Hi Junio et al,
j-c-diff is "used" in the docs within git, git-annex, and other places
discussing git. But I failed to find it to seek for an ultimate prototypical
example of the diff command used by git ppl ;)
$> git log -Sj-c-diff -p Documentation/gitattributes.txt
commit 2cc3167c688d1c91bc4cb9b1caa737b9d4971056
Author: Junio C Hamano <junkio@xxxxxxx>
Date: Mon Apr 23 00:21:02 2007 -0700
Document "diff=driver" attribute
Signed-off-by: Junio C Hamano <junkio@xxxxxxx>
diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt
index 126871756d..d2edb9b14a 100644
--- a/Documentation/gitattributes.txt
+++ b/Documentation/gitattributes.txt
@@ -151,8 +151,34 @@ Unspecified::
text, it is treated as text. Otherwise it would
generate `Binary files differ`.
-Any other value set to `diff` attribute is ignored and git acts
-as if the attribute is left unspecified.
+String::
+
+ Diff is shown using the specified custom diff driver.
+ The driver program is given its input using the same
+ calling convention as used for GIT_EXTERNAL_DIFF
+ program.
+
+
+Defining a custom diff driver
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The definition of a diff driver is done in `gitconfig`, not
+`gitattributes` file, so strictly speaking this manual page is a
+wrong place to talk about it. However...
+
+To define a custom diff driver `jcdiff`, add a section to your
+`$GIT_DIR/config` file (or `$HOME/.gitconfig` file) like this:
+
+----------------------------------------------------------------
+[diff "jcdiff"]
+ command = j-c-diff
+----------------------------------------------------------------
+
+When git needs to show you a diff for the path with `diff`
+attribute set to `jcdiff`, it calls the command you specified
+with the above configuration, i.e. `j-c-diff`, with 7
+parameters, just like `GIT_EXTERNAL_DIFF` program is called.
+See gitlink:git[7] for details.
Cheers!
--
Yaroslav O. Halchenko
Center for Open Neuroscience http://centerforopenneuroscience.org
Dartmouth College, 419 Moore Hall, Hinman Box 6207, Hanover, NH 03755
Phone: +1 (603) 646-9834 Fax: +1 (603) 646-1419
WWW: http://www.linkedin.com/in/yarik
