git代码管理（2）—记录修改

朱雀 2022-01-28 04:51 337阅读 0赞

转自大神周沫凡：[https://mofanpy.com/tutorials/others/git/][https_mofanpy.com_tutorials_others_git]

Git book：[https://git-scm.com/book/zh/v2][https_git-scm.com_book_zh_v2]

**目录**

1. log查看修改记录

2.查看unstaged状态下的修改部分（git diff）

3.查看staged状态下的修改部分（git diff --cached）

4.同时查看staged & unstaged状态下的修改部分（git diff HEAD）

--------------------

（***commit记录了每一次的修改***）在 git 中, 每一次提交(commit)的修改, 都会被单独的保存起来. 也可以说 git 的中的所有文件都是一次次修改累积起来的. 文件好比楼房, 每个 commit 记录 了盖楼需添加或者拿走的材料. 整个施工过程也被记录了下来.

### 1. log查看修改记录 ###

如果我们对`1.txt`文件进行一次修改, 添加这行代码:

a = 1

然后我们就能在 `status` 中看到修改还没被提交（*changes not staged for commit*）的信息了.

$ git status
    
    # 输出
    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:   1.py    # 这里显示有一个修改还没被提交
    
    no changes added to commit (use "git add" and/or "git commit -a")

**我的实验代码：**

Administrator@PC201710130840 MINGW64 ~/Desktop/daily-learning/gitTUT (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:   1.txt
    
    no changes added to commit (use "git add" and/or "git commit -a")

（***修改后未提交的解决：add+commit***）所以我们先把这次修改添加 (add) 到可被提交 (commit) 的状态, 然后再提交 (commit) 这次的修改:

$ git add 1.py
    $ git commit -m "change 1"
    
    # 输出
    [master fb51216] change 1
     1 file changed, 1 insertion(+) # 提示文件有一处添加

**我的实验代码：**

Administrator@PC201710130840 MINGW64 ~/Desktop/daily-learning/gitTUT (master)
    $ git add 1.txt
    
    Administrator@PC201710130840 MINGW64 ~/Desktop/daily-learning/gitTUT (master)
    $ git commit -m "change 1"
    [master 2d350cb] change 1
     1 file changed, 1 insertion(+)

（***log：查看修改记录***）再次查看 `log`, 现在我们就能看到 `create 1.py` 和 `change 1` 这两条修改信息了. 而且做出这两条 `commit` 的 ID, 修改的 `Author`, 修改 `Date` 也被显示在上面.

$ git log
    
    # 输出
    commit fb51216b081e00db3996e14edf8ff080fab1980a
    Author: Morvan Zhou <mz@email.com>
    Date:   Tue Nov 29 00:24:50 2016 +1100
    
        change 1
    
    commit 13be9a7bf70c040544c6242a494206f240aac03c
    Author: Morvan Zhou <mz@email.com>
    Date:   Tue Nov 29 00:06:47 2016 +1100
    
        create 1.py

**我的实验代码：**

Administrator@PC201710130840 MINGW64 ~/Desktop/daily-learning/gitTUT (master)
    $ git log
    commit 2d350cbc1495ece3922acf9f3d797310215b90ab (HEAD -> master)
    Author: jinger <yu@email.com>
    Date:   Thu May 23 14:30:44 2019 +0800
    
        change 1
    
    commit d19b6a53062abfd0c981753400c5bb70b6b57d9a
    Author: jinger <yu@email.com>
    Date:   Thu May 23 14:21:08 2019 +0800
    
        1.txt

如果删除一部分代码, 也会被记录上, 比如把 `a = 1` 改成 `a = 2`, 再添加一个 `b = 1`.

### 2.查看unstaged状态下的修改部分（git diff） ###

（***unstaged状态下查看修改了什么内容***：***git diff***）如果想要查看这次还没 `add` (处于unstaged状态) 的修改部分 和上个已经 `commit` 的文件有何不同, 我们将使用 `$ git diff`:

$ git diff
    
    # 输出
    diff --git a/1.py b/1.py
    index 1337a53..ff7c36c 100644
    --- a/1.py
    +++ b/1.py
    @@ -1 +1,2 @@
    -a = 1  # 删除了 a = 1
    +a = 2  # 添加了 a = 2
    +b = 1  # 添加了 b = 1

**我的实验代码：**

Administrator@PC201710130840 MINGW64 ~/Desktop/daily-learning/gitTUT (master)
    $ git diff
    diff --git a/1.txt b/1.txt
    index d25d49e..61ce15f 100644
    --- a/1.txt
    +++ b/1.txt
    @@ -1 +1,2 @@
    -a = 1
    \ No newline at end of file
    +a = 2
    +b = 1
    \ No newline at end of file

### 3.查看staged状态下的修改部分（git diff --cached） ###

（***staged状态下查看修改了什么内容***：***git diff --cached***）如果你已经 `add` 了这次修改, 文件变成了 “可提交状态” (staged), 我们可以在 `diff` 中添加参数 `--cached` 来查看修改:

$ git add .   # add 全部修改文件
    $ git diff --cached
    
    # 输出
    diff --git a/1.py b/1.py
    index 1337a53..ff7c36c 100644
    --- a/1.py
    +++ b/1.py
    @@ -1 +1,2 @@
    -a = 1
    +a = 2
    +b = 1

**我的实验代码：**

Administrator@PC201710130840 MINGW64 ~/Desktop/daily-learning/gitTUT (master)
    $ git add .
    
    Administrator@PC201710130840 MINGW64 ~/Desktop/daily-learning/gitTUT (master)
    $ git diff --cached
    diff --git a/1.txt b/1.txt
    index d25d49e..61ce15f 100644
    --- a/1.txt
    +++ b/1.txt
    @@ -1 +1,2 @@
    -a = 1
    \ No newline at end of file
    +a = 2
    +b = 1
    \ No newline at end of file

### 4.同时查看staged & unstaged状态下的修改部分（git diff HEAD） ###

还有种方法让我们可以查看 `add` 过 (staged) 和 没 `add` (unstaged) 的修改, 比如我们再修改一下 `1.py` 但不 `add`:

a = 2
    b = 1
    c = b

目前 `a = 2` 和 `b = 1` 已被 `add`, `c = b` 是新的修改, 还没被 `add`.

以下是diff 三种形式的不同结果

$ git diff HEAD
    $ git diff 
    $ git diff --cached

如下：

# 对比三种不同 diff 形式
    $ git diff HEAD     # staged & unstaged
    
    @@ -1 +1,3 @@
    -a = 1  # 已 staged
    +a = 2  # 已 staged
    +b = 1  # 已 staged
    +c = b  # 还没 add 去 stage (unstaged)
    -----------------------
    $ git diff          # unstaged
    
    @@ -1,2 +1,3 @@
     a = 2  # 注: 前面没有 +
     b = 1  # 注: 前面没有 +
    +c = b  # 还没 add 去 stage (unstaged)
    -----------------------
    $ git diff --cached # staged
    
    @@ -1 +1,2 @@
    -a = 1  # 已 staged
    +a = 2  # 已 staged
    +b = 1  # 已 staged

**我的实验代码：**

Administrator@PC201710130840 MINGW64 ~/Desktop/daily-learning/gitTUT (master)
    $ git diff HEAD
    diff --git a/1.txt b/1.txt
    index d25d49e..ac13cf6 100644
    --- a/1.txt
    +++ b/1.txt
    @@ -1 +1,3 @@
    -a = 1
    \ No newline at end of file
    +a = 2
    +b = 1
    +c = b
    \ No newline at end of file
    
    Administrator@PC201710130840 MINGW64 ~/Desktop/daily-learning/gitTUT (master)
    $ git diff
    diff --git a/1.txt b/1.txt
    index 61ce15f..ac13cf6 100644
    --- a/1.txt
    +++ b/1.txt
    @@ -1,2 +1,3 @@
     a = 2
    -b = 1
    \ No newline at end of file
    +b = 1
    +c = b
    \ No newline at end of file
    
    Administrator@PC201710130840 MINGW64 ~/Desktop/daily-learning/gitTUT (master)
    $ git diff --cached
    diff --git a/1.txt b/1.txt
    index d25d49e..61ce15f 100644
    --- a/1.txt
    +++ b/1.txt
    @@ -1 +1,2 @@
    -a = 1
    \ No newline at end of file
    +a = 2
    +b = 1
    \ No newline at end of file

为了下节内容, 我们保持这次修改, 全部 `add` 变成 `staged` 状态, 并 `commit`.

$ git add .
    $ git commit -m "change 2"
    
    # 输出
    [master 6cc6579] change 2
     1 file changed, 3 insertions(+), 1 deletion(-)

**我的实验代码：**

Administrator@PC201710130840 MINGW64 ~/Desktop/daily-learning/gitTUT (master)
    $ git add .
    
    Administrator@PC201710130840 MINGW64 ~/Desktop/daily-learning/gitTUT (master)
    $ git commit -m "change 2"
    [master 2f7e561] change 2
     1 file changed, 3 insertions(+), 1 deletion(-)

总结：

*  **git log **查看修改记录
 *  **git diff** 查看unstaged（未add）状态下的修改部分
 *  **git diff --cached **查看staged（已add）状态下的修改部分
 *  **git diff  HEAD** 查看unstaged（已add + 未add）状态下的修改部分

[https_mofanpy.com_tutorials_others_git]: https://mofanpy.com/tutorials/others/git/
[https_git-scm.com_book_zh_v2]: https://git-scm.com/book/zh/v2