Git之基本用法

git的工作目录|暂存区|版本库|远程仓库

工作目录：是用户在本地进行文件操作的实际目录，即项目所在的目录。用户可以在工作目录中创建、修改、删除文件等，这些操作都是在本地进行的，尚未被 Git 跟踪和管理。
暂存区：也称为索引（Index），是工作目录和版本库之间的中间区域。当使用git add命令将文件添加到暂存区后，这些文件就准备好被提交到版本库中了。暂存区可以让用户将多次的文件修改组合成一个逻辑上的提交。
版本库：也叫 Git 仓库，包含了项目的所有版本历史和相关的元数据，存储在隐藏的.git目录中。当执行git commit命令时，暂存区中的文件会被提交到版本库中，形成一个新的提交记录。
远程仓库：是位于网络上的共享版本库，用于团队成员之间共享和协作开发项目。远程仓库可以是自己搭建的服务器，也可以是像 GitHub、GitLab 这样的代码托管平台上的仓库。本地仓库可以与远程仓库进行同步，将本地的提交推送到远程仓库，或者从远程仓库拉取最新的提交。

git的文件状态

git中文件有以下常见的4种状态：未跟踪、未修改、已修改、已暂存

未跟踪（Untracked）
- 含义：文件在工作目录中，但尚未被 Git 纳入版本控制范围，Git 不知道有这个文件的存在。
- 场景：当在工作目录中新建一个文件，还没有执行git add命令将其添加到暂存区时，该文件就处于未跟踪状态。比如在项目目录下新建了一个new_file.txt文件，此时git status命令的输出会显示该文件为未跟踪文件。
已跟踪（Tracked）
- 含义：文件已经被 Git 纳入版本控制，Git 会对其进行跟踪，记录文件的变更历史。已跟踪文件又可细分为以下三种状态。
- unmodified（未修改）
  - 含义：文件在工作目录中，且自从上次提交或更新后，其内容没有发生任何改变，与版本库中的对应版本保持一致。
  - 示例：如果项目中有一个styles.css文件，在上次提交后没有对其进行任何编辑操作，那么它就处于unmodified状态。
- modified（已修改）
  - 含义：文件在工作目录中被修改了，其内容与版本库中的对应版本不一致，Git 检测到了这种变化，但这些修改还未被添加到暂存区。
  - 示例：对styles.css文件进行了样式调整，保存后，该文件就处于modified状态，git status命令会显示该文件被修改，提示可以选择将这些修改添加到暂存区或者丢弃。
- staged（已暂存）
  - 含义：已修改的文件通过git add命令被添加到了暂存区，准备好被提交到版本库中，此时文件的修改会被包含在即将进行的提交中。
  - 示例：在对styles.css文件修改后，执行git add styles.css，该文件就从modified状态变为staged状态，git status命令会显示该文件已被暂存，等待提交。

以下所有操作都在实际工作目录下进行

Git本地配置

在正式演示git的添加，提交，撤回等操作前，我们需要对git进行简单的配置。

Git配置分为系统--system，全局--global，本地--local三个不同级别，优先级依次递减，其中如果存在重复的配置，那么低级别配置会覆盖高级别配置

local配置：存在每个git仓库的.git/config文件中
global配置：存在用户目录下的.gitconfig文件中
system配置：存在${profile}/etc/gitconfig中，${prefix}为git的安装目录

git的提交会引用用户的用户名以及邮箱(可以使用github提供的匿名邮箱)，因此这里需要执行命令进行设置：

1 2	git config --global user.name "DopamineNone" git config --global user.email 123919976+DopamineNone@users.noreply.github.com

相应的在配置文件中就会出现：

1
2
3

[user]
	name = DopamineNone
	email = 123919976+DopamineNone@users.noreply.github.com

除此之外，还可以为git命令设置别名，比如：

1	git config --global alias.ad "add ."

相当于为git add .起了别名git ad

本地工作目录|暂存区|版本库操作

查看文件状态

git status: 使用git status命令可以查看当前工作目录和暂存区的状态，了解哪些文件被修改、新增或删除，以及哪些文件已被暂存准备提交。

查看提交历史

git log可以查看版本库的提交日志
使用--graph选项可以查看git提交图谱

初始化仓库

git init: 会将当前的目录初始化化为git仓库，生成一个隐藏文件夹.git，用于存储与版本控制相关的信息

这里实践一下：

DopamineNone@DM MINGW64 ~/Projects/git_test
$ git init
Initialized empty Git repository in C:/Users/DopamineNone/Projects/git_test/.git/

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git status
On branch master

No commits yet

nothing to commit (create/copy files and use "git add" to track)

可见刚初始化后的仓库什么都没有

添加至暂存区（untracked, modified -> staged）

git add [file]
- 这个操作的目的是为了将未跟踪或已修改状态的文件推至暂存区中
- 可以用git add .将仓库中所有未跟踪或已修改状态的文件推至暂存区

实践一下：

1. 创建一个新文件file1.txt，查看状态(untracked)

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ touch file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git status
On branch master

No commits yet

Untracked files:
  (use "git add <file>..." to include in what will be committed)
        file1.txt

nothing added to commit but untracked files present (use "git add" to track)

将file1.txt推送至暂存区，查看状态(staged，这里提示词为changes to be committed，即将要提交的变化); 状态变化：untracked -> staged

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git add file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git status
On branch master

No commits yet

Changes to be committed:
  (use "git rm --cached <file>..." to unstage)
        new file:   file1.txt

修改file1.txt，查看状态(modified)；这里to be committed的是暂存区中file1.txt的快照；状态变化：staged -> modified

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ echo "hello git" > file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git status
On branch master

No commits yet

Changes to be committed:
  (use "git rm --cached <file>..." to unstage)
        new file:   file1.txt

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
        modified:   file1.txt

将file1.txt添加至暂存区，查看状态(staged); 状态变化（modifed -> staged）；状态变化：modified -> staged

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git add file1.txt
warning: in the working copy of 'file1.txt', LF will be replaced by CRLF the next time Git touches it

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git status
On branch master

No commits yet

Changes to be committed:
  (use "git rm --cached <file>..." to unstage)
        new file:   file1.txt

提交暂存区文件(staged -> unmodified)

git commit -m "message"提交暂存区内容至版本库

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git commit -m "init project"
[master (root-commit) 1384bf0] init project
 1 file changed, 1 insertion(+)
 create mode 100644 file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git status
On branch master
nothing to commit, working tree clean

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git log
commit 1384bf0b39111d1f33ffb501f609d0c88797f422 (HEAD -> master)
Author: DopamineNone <c20160419raytheon@163.com>
Date:   Wed Jan 8 13:39:46 2025 +0800
    init project

查看不同区域/分支的差异

git diff可以显示不同区域/分支中的内容差异，包括

查看工作目录与暂存区的差异

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ echo "hello world" > file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git diff file1.txt
warning: in the working copy of 'file1.txt', LF will be replaced by CRLF the next time Git touches it
diff --git a/file1.txt b/file1.txt
index 8d0e412..3b18e51 100644
--- a/file1.txt
+++ b/file1.txt
@@ -1 +1 @@
-hello git
+hello world

查看暂存区与版本库的差异

需要加上选项--staged或--cached

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git add file1.txt
warning: in the working copy of 'file1.txt', LF will be replaced by CRLF the next time Git touches it

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git diff --staged file1.txt
diff --git a/file1.txt b/file1.txt
index 8d0e412..3b18e51 100644
--- a/file1.txt
+++ b/file1.txt
@@ -1 +1 @@
-hello git
+hello world

查看不同提交版本间的差异

git diff <commit1> <commit2>

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git commit -m "replace git by world"
[master 407586a] replace git by world
 1 file changed, 1 insertion(+), 1 deletion(-)

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git log
commit 407586abfd0b5a0239e63dc582abbd5d752edaa0 (HEAD -> master)
Author: DopamineNone <xxx>
Date:   Thu Jan 9 21:05:26 2025 +0800

    replace git by world

commit 1384bf0b39111d1f33ffb501f609d0c88797f422
Author: DopamineNone <xxx>
Date:   Wed Jan 8 13:39:46 2025 +0800

    init project

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git diff 407586abfd0b5a0239e63dc582abbd5d752edaa0 1384bf0b39111d1f33ffb501f609d0c88797f422
diff --git a/file1.txt b/file1.txt
index 3b18e51..8d0e412 100644
--- a/file1.txt
+++ b/file1.txt
@@ -1 +1 @@
-hello world
+hello git

查看两个分支之间的差异

git diff <branch1> <branch2>，暂不做演示

撤销工作目录的修改（modified -> unmodified | staged）

这里撤销的只是还没提交至暂存区中的修改

将file1.txt的内容清空，查看状态（modified）

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ echo "" > file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git status
On branch master

No commits yet

Changes to be committed:
  (use "git rm --cached <file>..." to unstage)
        new file:   file1.txt

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
        modified:   file1.txt

使用git restore <file>命令撤回修改

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git restore file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git status
On branch master

No commits yet

Changes to be committed:
  (use "git rm --cached <file>..." to unstage)
        new file:   file1.txt

撤销暂存区的修改

这里分两种情况：

仅将暂存区中文件内容恢复至最近的提交版本，但不修改工作区的文件内容
将暂存区和工作区中的文件内容恢复至最近的提交中

仅撤销暂存区的修改

使用git reset <file>或git restore --staged <file>

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ echo "" > file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git add file1.txt
warning: in the working copy of 'file1.txt', LF will be replaced by CRLF the next time Git touches it

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git diff --staged file1.txt
diff --git a/file1.txt b/file1.txt
index 3b18e51..8b13789 100644
--- a/file1.txt
+++ b/file1.txt
@@ -1 +1 @@
-hello world
+

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git reset file1.txt
Unstaged changes after reset:
M       file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git diff --staged file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git diff file1.txt
warning: in the working copy of 'file1.txt', LF will be replaced by CRLF the next time Git touches it
diff --git a/file1.txt b/file1.txt
index 3b18e51..8b13789 100644
--- a/file1.txt
+++ b/file1.txt
@@ -1 +1 @@
-hello world
+

撤销工作目录和暂存区的修改

使用git checkout HEAD <file>命令

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git add file1.txt
warning: in the working copy of 'file1.txt', LF will be replaced by CRLF the next time Git touches it

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git diff file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git diff --staged file1.txt
diff --git a/file1.txt b/file1.txt
index 3b18e51..8b13789 100644
--- a/file1.txt
+++ b/file1.txt
@@ -1 +1 @@
-hello world
+

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git checkout HEAD file1.txt
Updated 1 path from 8242445

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git diff --staged file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git diff file1.txt

撤销提交记录

撤销提交可以由两种git命令实现: git reset和git revert，但两者的效果不同

git reset [option] <commit> 分为三种情况：

仅将目标版本之后commit移出，不改变暂存区和工作目录的内容
将目标版本之后commit移出，恢复暂存区内容为当前版本，但不改变工作目录内容
将版本库、暂存区、工作目录的内容恢复至目标提交版本。

而git revert <commit>表示，提交一个与目标commit的效果相反的commit，从而实现仅撤回某一版本的变化的效果（例如：commit1为在之前版本上新增了func1，那么git revert commit1作用为提交一个删除了func1的commit），撤回的影响包括版本库，暂存区和工作目录

仅撤销版本库提交

使用git reset --soft <commit>表示撤回到哪个提交记录，如果仅撤回最近的一次提交，可以使用git reset --soft HEAD~1, HEAD指向本分支最新的提交，~1表示HEAD的前一次提交

下面将git记录回溯至“hello git”

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git log
commit 407586abfd0b5a0239e63dc582abbd5d752edaa0 (HEAD -> master)
Author: DopamineNone <xxx>
Date:   Thu Jan 9 21:05:26 2025 +0800

    replace git by world

commit 1384bf0b39111d1f33ffb501f609d0c88797f422
Author: DopamineNone <xxx>
Date:   Wed Jan 8 13:39:46 2025 +0800

    init project

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git reset --soft HEAD~1

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git diff --staged file1.txt
diff --git a/file1.txt b/file1.txt
index 8d0e412..3b18e51 100644
--- a/file1.txt
+++ b/file1.txt
@@ -1 +1 @@
-hello git
+hello world

仅撤销版本库提交和恢复暂存区

使用git reset <commit>即可，等同于git reset --mixed <commit>

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git commit -m "replace git by world 2"
[master b166262] replace git by world 2
 1 file changed, 1 insertion(+), 1 deletion(-)

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git log
commit b166262647db5d50e1ea59f644f59845f6fc002b (HEAD -> master)
Author: DopamineNone <xxx>
Date:   Thu Jan 9 21:34:08 2025 +0800

    replace git by world 2

commit 1384bf0b39111d1f33ffb501f609d0c88797f422
Author: DopamineNone <xxx>
Date:   Wed Jan 8 13:39:46 2025 +0800

    init project

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git reset HEAD~1
Unstaged changes after reset:
M       file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git diff --staged file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git diff file1.txt
diff --git a/file1.txt b/file1.txt
index 8d0e412..3b18e51 100644
--- a/file1.txt
+++ b/file1.txt
@@ -1 +1 @@
-hello git
+hello world

撤销所有区域的变化至上个提交

使用git reset --hard <commit>，下例中工作区的内容最后也被回溯至”hello git”

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git add file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git commit -m "replace git by world 3"
[master e2f0737] replace git by world 3
 1 file changed, 1 insertion(+), 1 deletion(-)

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git reset --hard HEAD~1
HEAD is now at 1384bf0 init project

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git diff file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ cat file1.txt
hello git

仅撤回某一版本的变化

通过git revert <commit1>实现，如：

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ echo " world" >> file1.txt

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ cat file1.txt
hello git
 world

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git add file1.txt
warning: in the working copy of 'file1.txt', LF will be replaced by CRLF the next time Git touches it

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git commit -m "add world"
[master bc2c3ea] add world
 1 file changed, 1 insertion(+)

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git revert HEAD
[master a52db43] Revert "add world"
 1 file changed, 1 deletion(-)

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ git log
commit a52db43677856b9e37e880308c3581bdb53f34eb (HEAD -> master)
Author: DopamineNone <xxx>
Date:   Thu Jan 9 22:38:33 2025 +0800

    Revert "add world"

    This reverts commit bc2c3ea660eea6c38d5d3c8ca03f51935a1028ec.

commit bc2c3ea660eea6c38d5d3c8ca03f51935a1028ec
Author: DopamineNone <xxx>
Date:   Thu Jan 9 22:33:29 2025 +0800

    add world

commit 1384bf0b39111d1f33ffb501f609d0c88797f422
Author: DopamineNone <xxx>
Date:   Wed Jan 8 13:39:46 2025 +0800

    init project

DopamineNone@DM MINGW64 ~/Projects/git_test (master)
$ cat file1.txt
hello git

git reset 和 git revert的区别：

git reset的作用是撤回至先前的某个版本，而git revert是通过提交一个相反的commit，仅“撤回”某个版本的变化

当撤回一个公共分支（多人合作使用的分支）的某个commit时，用于公共分支的commit只增不减（若删除了公共分支的commit，会导致与其他人的本地分支产生冲突），因此这时候使用git revert最稳妥；但如果时个人分支（即该分支不会被他人直接引用），可以使用git reset 配合 git push -f实现提交撤回，并使日志更加简洁

更多git基本使用方法请见Git 基本用法(2)