git-config-set: support selecting values by non-matching regex
[git.git] / README
diff --git a/README b/README
index 0ee49d4..36fef6e 100644 (file)
--- a/README
+++ b/README
@@ -396,8 +396,48 @@ git-commit-tree will return the name of the object that represents
 that commit, and you should save it away for later use. Normally,
 you'd commit a new `HEAD` state, and while git doesn't care where you
 save the note about that state, in practice we tend to just write the
-result to the file `.git/HEAD`, so that we can always see what the
-last committed state was.
+result to the file pointed at by `.git/HEAD`, so that we can always see
+what the last committed state was.
+
+Here is an ASCII art by Jon Loeliger that illustrates how
+various pieces fit together.
+
+------------
+
+                     commit-tree
+                      commit obj
+                       +----+
+                       |    |
+                       |    |
+                       V    V
+                    +-----------+
+                    | Object DB |
+                    |  Backing  |
+                    |   Store   |
+                    +-----------+
+                       ^
+           write-tree  |     |
+             tree obj  |     |
+                       |     |  read-tree
+                       |     |  tree obj
+                             V
+                    +-----------+
+                    |   Index   |
+                    |  "cache"  |
+                    +-----------+
+         update-index  ^
+             blob obj  |     |
+                       |     |
+    checkout-index -u  |     |  checkout-index
+             stat      |     |  blob obj
+                             V
+                    +-----------+
+                    |  Working  |
+                    | Directory |
+                    +-----------+
+
+------------
+
 
 6) Examining the data
 ~~~~~~~~~~~~~~~~~~~~~
@@ -424,7 +464,7 @@ tend to be small and fairly self-explanatory. In particular, if you
 follow the convention of having the top commit name in `.git/HEAD`,
 you can do
 
-               git-cat-file commit $(cat .git/HEAD)
+               git-cat-file commit HEAD
 
 to see what the top commit was.