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我一直在玩添加和提交，並使用diff來顯示HEAD，索引和工作目錄之間的差異。使用diff，我的理解是，它應該指定哪些文件已經更改，但它也應該指定文件之間的差異（例如，如果我將「hello」寫入文件，應該說+hello（或類似的東西）當我運行diff和它比較兩者）。Git diff不列出文件的特定更改？
但是，當我使用diff時，它只顯示文件已更改;它沒有顯示這些變化是什麼。爲什麼它不顯示文件中的個別更改 - 我添加的實際文本，我已刪除的具體文本等等？如果diff不這樣做，是否有一個我可以使用它的命令？
謝謝。
要運行一個完整的測試，我刪除.git就跑，然後發現diff沒有表現出差異爲diff所有三種變體（git diff，git diff --cached和git diff HEAD）。我使用的文件是t.txt。這是我爲了可讀性而格式化的控制檯; >>是Powershell提示輸入的地方，我輸入到控制檯中;評論是我寫的，用>> # <comment>表示。這是我的控制檯輸出：
>> # Starting with nothing.
>> git status
fatal: Not a git repository (or any of the parent directories): .git
>> git init
Initialized empty Git repository in C:/Users/q/Documents/GitHub/.git/
>> ls
>> git status
On branch master
Initial commit
nothing to commit (create/copy files and use "git add" to track)
>> echo "New file created." > t.txt
>> git status
On branch master
Initial commit
Untracked files:
(use "git add <file>..." to include in what will be committed)
t.txt
nothing added to commit but untracked files present (use "git add" to track)
>> git add .
>> git status
On branch master
Initial commit
Changes to be committed:
(use "git rm --cached <file>..." to unstage)
new file: t.txt
>> #open t.txt and add a second line of text to it
>> git status
On branch master
Initial commit
Changes to be committed:
(use "git rm --cached <file>..." to unstage)
new file: t.txt
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: t.txt
>> git diff
diff --git a/t.txt b/t.txt
index e7a4f8a..fe91a49 100644
Binary files a/t.txt and b/t.txt differ
>> #How can I see the exact change?
>> #Something like: '''
>> #
>> # + This is the added line.
>> #
>> # ''' in the diff?
>> # I can take this even further by making the first commit, modifying, then staging the file
# with `git add`, then editing again, and then run all three `git-diff`s
# (git diff, git diff --cached, git diff HEAD) and none of them will specify any actual
# changes in the files; Git still just lists the files that have discrepancies, without
# listing any of the detials about /what/ is actually different.
>> git add .
>> git commit -m "Committed with the second line."
[master (root-commit) 14acc45] Committed with the second line.
1 file changed, 0 insertions(+), 0 deletions(-)
create mode 100644 t.txt
>> git diff
>> git log
commit 14acc455b16ba26cdea1661166b0ffc3fa089784
Author: q <[email protected]>
Date: Sat Nov 7 04:29:20 2015 -0800
Committed with the second line.
>> git diff HEAD
>> git diff HEAD^
fatal: ambiguous argument 'HEAD^': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'
>> #We change the file again to add a third line
>> 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: t.txt
no changes added to commit (use "git add" and/or "git commit -a")
>> git diff
diff --git a/t.txt b/t.txt
index fe91a49..006c33a 100644
Binary files a/t.txt and b/t.txt differ
>> git diff HEAD
diff --git a/t.txt b/t.txt
index fe91a49..006c33a 100644
Binary files a/t.txt and b/t.txt differ
>> git add .
>> #Modify file again.
>> git status
On branch master
Changes to be committed:
(use "git reset HEAD <file>..." to unstage)
modified: t.txt
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: t.txt
>> git diff
diff --git a/t.txt b/t.txt
index 006c33a..57a6754 100644
Binary files a/t.txt and b/t.txt differ
>> git diff HEAD
diff --git a/t.txt b/t.txt
index fe91a49..57a6754 100644
Binary files a/t.txt and b/t.txt differ
>> git diff --cached
diff --git a/t.txt b/t.txt
index fe91a49..006c33a 100644
Binary files a/t.txt and b/t.txt differ
>>## But how do they differ?
參見[這個答案]（http://stackoverflow.com/a/15009104/1517864），治療二進制文件爲文本 – jayant