What is the git diff command for?

Question

I asked that question a little while ago here at SOPT.

Some doubts arose, and then the user @Anthonyaccioly recommended me to ask this question.

What is the command for git diff?

Answer 1

diff serves to verify differences between commits, files and directory trees.

Examples:

• git diff: Displays all differences between your local copy and the synchronized index;
• git diff –cached: Displays all differences between the synchronized index and the last commit;
• git diff HEAD: Displays all differences between your local copy and the last commit accomplished;

Answer 2

Basically, the command is git diff serves to show differences between files.

As an example, see an output of this command, showing the changes in the arquivo:

diff --git a/arquivo b/arquivo
index 10ff2df..84d4fa2 100644
--- a/arquivo
+++ b/arquivo
@@ -1,5 +1,5 @@
 linha1
 linha2
-esta linha foi removida
 linha4
 linha5
+esta linha foi adicionada

It can be used both to show differences between files not staged (files that have had some change):

git diff

Or files staged and not staged (in addition to the files cited above, it also shows changes to files added with git add):

git diff HEAD

Or even between commits:

git diff b4cb8d9..9c5733f

I believe the above commands are the most common ways to use the diff. As the command is very flexible and has several options of use, I suggest taking a look at official documentation.