如何使用 git diff：提交、分支、文件和并排

不带参数的`git diff` 显示您尚未暂存的更改。 `git diff --staged` 显示下一次提交将包含的内容，而 `git diff main feature` 比较两个分支。 将 -- path/to/file 添加到任何表单以将其限制为一个文件。 Git 本身在终端中没有并排视图。为此，您需要 git difftool 或 Git GUI。

我需要哪个 git diff 命令？

如何读取 git diff 输出？

diff --git a/src/search.ts b/src/search.ts
index 4e1f2a0..9b3c7d1 100644
--- a/src/search.ts
+++ b/src/search.ts
@@ -12,7 +12,7 @@ export function search(query: string) {
   const terms = tokenize(query);
-  return index.find(terms, { limit: 20 });
+  return index.find(terms, { limit: 50 });
 }

• --- 和 +++ 分别命名文件的旧版本和新版本。
• @@ -12,7 +12,7 @@ 是一个大块头：每个版本中第 12 行起 7 行。
• 以 - 开头的行被删除，以 + 开头的行被添加，其余的是上下文。

阅读差异课程 逐步练习这一点。

如何区分两个提交？

# any two commits, older first
git diff 3e52f10 7c1d9ab

# the last commit against the one before it
git diff HEAD~1 HEAD

# one commit against its parent, with the message
git show 7c1d9ab

如何区分两个分支？

# the tips of both branches
git diff main feature

# only what feature added since it left main
git diff main...feature

# a remote branch
git fetch origin
git diff main origin/main

如何比较一个文件？

# working copy against the last commit
git diff HEAD -- src/search.ts

# the same file on two branches
git diff main feature -- src/search.ts

# a file at two commits
git diff HEAD~3 HEAD -- src/search.ts

# two files outside any repository
git diff --no-index old.txt new.txt

如何让 git diff 忽略空格？

这些仅影响差异显示的内容。他们不会改变所暂存或提交的内容。当重新缩进使整个文件看起来发生变化时，需要使用 -w。

如何仅列出已更改的文件？

# names only
git diff --name-only main...feature

# names with A, M, D or R
git diff --name-status main...feature

# lines added and removed per file
git diff --stat main...feature

我如何查看哪些单词发生了变化？

git diff --word-diff
git diff --color-words

单词差异有助于处理长行，例如 Markdown 段落，其中一个更改的单词会将整行标记为已更改。

如何获得并排差异？

普通的 git diff 打印单列并且没有并排选项。您可以通过三种方式获取两列：将 git difftool 指向 diff 程序、安装终端分页器（例如 delta）或使用 Git GUI。

# pick a tool once
git config --global diff.tool vimdiff

# open each changed file in it
git difftool main...feature

# skip the prompt for each file
git difftool -y

有关每个选项，请参阅选择和使用差异视图 和比较引用。