With the git difflast alias, you can see a diff against your last commit:

[1] ~/grocery (master) 
$ git config --global alias.difflast 'diff --cached HEAD^' 
 
[2] ~/grocery (master) 
$ git difflast 
diff --git a/shoppingList.txt b/shoppingList.txt 
index d362b98..08e7361 100644 
--- a/shoppingList.txt 
+++ b/shoppingList.txt 
@@ -4,3 +4,4 @@ orange 
 peach 
 grape 
 blackberry 
+apricot