1.git：查看系统有没有安装Git
- 安装完成后，在开始菜单里找到“Git”->“Git Bash”，蹦出一个类似命令行窗口的东西，就说明Git安装成功！
2.设置全局属性，用户名和邮箱
$git config --global user.name "qiansao"
$git config --global user.email "1120845268@qq.com"
3. git init：创建版本库
$git init
Initialized empty Git repository in D:/learngit/.git/
4. git add hello.txt：将文件添加到临时区
git add hello.txt
5.git commit -m “create hello.txt file”：把文件提交到仓库
$git commit -m "creat hello.txt file"
[master (root-commit) f5480f5] creat hello.txt file
1 file changed, 1 insertion(+)
create mode 100644 hello.txt
6.git status：查看当前的Git仓库状态
$git status
On branch master
nothing to commit, working tree clean
7.git log：查看从近到远的提交日志
git log
commit 83018ce8b3dc082cd5e5a25c42351afa1e792c26 (HEAD -> master)
Author: qiansao <1120845268@qq.com>
Date: Mon Sep 17 08:56:52 2018 +0800
add a new line
commit f5480f520dad0a7e084cfe8a93e8782876805d00
Author: qiansao <1120845268@qq.com>
Date: Mon Sep 17 08:54:44 2018 +0800
creat hello.txt file
8.git reset --hard commit_id：退回到某一版本
$git reset --hard f5480
HEAD is now at f5480f5 creat hello.txt file
9.git diff：查看文件修改内容
10.git log --pretty=online：简略日志
11.git reflog：查看命令历史
83018ce (HEAD -> master) HEAD@{0}: reset: moving to 83018ce
f5480f5 HEAD@{1}: reset: moving to f5480f5
83018ce (HEAD -> master) HEAD@{2}: reset: moving to 83018
f5480f5 HEAD@{3}: reset: moving to f5480f520dad0a7e084cfe8a93e8782876805d00
83018ce (HEAD -> master) HEAD@{4}: commit: add a new line
f5480f5 HEAD@{5}: commit (initial): creat hello.txt file
12git reset --hard HEAD：退回到上一版本
