Git操作流程：（一）库的创建与文件的增删改查

1、注册

安装完成后，在开始菜单里找到“Git”->“Git Bash”

$ git config --global user.name "Your Name"
$ git config --global user.email "email@example.com"

git config命令的--global参数，用了这个参数，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。

2、创建版本库并提交文件

$ mkdir learngit       //确保目录名（包括父目录）不包含中文
$ cd learngit
$ pwd                //显示当前目录
/Users/michael/learngit
$ git init                   //创建
Initialized empty Git repository in /Users/michael/learngit/.git/             //如果你没有看到.git目录，那是因为这个目录默认是隐藏的，用ls -ah命令就可以看见

$ git add readme.txt       //第一步，用命令git add告诉Git，把文件添加到仓库
$ git commit -m "wrote a readme file"        //第二步，用命令git commit告诉Git，把文件提交到仓库
[master (root-commit) eaadf4e] wrote a readme file
 1 file changed, 2 insertions(+)
 create mode 100644 readme.txt

3、修改文件

$ git status                   //查看结果
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")           //提示readme.txt被修改过了，但还没有准备提交的修改。

$ git diff readme.txt                    //查看修改的内容
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.

$ git add readme.txt                             
$ git commit -m "add distributed"                        //提交修改
[master e475afc] add distributed
 1 file changed, 1 insertion(+), 1 deletion(-)

4、版本回退

$ git log                           //查看提交日志
commit 1094adb7b9b3807259d8cb349e7df1d4d6477073 (HEAD -> master)
             //版本号
Author: Michael Liao <askxuefeng@gmail.com>
Date:   Fri May 18 21:06:15 2018 +0800

    append GPL

commit e475afc93c209a690c39c13a46716e8fa000c366
Author: Michael Liao <askxuefeng@gmail.com>
Date:   Fri May 18 21:03:36 2018 +0800

    add distributed

commit eaadf4e385e865d25c48e7ca9c8395c3f7dfaef0
Author: Michael Liao <askxuefeng@gmail.com>
Date:   Fri May 18 20:59:18 2018 +0800

    wrote a readme file

$ git reset --hard HEAD^                     //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
HEAD is now at e475afc add distributed

$ git reset --hard 1094a                        //回到未来
HEAD is now at 83b0afe append GPL

$ git reflog                                      //记录你的每一次命令
e475afc HEAD@{1}: reset: moving to HEAD^
1094adb (HEAD -> master) HEAD@{2}: commit: append GPL
e475afc HEAD@{3}: commit: add distributed
eaadf4e HEAD@{4}: commit (initial): wrote a readme file

$ git diff HEAD -- readme.txt                   //git diff HEAD -- readme.txt命令可以查看工作区和版本库里面最新版本的区别
diff --git a/readme.txt b/readme.txt
index 76d770f..a9c5755 100644
--- a/readme.txt
+++ b/readme.txt
@@ -1,4 +1,4 @@
 Git is a distributed version control system.
 Git is free software distributed under the GPL.
 Git has a mutable index called stage.
-Git tracks changes.
+Git tracks changes of files.

5、撤销修改和删除文件

git checkout -- readme.txt //让这个文件回到最近一次git commit或git add时的状态，可以丢弃工作区的修改。

$ git reset HEAD readme.txt           //git reset命令既可以回退版本，也可以把暂存区的修改回退到工作区。
Unstaged changes after reset:
M   readme.txt

$ git rm test.txt                //从版本库中删除该文件，那就用命令git rm删掉，并且git commit
rm 'test.txt'

$ git commit -m "remove test.txt"
[master d46f35e] remove test.txt
 1 file changed, 1 deletion(-)
 delete mode 100644 test.txt

$ git checkout -- test.txt             //删错了，因为版本库里还有呢，所以可以很轻松地把误删的文件恢复到最新版本。git checkout其实是用版本库里的版本替换工作区的版本，无论工作区是修改还是删除，都可以“一键还原”。

素材来源：廖雪峰的git教程