Git-第二篇廖雪峰Git教程学习笔记（1）基本命令，版本回退

1、安装Git-2.16.2-64-bit.exe后，设置用户名，用户邮箱

#--global参数，表示你这台机器上所有的Git仓库都会使用这个配置，当然也可以对某个仓库指定不同的用户名和Email地址。
$ git config --global user.name "Your Name"
$ git config --global user.email "email@example.com"

2、创建版本库

命令：git init

版本库：版本库又名仓库，英文名repository，你可以简单理解成一个目录，这个目录里面的所有文件都可以被Git管理起来，每个文件的修改、删除，Git都能跟踪，以便任何时刻都可以追踪历史，或者在将来某个时刻可以“还原”。

3、把文件添加到版本库

命令：git add 文件

解析：将文件添加到暂存区

命令：git commit -m "log description"

解析：将文件添加到本地库。-m命令用于添加提交说明日志。

命令：git status

解析：查看当前的文件修改状态。上面截图因为我们已经提交到本地仓库了，所以当前库中没有任何修改。

命令：git diff 文件

解析：查看指定文件差异。

lfy@lfy-PC MINGW64 /c/fyliu/lfyTemp/gitLocalRepository/yangjie (master)
$ 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")

lfy@lfy-PC MINGW64 /c/fyliu/lfyTemp/gitLocalRepository/yangjie (master)
$ git diff readme.txt
warning: LF will be replaced by CRLF in readme.txt.
The file will have its original line endings in your working directory.
diff --git a/readme.txt b/readme.txt
index 9c69c9c..4b1c78e
--- a/readme.txt
+++ b/readme.txt
@@ -, +, @@
-GIt is a version control system.
+GIt is a distributed version control system.
 Git is free software.

lfy@lfy-PC MINGW64 /c/fyliu/lfyTemp/gitLocalRepository/yangjie (master)
$

4、版本回退

命令：git log [--pretty=oneline]

解析：显示从最近到最远的提交日志

lfy@lfy-PC MINGW64 /c/fyliu/lfyTemp/gitLocalRepository/yangjie (master)
$ git log
commit adde96d057448c792343465df3aee108764defbd (HEAD -> master)
Author: lfy <@qq.com>
Date:   Sat Aug  ::  +

    add GPL

commit 31728b8d6ec5a40ed7eca72aca63533d8625b423
Author: lfy <@qq.com>
Date:   Sat Aug  ::  +

    add distributed

commit 586474b5bd16e377df3b657ffc1b35f663a69038
Author: lfy <@qq.com>
Date:   Sat Aug  ::  +

    create readme.txt

在Git中，用HEAD表示当前版本，上一个版本就是HEAD^，上上一个版本就是HEAD^^，当然往上100个版本写100个^比较容易数不过来，所以写成HEAD~100。

  现在，我们要把当前版本append GPL回退到上一个版本add distributed，就可以使用git reset命令

命令：git reset --hard commit_id

解析：

lfy@lfy-PC MINGW64 /c/fyliu/lfyTemp/gitLocalRepository/yangjie (master)
$ git reset --hard HEAD^
HEAD is now at 31728b8 add distributed

再次查看log，发现我们最后一次提交的内容已经找不到了。但是，只要当前窗口没有关闭（或者关闭了但你要记得commit id），还是可以再找回的，要输入之前查看的commit id。（即adde96d057...）

lfy@lfy-PC MINGW64 /c/fyliu/lfyTemp/gitLocalRepository/yangjie (master)
$ git log
commit 31728b8d6ec5a40ed7eca72aca63533d8625b423 (HEAD -> master)
Author: lfy <@qq.com>
Date:   Sat Aug  ::  +

    add distributed

commit 586474b5bd16e377df3b657ffc1b35f663a69038
Author: lfy <@qq.com>
Date:   Sat Aug  ::  +

    create readme.txt

lfy@lfy-PC MINGW64 /c/fyliu/lfyTemp/gitLocalRepository/yangjie (master)
$ git reset --hard adde96
HEAD is now at adde96d add GPL

lfy@lfy-PC MINGW64 /c/fyliu/lfyTemp/gitLocalRepository/yangjie (master)
$ cat readme.txt
GIt is a distributed version control system.
Git is free software distributed under the GPL.

lfy@lfy-PC MINGW64 /c/fyliu/lfyTemp/gitLocalRepository/yangjie (master)
$ git log
commit adde96d057448c792343465df3aee108764defbd (HEAD -> master)
Author: lfy <1220429263@qq.com>
Date:   Sat Aug 24 21:08:03 2019 +0800

    add GPL

commit 31728b8d6ec5a40ed7eca72aca63533d8625b423
Author: lfy <@qq.com>
Date:   Sat Aug  ::  +

    add distributed

commit 586474b5bd16e377df3b657ffc1b35f663a69038
Author: lfy <@qq.com>
Date:   Sat Aug  ::  +

    create readme.txt

lfy@lfy-PC MINGW64 /c/fyliu/lfyTemp/gitLocalRepository/yangjie (master)
$

命令：git reflog

解析：记录你的命令

lfy@lfy-PC MINGW64 /c/fyliu/lfyTemp/gitLocalRepository/yangjie (master)
$ git reflog
adde96d (HEAD -> master) HEAD@{}: reset: moving to adde96
31728b8 HEAD@{}: reset: moving to HEAD^
adde96d (HEAD -> master) HEAD@{}: commit: add GPL
31728b8 HEAD@{}: commit: add distributed
586474b HEAD@{}: commit (initial): create readme.txt

lfy@lfy-PC MINGW64 /c/fyliu/lfyTemp/gitLocalRepository/yangjie (master)
$