1. 引入
git clean 是用来删除 git 仓库中没有被跟踪的文件的命令，在想要快速清理 git 仓库（比如，删除仓库中所有没有跟踪的文件，清除编译生成的临时文件）时很有用。是相比别的git子命令， git clean的配置选项比较少，使用起来简单一些，这里写一个简要教程。
友情提示：git clean真的会删除文件，而且没法用git命令来恢复（因为没有被 git 跟踪），所以使用git clean前务必慎重，建议每次删除文件之前先加--dry-run 选项来验证会删除哪些文件，确保没有误删。
2. git clean 选项的含义
先创建一个简单的git 仓库环境来比较清晰地展示各个选项的效果:
代码语言：javascript复制mkdir /tmp/git_clean_demo
cd /tmp/git_clean_demo
git init
touch a.py b.py
git add a.py
mkdir -p folder0/folder00
mkdir -p folder0/folder01
touch folder0/folder0.py
touch folder0/folder00/folder00.py
touch folder0/folder01/folder01.py
git add folder0/folder0.py
git add folder0/folder00/
touch folder0/folder00/folder00_v2.py
echo "*.pyc" >> .gitignore
touch a.pyc
git add .gitignore用git status 查看一下文件跟踪状态：
On branch main
No commits yet
Changes to be committed:
(use "git rm --cached <file>..." to unstage)
new file: a.py
new file: folder0/folder0.py
new file: folder0/folder00/folder00.py
Untracked files:
(use "git add <file>..." to include in what will be committed)
b.py
folder0/folder00/folder00_v2.py
folder0/folder01/在 Git 的800多个配置选项中，只有一项是关于git clean 命令的：clean.requireForce。这个选项的意思是，使用git clean 时，必须加-f或者--force 参数才能删除文件，否则并不会删除文件，执行时会提示下面信息：
$ git clean
fatal: clean.requireForce defaults to true and neither -i, -n, nor -f given; refusing to clean这是一个很好的保护文件不被轻易删除的选项，建议不要修改默认值。
所以 -f/--force的选项的含义就是强制删除，实际删除文件时必带此选项。
-n/--dry-run表示不实际删除任何东西，只是空跑一下，用来看哪些文件会被删除掉。对于这种破坏性的命令，增加--dry-run选项真的是一个非常好的设定。
另一个很重要的选项是-d，表示进入未跟踪的目录来递归删除文件。注意对已经跟踪的目录，不加-d 命令也会清理其中的未跟踪文件，一定注意！
比如刚才创建的git仓库，不加-d 选项删除时结果如下:
$ git clean -f --dry-run
Would remove b.py
Would remove folder0/folder00/folder00_v2.py加了 -d选项：
$ git clean -f -d --dry-run
Would remove b.py
Would remove folder0/folder00/folder00_v2.py
Would remove folder0/folder01/可以看到不管加不加-d，已经跟踪的目录下的未跟踪文件都会被删除；而只有加了-d，未跟踪的目录和下面的文件才会被删除。
-q/--quiet表示静默操作，除了错误，别的信息不显示，实际效果：
$ git clean -f -d -q --dry-run可以看到没有任何输出。
-i/--interactive 表示交互式地删除文件，用于对文件删除进行精细操作。进入交互式界面后，又可以分按模式删除、按数字删除、每次删除前询问几种方式，具体看下面的交互式会话：
$ git clean -f -d -i --dry-run
Would remove the following items:
b.py folder0/folder00/folder00_v2.py folder0/folder01/
*** Commands ***
1: clean 2: filter by pattern 3: select by numbers 4: ask each 5: quit 6: help
What now> h
clean - start cleaning
filter by pattern - exclude items from deletion
select by numbers - select items to be deleted by numbers
ask each - confirm each deletion (like "rm -i")
quit - stop cleaning
help - this screen
? - help for prompt selection
Would remove the following items:
b.py folder0/folder00/folder00_v2.py folder0/folder01/
*** Commands ***
1: clean 2: filter by pattern 3: select by numbers 4: ask each 5: quit 6: help
What now> c
Would remove b.py
Would remove folder0/folder00/folder00_v2.py
Would remove folder0/folder01/按规则忽略文件，也就是匹配到规则的图片不进行删除：
代码语言：javascript复制$ git clean -f -d -i --dry-run
Would remove the following items:
b.py folder0/folder00/folder00_v2.py folder0/folder01/
*** Commands ***
1: clean 2: filter by pattern 3: select by numbers 4: ask each 5: quit 6: help
What now> f
b.py folder0/folder00/folder00_v2.py folder0/folder01/
Input ignore patterns>> *folder*
b.py
Input ignore patterns>>
Would remove the following item:
b.py
*** Commands ***
1: clean 2: filter by pattern 3: select by numbers 4: ask each 5: quit 6: help
What now> c
Would remove b.py按数字删除：
代码语言：javascript复制$ git clean -f -d -i --dry-run
Would remove the following items:
b.py folder0/folder00/folder00_v2.py folder0/folder01/
*** Commands ***
1: clean 2: filter by pattern 3: select by numbers 4: ask each 5: quit 6: help
What now> s
1: b.py 2: folder0/folder00/folder00_v2.py 3: folder0/folder01/
Select items to delete>> 1
* 1: b.py 2: folder0/folder00/folder00_v2.py 3: folder0/folder01/
Select items to delete>> 2
* 1: b.py * 2: folder0/folder00/folder00_v2.py 3: folder0/folder01/
Select items to delete>> 3
* 1: b.py * 2: folder0/folder00/folder00_v2.py * 3: folder0/folder01/
Select items to delete>> 4
Huh (4)?
* 1: b.py * 2: folder0/folder00/folder00_v2.py * 3: folder0/folder01/
Select items to delete>> 5
Huh (5)?
* 1: b.py * 2: folder0/folder00/folder00_v2.py * 3: folder0/folder01/
Select items to delete>>
Would remove the following items:
b.py folder0/folder00/folder00_v2.py folder0/folder01/
*** Commands ***
1: clean 2: filter by pattern 3: select by numbers 4: ask each 5: quit 6: help
What now> c
Would remove b.py
Would remove folder0/folder00/folder00_v2.py
Would remove folder0/folder01/注意看输入大于未跟踪文件数目的数字时的Huh，有点喜感。
-e/--exclude表示删除时排除满足后面模式的文件，比如-e "*/" 表示排除所有文件夹，-e "*_v2.py"表示排除所有以_v2.py结尾的文件：
$ git clean -f -d -e "*/" --dry-run
Would remove b.py
$ it clean -f -d -e "*_v2.py" --dry-run
Would remove b.py
Would remove folder0/folder01-x 表示不使用.gitignore中的规则。如果不加这个选项，默认会跳过.gitignore 规则中的文件，启用这个选项后会将.gitignore 中的文件也删除，比如创建示例仓库时我们忽略了*.pyc，前面的结果中都没跳过了这一类文件，加了-x选项后输出如下:
$ git clean -f -d -x --dry-run
Would remove a.pyc
Would remove b.py
Would remove folder0/folder00/folder00_v2.py
Would remove folder0/folder01/a.pyc 也被删除掉了。
-X选项（大写的X）与-x 相反，只删除满足.gitignore 中规则的文件：
$ git clean -f -d -X --dry-run
Would remove a.pyc3. 总结
实际实践中，我对git clean 用的还不多(严格来说正经使用只用过一次)，本文中如果错误，欢迎批评指正。
