大話git中的撤銷操做

下面以現實場景做爲情境。

基礎知識，理解git中的幾個區域

本地代碼已經add，未commit

修改本地工做目錄中的readme.md,添加文字"第一次修改"

而後查看下狀態

➜  experimentation git:(master) ✗ git status
On branch master
Your branch is up-to-date with 'origin/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.md

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

進行Add操做,並查看狀態

➜  experimentation git:(master) ✗ git add README.md
➜  experimentation git:(master) ✗ git status
On branch master
Your branch is up-to-date with 'origin/master'.
Changes to be committed:
  (use "git reset HEAD <file>..." to unstage)

        modified:   README.md

➜  experimentation git:(master) ✗

這時候，變更進入了緩存區(Index)

可是咱們忽然發現咱們改動錯了，其實我是想改動experimentation.txt文件。

方法一：咱們固然能夠再次修改experimentation和readme文件（刪除readme中的修改，給experimentation中添加「第一次修改」），而後再Add

方法二：咱們想的多是撤回以前的add操做，而後給experimentation中添加「第一次修改」，而後再次Add,那這樣的話，咱們如何操做呢？

• 撤銷某個add文件:git reset HEAD <filename>

• 撤銷所有add文件:git reset HEAD .

➜  experimentation git:(master) ✗ git reset HEAD README.md
Unstaged changes after reset:
M       README.md
➜  experimentation git:(master) ✗ git status
On branch master
Your branch is up-to-date with 'origin/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.md

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

Tip git log與git reflog的區別
git reflog 能夠查看全部分支的全部操做記錄（包括commit,reset的操做,已經被刪除的commit記錄)
git log不能察看已經刪除的commit記錄

本地代碼已經add，已commit

---

將本地代碼多commit幾回,再來看下咱們的提交log

• 方法一(推薦)：執行git revert <commitId>

撤回到指定的版本，包括文件和狀態。

• 方法二：執行git reset <commitId>

➜  experimentation git:(master) git reset 2a6c701
Unstaged changes after reset:
M       experimentation.txt
➜  experimentation git:(master) ✗ git status
On branch master
Your branch and 'origin/master' have diverged,
and have 4 and 6 different commits each, respectively.
  (use "git pull" to merge the remote branch into yours)
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:   experimentation.txt

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

回退至指定的版本，區別以下

Tip git revert與git reset的區別 git reset是直接刪除指定的commit以前的全部commit(這是不安全的，特別是push後)，把HEAD向後移動。 git revert是一次新的commit，HEAD繼續前進，與普通的commit同樣。