后再回到dev分支，恢复之前的工作现场.。

# git status 可以看到现在在dev分支
$ git status
# On branch dev
# Changes not staged for commit:
#   (use "git add <file>..." to update what will be committed)
#   (use "git checkout -- <file>..." to discard changes in working directory)
#
#	modified:   readme.txt
#
no changes added to commit (use "git add" and/or "git commit -a")

# git stash 命令把工作区的保存起来
$ git stash
Saved working directory and index state WIP on dev: 7e97564 modify
HEAD is now at 7e97564 modify

# git stash list 命令可以查看stash里被保存的分支，可以看到dev已经在里面
$ git stash list
[e-mail]{0}: WIP on dev: 7e97564 modify

# 工作区也已经没有任务
$ git status
On branch dev
nothing to commit, working directory clean

# 现在开始进行修复bug，假设要修复的bug是在readme.txt添加"This is a bug!"

# 先回到master主支
$ git checkout master
Switched to branch 'master'

# 创建bug分支并切换
$ git checkout -b bug
Switched to a new branch 'bug'

# 本地修改完readme.txt提交到版本库
$ git add readme.txt
$ git commit -m "bug over"
[bug cf35c20] bug over
 1 file changed, 1 insertion(+), 1 deletion(-)
 
# 提交后切换到master,把bug分支合并到master主支
$ git checkout master
Switched to branch 'master'
$ git merge bug
Updating caa245d..c               f35c20
Fast-forward
 readme.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

# 然后删掉bug分支
$ git branch -d bug
Deleted branch bug (was cf35c20).

# 回到dev分支,继续做我们的工作
$ git checkout dev
Switched to branch 'dev'

# 查看工作区,发现目前是空的
$ git status
# On branch dev
nothing to commit, working directory clean

# 现在运行 git stash apply 命令把stash的内容恢复到工作区
$ git stash apply
# On branch dev
# Changes not staged for commit:
#   (use "git add <file>..." to update what will be committed)
#   (use "git checkout -- <file>..." to discard changes in working directory)
#
#	modified:   readme.txt
#
no changes added to commit (use "git add" and/or "git commit -a")

# 恢复后需要把stash清理掉 运行 git stash drop 命令.
# 或者 直接运行 git stash pop 恢复内容的同时把stash内容也删了
$ git stash drop
Dropped refs/[e-mail]{0} (882631f33554c87b756faa489d05ee957330920a)

3、冲突解决

情景：有a、b同学，共同开发一个项目，a同学、b同学同时把项目克隆到本地，a同学在readme.txt文件添加了一句话"I’m a"，提交到本地库后，push到远程仓库；另一边，b同学同样对readme.txt修改，添加了一句"I’m b’"，然后提交，当要push到远程仓库后报错。这是因为a同学最新提交和b同学试图推送的提交有冲突，要先解决冲突才能push成功。例子如下：

# a 同学

# 修改后添加到暂存区，提交 
$ $ git add readme.txt
$ git commit -m "add a"
[dev 84d2900] add a
 1 file changed, 1 insertion(+)

# push到远程仓库
$ git push origin dev
Counting objects: 5, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (3/3), 265 bytes | 0 bytes/s, done.
Total 3 (delta 1), reused 0 (delta 0)
remote: Resolving deltas: 100% (1/1), completed with 1 local object.
To [e-mail]:Ruifengs/create_test.git
   246bdf7..84d2900  dev -> dev      

# b同学

# 修改后添加到暂存区，提交 
$ git add readme.txt
$ git commit -m "add b"
[dev 84d2900] add b
 1 file changed, 1 insertion(+)
 
 # 在push的时候出出错了，提示我们需要先把远程库的内容pull下来，手动合并后再push
$ git push origin dev
To [e-mail]:Ruifengs/create_test.git
 ! [rejected]        dev -> dev (fetch first)
error: failed to push some refs to '[e-mail]:Ruifengs/create_test.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 merge the remote changes (e.g.,
hint: 'git pull') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

# pull dev分支的内容到本地，但是最后提示merge失败，是因为冲突还没有解决。
$ git pull origin dev
remote: Enumerating objects: 5, done.
remote: Counting objects: 100% (5/5), done.
remote: Compressing objects: 100% (1/1), done.
remote: Total 3 (delta 1), reused 3 (delta 1), pack-reused 0
Unpacking objects: 100% (3/3), done.
From github.com:Ruifengs/create_test
 * branch            dev        -> FETCH_HEAD
Auto-merging readme.txt
CONFLICT (content): Merge conflict in readme.txt
Automatic merge failed; fix conflicts and then commit the result.

# 修改readme.txt手动合并内容
$ vim readme.txt

# 提交到版本库
$ git add readme.txt 
$ git commit -m "combine a and b"
[dev 6403c29] combine a and b

# 再次提交就成功啦
$ git push origin dev
Counting objects: 10, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (4/4), done.
Writing objects: 100% (6/6), 507 bytes | 0 bytes/s, done.
Total 6 (delta 2), reused 0 (delta 0)
remote: Resolving deltas: 100% (2/2), completed with 1 local object.
To [e-mail]:Ruifengs/create_test.git
   84d2900..6403c29  dev -> dev

4、标签管理

# 创建标签，默认标签是打在最新提交的commit上，也就是HEAD
$ git tag v2.0

# 查看所有标签
$ git tag
v2.0

# git show <tagname>
$ git show v2.0
commit 69b25eb9ed9cb3feb530b8faa1eee0e00309ebfa
Author: Ruifengs <[e-mail]>
Date:   Thu Jun 4 10:06:18 2020 +0800

    add words

diff --git a/readme.txt b/readme.txt
index 9247db6..6b3d2c4 100644
--- a/readme.txt
+++ b/readme.txt
@@ -1,2 +1,3 @@
 Git is a distributed version control system.
 Git is free software.
+Hello,I'm secone_test

# 还可以创建带有说明的标签，用-a指定标签名，-m指定说明文字
$ git tag -a v0.1 -m "version 0.1 released" 519fbc0
$ git show v0.1
tag v0.1
Tagger: Ruifengs <[e-mail]>
Date:   Thu Jun 4 13:43:39 2020 +0800

version 0.1 released

commit 519fbc0d4fc428415622d8cff7a5bbf49d4cd006
Author: Ruifengs <[e-mail]>
Date:   Tue Jun 2 13:28:45 2020 +0800

    delete file

diff --git a/delete_test b/delete_test
deleted file mode 100644
index 47b0484..0000000
--- a/delete_test
+++ /dev/null
@@ -1 +0,0 @@
-wawa

# 删除本地标签
$ git tag -d v2.0
Deleted tag 'v2.0' (was 69b25eb)

# 如果要删除远程标签，先删除本地标签，再运行下面命令
$ git push origin :refs/tags/v9.0

# 推送某个本地标签到远程仓库
$ git push origin v9.0
Total 0 (delta 0), reused 0 (delta 0)
To [e-mail]:Ruifengs/create_test.git
 * [new tag]         v9.0 -> v9.0
 
# 一次性推送所有标签到远程库
$ git push origin --tags
Counting objects: 1, done.
Writing objects: 100% (1/1), 166 bytes | 0 bytes/s, done.
Total 1 (delta 0), reused 0 (delta 0)
To [e-mail]:Ruifengs/create_test.git
 * [new tag]         2.0 -> 2.0
 * [new tag]         v0.1 -> v0.1

reference：https://www.liaoxuefeng.com/wiki/896043488029600